EEVblog Electronics Community Forum
General => General Chat => Topic started by: odessa on April 17, 2012, 05:24:59 pm

Hi Guys,
I want to buy a good calculator for electronics use, anyone have any suggestions or recomendations ?
Thanks
Jay

fx82AU, its been superceded, but i'm just used to that model, a good scientific calculator

I still use the old Casio FX115 I bought way back in the 1980s.
Does multiple base math and is solar powered.
I'd rather have something that handled RPN but the Casio is what I have.

Microsoft mathematics, and it's free.

calc.exe :D
Yeah, its sad. My fx82 died.
I'll probably by an HP RPN sometime

I would definitely get the reissue of the HP15C while it is available.
http://www.shopping.hp.com/product/calculator/Scientific/1/storefronts/NW250AA%2523ABA (http://www.shopping.hp.com/product/calculator/Scientific/1/storefronts/NW250AA%2523ABA)
It is not a graphing calculator, but it in many people's opinions the HP11c and the 15C were the best calculators HP ever made. Very long battery life, a great size and form factor. Great keys.
It is RPN which I would always go for personally, but you may want a standard algebraic calculator.
Richard.

Usually I use ipython on my laptop :)
But for hw, I like the TI89 because it supports units, so you can get a quick check whether the math you just did make sense or not. And there is plenty of mod for it as well, including RPN modes.

Thanks guys, very helpful...
Can't believe how expensive those HP's are :o
I'm gonna go for the Casio Fx
Cheers :)

I like The Casio CM100
(http://casio.ledudu.com/images/calculs/casio/machines/cm100_2.jpg)
AFAIK the only calc that has hex and logical functions as primary buttons as opposed to being buried.
A bit short on maths functions though.
They do seem to have a habit of spontaneously evaporating  I've had 2 over the years & managed somehow to lose both, despite them never going out of a (nonshared) office!

The HP35S that is out now is one of the closest to the old HP designs where they cared about useability. I will be buying one myself.
I have an old HP32SII which is a very nice little calculator.
I also have an HP48GX, and on any computing device that I can find an emulator for it I also have it installed. Right now an HP48 emulator is on all my computers and all my androids.
http://www.hpcalc.org/ (http://www.hpcalc.org/)
As you can see I really like RPN calculators. They are just easier to use when thinking through a problem. I also like HP for the most part.

I'll be honest ... I had to google RPN :D
Also my teenage daughter has been a great help showing me how to use a scientific calculator ... .god I feel old :(

I've been using (Casio fx991EX plus) for more than 3 years now and I'm pretty pleased with it.
(http://casio.ledudu.com/images/calculs/casio/machines/zoom/fx991esplus.jpg)

The 6 key has just failed me on my trusty Casio FX9700G graphic calculator after 19 years and one drop from a 12 storey building. Going to take it apart and see if I can repair it.
I am now using sage maths to replace it. Incredibly powerful and free. Similar to Mathematica in many ways.
However, I am tempted to get a HP50G as I'm struggling with breaking away from a physical calculator.
All the ipad calcs seem to either be crap or don't break away from the constraints of a physical calculator.

I would definitely get the reissue of the HP15C while it is available.
Dad has bought one of those, quite nice.

Unfortunately, choosing a calculator is a touch complicated if you're in school.
For general purpose electronics use, any scientific calculator will do. I like the Casios, FX 260 is as close to ones I used heavily in school in the 1980s [ older Casios are more durably made and keys laid out better, I still use my 30+ year old college Fx100 today].
This is really for bench fixups, back of napkin designs or estimates. Portability, maintenance free, and low cost are most important, this is about $8 at Walmart or $11 at Amazon, fully solar no batteries. Its very light too, and wont' load your shirt pocket, so I have 3: one in the lab, one in my work bag and one in the living room:
(http://ecx.imagesamazon.com/images/I/51OU5gwGUL._SL500_AA300_.jpg)
For just $13 more you can get another with gobs of added functions, even graphing, but it also makes the calculator bigger, adds more keystrokes, and hard to shirt pocket.
You don't really need more than ~ 8 bit accuracy for making back of envelope calculations. if you need to do more complex or accurate calculations, its best to use a PC so the outputs are fed into SPICE or other simulator, has superb graphing, and the free Windows calculators provide all the basics. Also if you track calculations with a 'paper tape' on a PC its far easier to manipulate.
For school, learning math concepts and being that some classes do not allow you to use a PC, PC provides far better graphing capabilities, you have to go with what the class recommends.

Ya have to be careful with with using an RPN calculator for school.
They can sometimes be banned due to their programmability.
You don't want to get used to using RPN and then on the day of the test find out you can't use it.
Also the teachers don't like you using a better calculator than theirs. 8)

Still use use my trusty Casio fx451m solar/battery powered .bought in the early
80s for tech college , it's still going perfectly after 30 years of regular use !!.(I have only renewed the battery once in the 90's) . they really made em well .!!

fx100AU

I "grew up" programming my dad's TI59 (479 programming steps and 100 numbers stored!), moved to a Casio fx39 (fluorescent display  yeeees!) and then got a HP48SX that helped me through college. I then got a TI89 Platinum as a gift from a friend and my wife gave me her HP48GX after my SX died...
I also use a HP48 emulator on my phone, which runs faster than the 4MHz Saturn processor of the real deal. However, doing calculations on a real keyboard is a lot better.
Also, although the TI89 is an excellent calculator, once I got used to RPN it is hard to give up...

its best to use a PC so the outputs are fed into SPICE or other simulator
Hmm I need to learn to do that....

I have had practicaly every HP calculator from the 25 up to the 48Gx I stopped there because for my taste HP started going backwards after that point. I also have a free 48GX emulator on my laptop it is awesome! If I try to use a non RPN calculator I freeze and someone has to come over and reboot me.
If things get real ugly I use my sons student license of maple (Double awsome)
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=23328)

I have a TI89 Titanium, however I rarely use and will probably sell it very soon.
For my day to day work I use my computer, which is always with me anyway, and Matlab that works perfectly for simple and complex calculations.

A freebie i got at a fuel station. It has +, ,/,* mc mr m+ and square root.
If i need a bit more i have an HP20c so i can do log to do db calculations
It does hex calc also.
Anything more complex ? Not worth spending time on. Send it through the computer.

There is only one calculator designed specifically for electronics, the Casio FX61F:
(http://www.alternatezone.com/images/FX61F.jpg)
The end ;D
Dave.

LET THE CALCULATOR WARS BEGIN!! ;D

But other than that, yes, I use and recommend any preVPAM Casio algebraic.
The FX260 as mentioned (goes under other names in other regions) is I believe the only model Casio still makes that does not have VPAM.
It is also one of the smallest scientific calcs on the market.
Dave.

I still use, and LOVE, my TI86. I bought it about 10 years ago and it has never let me down yet. I also own a HP50g which i purchased because of all the rave reviews about it being a great calculator for engineers etc, but frankly, I think it is a piece of shit, and I will likely never use it again.
TI86 FTW!!!!!!!!!!!!!

Bought CASIO fx5800P back in the day because it could run COGO (coordinate geometry) programs in the field. Needless to say I never ever had to use COGO in anger but still love the 5800P and use it almost daily. Might steal those 27 formulas from Dave's and program them into mine but I doubt I'll use them either ::)
(http://edu.casio.com/products/program/fx5800p/images/fx5800p_image.jpg)

But other than that, yes, I use and recommend any preVPAM Casio algebraic.
The FX260 as mentioned (goes under other names in other regions) is I believe the only model Casio still makes that does not have VPAM.
It is also one of the smallest scientific calcs on the market.
Dave.
What's your take on V.P.A.M ?

What's your take on V.P.A.M ?
I don't like it, I find it annoying.
I was bought up on using a calc were you entered the number and then the operator, not the other way around (the newer "Visually Perfect Algebraic Method").
Dave.

Went for the fx83gt in the end, I quite like the look of the vpam tbh.
I must say as well, getting back into electronics at 40 ( after being into it as a kid ) really makes me wish I had paid more attention in maths, and also
just how beautiful it is ( never thought I would say that ! )
Jay

TI89. I have 2 and I use them both everyday. 1 at home and 1 at work.

I still swear by (not at) my trusty old HP16C.
Being of the old RPN only school of calculators I also have RealCalc installed on my Android phone.

My 20 years old HP 11C.
I have a scientific Casio in the lab (don't remember the model because I do not use it often: I don't like to use an = key, but this can open a debate, and I don't want this. ;)
My perfectly working (30 years old) HP 41C is into it's original box because batteries are no more available.
Best regards

I still swear by (not at) my trusty old HP16C.
Being of the old RPN only school of calculators I also have RealCalc installed on my Android phone.
I too have RealCalc , but sometimes i find it a little lacking since i have to shuffle between screens for the extra buttons .
I use a Sharp calculator i won't say which but it's utter bullshit , those cheap ones , that battery contactors get all gummed up after a year . ( At least i can equate properly )
But it's only because i don't know what calc to buy .

To place a bit of objectivity into selecting a suitable calculator, it's worth pointing out that young engineering students in the US looking to take the FE exam are limited to a small subset of NCEESapproved scientific calculators (http://www.ncees.org/Exams/Examday_policies/Calculator_policy.php).
I personally use a HP 35s almost exclusively, although I would like to own the not much older 32sii. I also own/use: HP 15c (x2), HP 33s, and HP 50g. It goes without saying that once you've made the transition to RPN, you'll never settle for anything else.
I've owned/used a handful of TI graphing calculators, starting with 86 and 83 in high school, then 84 Ag and 89 Ti in college. Got tired of lugging around a massive calculator whose powerful features weren't very useful.

Had a TI89 that died the night before my statistics exam. My flatmate had another one, so i was saved for that time.
Now i use HP 50g (excellent, except that the keys are a tad hard to press compared to what I'm used to) or the iPhone app m48 (free graphing HP48 emulator). Also have a Casio fx82ES for exams or when I don't need my HP.
Plan to get a couple of HP30b (cheap and seems to have good keys) and upgrade one of them to WP48 (scientific calc firmware). Check that project out, it's really cool!

I used a 23 year old CASIO fx570, but it has finally give up just last month (it also had the"0" key missing) :'(
I have been using RealCalc on my Tablet, but its just not the same.
I really miss being able to put in Engineering notations such a Mega, Kilo, micro pico, etc.
Modern calculators don't seem to have these short cuts now. ???
Maybe I'm just being lazy. :[

TI Voyage 200, TI30XS, TI30XA, Casio fx991MS.
Invariably, a 0.5mm Pentel Sharp Kerry and paper for some stuff.
I really miss being able to put in Engineering notations such a Mega, Kilo, micro pico, etc.
Modern calculators don't seem to have these short cuts now. ???
Casio fx991MS
Not really much of a short cut when compared to the the TI30XS which lacks this capability and yet takes five less key strokes to add something like 5 X 10E3 + 5 X 10E3 =
Like, 10 strokes to the Casio's 15.

To place a bit of objectivity into selecting a suitable calculator, it's worth pointing out that young engineering students in the US looking to take the FE exam are limited to a small subset of NCEESapproved scientific calculators (http://www.ncees.org/Exams/Examday_policies/Calculator_policy.php).
I've read the NCEES page, and I'm not sure that I fully understood:
They say that I cannot bring my trusty HP 11C to the exam, but I must buy that horriblelooking HP 33s?
Best regards

I really miss being able to put in Engineering notations such a Mega, Kilo, micro pico, etc.
See attached image.
I've read the NCEES page, and I'm not sure that I fully understood:
They say that I cannot bring my trusty HP 11C to the exam, but I must buy that horriblelooking HP 33s?
Best regards
The 11c hasn't been manufactured for decades. I suspect the new 15c may make the approved list for 2013.
P.S. You don't have to buy a 33s, although it was the most powerful option prior to the 35s being released. In fact, you aren't required to bring a calculator if you don't want to, but if you do, it must be one on the approved list.

Not really much of a short cut when compared to the the TI30XS which lacks this capability and yet takes five less key strokes to add something like 5 X 10E3 + 5 X 10E3 =
Like, 10 strokes to the Casio's 15.
[/quote]
???
Not sure I understand you buddy.
To input that sum in my old Casio fx570CD would take 8 strokes :P
ie:5 shift 5 + 5 shift 6 =

???
Not sure I understand you buddy.
To input that sum in my old Casio fx570CD would take 8 strokes :P
ie:5 shift 5 + 5 shift 6 =
The real question: is the output in engineering increments as well? If not, how easy would it be to display the output in engineering increments, if at all possible?

What's your take on V.P.A.M ?
I don't like it, I find it annoying.
I was bought up on using a calc were you entered the number and then the operator, not the other way around (the newer "Visually Perfect Algebraic Method").
Dave.
Likewise, I used to have a Casio FX82l. My sister lost that one for me.
Now I have a FX82GT PLUS with V.P.A.M. Although logical, it's still annoying. The older generation is used to using a calculator a certain way ;)

Although logical, it's still annoying.
I don't think "logical" is the right word. More like "convenient", especially to those who have little to no understanding of the actual mathematical operations invoked...it's a mindless copy/paste world these days.

???
Not sure I understand you buddy.
To input that sum in my old Casio fx570CD would take 8 strokes :P
ie:5 shift 5 + 5 shift 6 =
The real question: is the output in engineering increments as well? If not, how easy would it be to display the output in engineering increments, if at all possible?
If you mean can it give you the answer as 5.000005 K instead of 5000.005 then yes.
You can either make a further 2 strokes ie: MODE button followed by .
or as I normally do, put it into MODE . (this is ENG Mode on the FX570) before I start any engineering calculations.

If you mean can it give you the answer as 5.000005 K instead of 5000.005 then yes.
You can either make a further 2 strokes ie: MODE button followed by .
or as I normally do, put it into MODE . (this is ENG Mode on the FX570) before I start any engineering calculations.
It sounds like the sequence [MODE] [.] ranges the most significant digits of the output from 0 < output < 1000 and determines the appropriate symbol to concatenate on the display. How about manually changing the output between engineering increments, i.e. 0.005000005 M or 5000005 m?

I didn't know such existed, I would have bought one in a heart beat. I use the general scientific ones and later used the Sharp PC1 programmable to emulate what this Casio does. What a gem! Alas, no longer made.
What can be done now is using Android or iphones to emulate the FX 61. Current there are a slew of EE calculators, but they don't have all the right functions in one app.
For 30 years I carried an FX98 as my goto Casio until I found out it was rare, and losing it would be irreplaceable, if not terribly expensive. So several years ago, I loaded up on FX260s and leave the FX98 at home.
I last saw an FX98 sold on eBay for over $300.
(http://www.casiocalculator.com/Museum/Calculator/FX/FX98B/CasioFX98Bhold.jpg)
For Casionuts:
http://www.casiocalculator.com/Download/Collectors/CasioCollectors.html (http://www.casiocalculator.com/Download/Collectors/CasioCollectors.html)
But other than that, yes, I use and recommend any preVPAM Casio algebraic.
The FX260 as mentioned (goes under other names in other regions) is I believe the only model Casio still makes that does not have VPAM.
It is also one of the smallest scientific calcs on the market.
Dave.
There is only one calculator designed specifically for electronics, the Casio FX61F:
The end ;D
Dave.

Although logical, it's still annoying.
I don't think "logical" is the right word. More like "convenient", especially to those who have little to no understanding of the actual mathematical operations invoked...it's a mindless copy/paste world these days.
Yes, I agree, "convenient" is more the correct term. I did pause for a moment before choosing the word "logical", so yes, convenient is more the correct word. Thank you. :)

If you mean can it give you the answer as 5.000005 K instead of 5000.005 then yes.
You can either make a further 2 strokes ie: MODE button followed by .
or as I normally do, put it into MODE . (this is ENG Mode on the FX570) before I start any engineering calculations.
It sounds like the sequence [MODE] [.] ranges the most significant digits of the output from 0 < output < 1000 and determines the appropriate symbol to concatenate on the display. How about manually changing the output between engineering increments, i.e. 0.005000005 M or 5000005 m?
Sorry I don't follow you question.
If I was to put in 0.005000005 [shift] [7] and then [=] it would show 5.000005 K. note (key 7 being Meg)
and the same with 5000005 [shift] [5] [=] 5.000005 K. note (key 5 being milli)

(Almost?) all scientific calculators have an engineering mode that will make sure the exponent is always a multiple of 3, so 10,000 would be returned as 10 E+3. Is this really any harder to read than 10 k? I convert between k and 10^{3} without even thinking about it.
The only advantage of 10 k + 10 mili that I see is that it saves one keystroke compared to 10E3 + 10E3 (the units both being shift functions), since you don't have to type the minus. This might be a slight advantage if you often work with numbers < 1, eg. 10p + 1n  1000a.

casio fx  82.needs a clean under all the buttons mind.i cant do any math with a "3" in it until i clean it.three's are overated anyway imho ;D

Started with Casio way back, but then I discovered the HP11C, and haven't looked back since. Still use it daily, and picked up a 50g to replace a broken 48SX a few years ago (like to be able to see the stack + has units & unit conversions).

Speaking of Casio, i also have this marvelous "calculator": http://www.vintagesynth.com/casio/vl1.php (http://www.vintagesynth.com/casio/vl1.php)
The best about HP are their tutorials and manuals. They are fantastic.

For 30 years I carried an FX98 as my goto Casio until I found out it was rare, and losing it would be irreplaceable, if not terribly expensive. So several years ago, I loaded up on FX260s and leave the FX98 at home.
I last saw an FX98 sold on eBay for over $300.
For Casionuts:
http://www.casiocalculator.com/Download/Collectors/CasioCollectors.html (http://www.casiocalculator.com/Download/Collectors/CasioCollectors.html)
I sold my BROKEN Casio CFX400 scientific calculator watch for $400 cash to someone in the US before the whole ebay collecting craze took off.
That model is worth even more now, up into the 4 figures for a watch that I paid $20 for at KMart back in the 1980's.
Dave.

I think my first calculator was the Facit 1114J http://www.cs.ubc.ca/~hilpert/eec/calcpics/Facit1114J/view.jpg (http://www.cs.ubc.ca/~hilpert/eec/calcpics/Facit1114J/view.jpg)
I think i was still faster with my trusty Guessing Stick (Slide Rule for the young players), but it got me interested in the whole electronics / logic / computers field. The rest is history as they say :)

Not sure I understand you buddy.
To input that sum in my old Casio fx570CD would take 8 strokes :P
ie:5 shift 5 + 5 shift 6 =
Exactly. But they don't make that puppy any more. Which is a shame.

I started with a HP11c which is all I could afford in Uni, then on to a 32S and then a 32SII.
The lifespan of my calculators increased significantly after I stopped working as a Surveyor and my current calculator (my second HP32SII ) is now 20 years old and going as strong as ever.
One of the greatest advantages of RPN is when people ask to borrow your calculator :)

You guys are spoiled. Here's mine.
(http://upload.wikimedia.org/wikipedia/commons/e/ea/Boulier1.JPG)
j/k ;D
I have two dead TI graphing calculators, killed while going through engineering school: a TI86, and a TI89. By 'die' I mean their screens malfunctioned and the keypads became nonfunctional. One's screen died in the middle of my statics exam; I beat my fist against its face to get it to work, which made for a hell of a scene in the middle of a test, I assure you. I am probably the mostcareful person in the world with his electronic devices, so the fact that they died within two years of purchase really made me hate TI. How many years went by before they updated or replaced the TI86 or TI89 models? A decade? Ridiculous, especially given that the cost to the enduser almost never changed, yet the technology in parts used became ubiquitous, if not obsolete. It was almost as if TI refused to let the early1990s die. I found them to be nonintuitive, clunky, slow, inefficient (they go through batteries like a mofo), but worst of all they were required for a few classes.
That said, the best calculator I've ever used is my Casio from 1997ish. I'm away from home right now, so I can't look at it and tell you what the model number is exactly, but it has a threecolor screen, a teal case, and it's in the CFX9850 series. It looks much like this one, from the Wikipedia page:
(http://upload.wikimedia.org/wikipedia/en/thumb/2/2d/Casio_cfx9850gb_plus1.PNG/310pxCasio_cfx9850gb_plus1.PNG)
That was a great calculator, despite being a bit slow and REALLY hating cold weather. But the ubiquity of the TI units, and programs written specifically for engineering with it, pushed me to begrudgingly buy a refurbished TI89 Titanium. Happily it has held up well, but I keep it in a zipup padded case anyway. It seems to be much improved over the regular TI89, and I enjoy using it as long as I don't have to bust out the manual to finger out TI's silly coding and key sequences for operations.
My short list of most commonly used calculators is as follows:
1. Excel  much of what I do is done easiest with a spreadsheet and graphics
2. Win7 builtin calculator (whoever thought to make it do binary and hexadecimal, THANK YOU!)
3. My Android  there is some great calculator software out there now! I use Arity, RealCalc, TechCalc, and a couple others.
4. MATLAB
5. Mathematica
6. MathCAD
7. That TI89 Titanium

Sorry I don't follow you question.
If I was to put in 0.005000005 [shift] [7] and then [=] it would show 5.000005 K. note (key 7 being Meg)
and the same with 5000005 [shift] [5] [=] 5.000005 K. note (key 5 being milli)
For the HP 35s, 5.000005 K would be displayed as 5.000005e3. If I wanted to display this output in milliunits, I would press [<] [ENG >] once to display 5,000.005e0, and again [<] [ENG >] to display 5,000,005e3
So suppose you've just performed a calculation whose result is 5.000005 K. Now suppose you would like to easily determine what this number is in milliunits. Does the calculator have a dedicated feature for performing this task similar to the [ENG <] / [ENG >] f'n on the 35s?
I've noticed that the engineering mode for every calculator I've used would "auto range" the engineering exponent based on a coefficient which lies between 1 <= coefficient < 1000, e.g. an absolute result of 0.1234 would be displayed as 123.4e3, whereas an absolute result of 1.234 would be displayed unchanged.

OK, enough of these wimpy "calculators". Its time for the real men to step up and use one of these. Just two of my sliderule collection. I have 53 of different types. These two are specialty electronics rules.

One of the greatest advantages of RPN is when people ask to borrow your calculator :)
Hadn't really thought of that one as I haven't lent tools in years (too many things never returned), but good point. :D

OK, enough of these wimpy "calculators". Its time for the real men to step up and use one of these. Just two of my sliderule collection. I have 53 of different types. These two are specialty electronics rules.
Nice. I can only imagine the look on a professor's face if a student were to bust one of those out in the middle of an exam. :P

The Casio graphics calculators have a display mode for engineering notation using m/n/p/f/k/M/G, and a menu that lets you use the function keys/soft menu at bottom of display to enter them. I admit to using them if the maths I'm doing is all framed in terms of those units.

Sorry I don't follow you question.
If I was to put in 0.005000005 [shift] [7] and then [=] it would show 5.000005 K. note (key 7 being Meg)
and the same with 5000005 [shift] [5] [=] 5.000005 K. note (key 5 being milli)
For the HP 35s, 5.000005 K would be displayed as 5.000005e3. If I wanted to display this output in milliunits, I would press [<] [ENG >] once to display 5,000.005e0, and again [<] [ENG >] to display 5,000,005e3
So suppose you've just performed a calculation whose result is 5.000005 K. Now suppose you would like to easily determine what this number is in milliunits. Does the calculator have a dedicated feature for performing this task similar to the [ENG <] / [ENG >] f'n on the 35s?
I've noticed that the engineering mode for every calculator I've used would "auto range" the engineering exponent based on a coefficient which lies between 1 <= coefficient < 1000, e.g. an absolute result of 0.1234 would be displayed as 123.4e3, whereas an absolute result of 1.234 would be displayed unchanged.
If the answer is displayed as 5.000005 K then pressing [ENG] will give 5000.005, and again [ENG] will display 5000005 m.
I can also look at a display and understand, read the display as 5000005 03, but just find imputing into this type of calculator in ENGINEERING mode so simple and quick. 8)
I just need to try to fix the dam thing, as I miss it so much :'(

OK, enough of these wimpy "calculators". Its time for the real men to step up and use one of these. Just two of my sliderule collection. I have 53 of different types. These two are specialty electronics rules.
Nice. I can only imagine the look on a professor's face if a student were to bust one of those out in the middle of an exam. :P
This is exactly what rekindled my interest in mathematics :D I damn needed to learn how these worked, so found an emulator program, found a book and started slidin' right and left. As someone who was exposed to slide rules after being exposed to graphing calculators I might say that the slide rule is by far the most intuitive and most inspiring math tool of them all. Just for this reason alone it is worth learning how to use one.
Here is a free slide rule emulator. Thanks to the NZ guy who wrote it.
http://homepages.slingshot.co.nz/~timb3000/ (http://homepages.slingshot.co.nz/~timb3000/)
Here is a virtual Pickett N909ES Slide Rule
http://www.antiquark.com/sliderule/sim/n909es/virtualn909es.html (http://www.antiquark.com/sliderule/sim/n909es/virtualn909es.html)
(Hint: reverse the rule and try out the unit conversions ;))

This is exactly what rekindled my interest in mathematics :D I damn needed to learn how these worked, so found an emulator program, found a book and started slidin' right and left. As someone who was exposed to slide rules after being exposed to graphing calculators I might say that the slide rule is by far the most intuitive and most inspiring math tool of them all. Just for this reason alone it is worth learning how to use one.
You certainly can see the relationships in the calculations you are doing. With a calculator when you see an answer to 10 digits, it looks impressive and must be right with such accuracy. Except, you might have a result that is wrong to 10 digits!

HP 15C till my wife washed it. Dont ask

I use a somewhat battered Ti58, which works well enough ( but needs the keyboard stripped and cleaned) and have the odd HP and Casio around. TI is on permanently, running off a 3.6V supply as the batteries died and I did not get a charger when buying it at an auction.

HP15C  one at my desk, and one at the bench. Great form factor, and very resilient. Also useful: Python (with iPython / SciPy), Google, Wolfram Alpha

My calculators i use are the Casio FX992s which i got about 12 years ago, and the Texas Instruments TI83 Plus Graphic Calculator i bought about a year ago. I also have a program called Graph Viewer on my Nokia N86. (www.graphviewer.com (http://www.graphviewer.com)) which does advanced graphing of equations etc.

I have a TINspire graphing calculator. I don't really recommend it. It's not a terrible calculator but it's battery hungry and the display is hard to see. I have to hold it at a specific angle relative to the light just to read it.

I think the major advantage of a calculator should be that it lasts for ages on one set of batteries. And not take any time to turn on... Both of which the nspire fails at...

After I get first new HP calculator 25C, I have owned many different HP's but one is still in everyday use. It is 15C. I get it when it come to markets. (also I have many other models, some 34, 28S, SX,GX48 etc and also 71B with HPIB and disk drive, but this one 15C have been so handy that it have been this everyday "work horse" and it continue, I hope forever. Its keyboard work as dream. (today there is available some kind of cheap looks like copy but is really far away fron original guality. )
Of course one reson is RPN what keeps me married with HewlettPackard (exept that original HP company and all what was good have destroyed. It is true american shame how it may happend. Pity. )

The retards who designed the Nspire need to be fired with a quickness...all the button real estate at their disposal and not even the common courtesy to make the keypad a proper querty layout.

I use the TI59, TI30 and the SR50A. I just love the tiny LED displays in these things.
My first calculator was the Casio fx85s that I got for school, it still works on the first battery.

The retards who designed the Nspire need to be fired with a quickness...all the button real estate at their disposal and not even the common courtesy to make the keypad a proper querty layout.
Doubly puzzling considering they saw fit to extend that courtesy with the Voyage 200.

I know it's been mentioned but I can't fault my 991es plus, especially now I'm using almost all the buttons on it regularly :/

Doubly puzzling considering they saw fit to extend that courtesy with the Voyage 200.
I suspect the nonquerty layout is driven by the technicality of "computer" vs. "calculator" as applicable to testing; the inclusion of a querty keypad de facto classifies the device into the former category, rendering it an unauthorized device for many tests in the US...an uncritically retarded game of semantics if you ask me. :\

Well thanks to this thread I'm getting a Casio CFX9850G off ebay in a few days for use on that MIT 6.002x course. :) For the price of a pint of beer NIce. ;D

Well thanks to this thread I'm getting a Casio CFX9850G off ebay in a few days for use on that MIT 6.002x course. :) For the price of a pint of beer NIce. ;D
Oh, don't say that, I remember paying a hundredplus quid for mine shortly after it first came out  would've been towards the end of my days at secondary school, and working my way through my maths teacher's engineering maths textbook. Needed to replace my fx7000GB (which had suffered an indignity and ended up with a smashed screen) and figured "hey, shiny, colour screen and significantly more modern, what's not to like?"
Nice enough machine, the colour display is probably about the best you can expect given the technology of the time, and some of the features are rather nice  graphically solving inequalities makes good use of the colour, for instance  but I do sometimes have to spend a moment working out where in the menus a given option is hiding, compared to the rather upfront nature of its simpler brethren!
(Mind you, in more recent years I've picked up a replacement fx7000GB and an fx6300G, which I'd used before the 7000, both for very little; the 7000 lives on my desk at work whereas the 6300 hangs around the living room at home. The latter has been what I've been using for 6.002x; I was quite pleased to discover I could still remember how to use the graphics functions to read off values at an intersection, more than fifteen years after I last used that model in anger!)

I use KCalc on my computer (part of the KDE desktop). KCalc does binary, hex, octal, as well as decimal.
And I still use my HP15C, which I have had for twelve years. Got it secondhand. Still works great. I'd like to know if the ones for sale online are part of the original HP models, or if they're cheap Chinese copies. I'd buy another HP15C immediately if I knew it were made by HP.
I have also owned an HP41CX, which is a programmable calcu
lator. RPN is great for hand calculations, I agree. But it's
hard to read the programs when you write programs in it. What I mean is, to debug and to remember the HP41CX programs, I had to draw myself little schematics in order to remember what result was in which register before and after each step of the program and in which memories I had stored which intermediate results! Even with only a couple of registers, programs written for this machine were nowhere as easy to read as those written in a symbolic language, like Matlab, for example. I guess I might feel differently if I were an assembler programmer. But I am not.

Before reading this thread, I'd never heard of VPAM "Visually Perfect Algebraic Method". Does anybody know what is the difference between this and AOS "Algebraic operating system"?
Or is it just the same thing called X by manufacturer A and Y by manufacturer B?

I'd like to know if the ones for sale online are part of the original HP models, or if they're cheap Chinese copies. I'd buy another HP15C immediately if I knew it were made by HP.
The latest 15c Limited are manu. by Kinpo for HP. Battery life isn't as hot, the f'n buttons rattle, no reference on the back side, and diagnostics is different, but other than that, they're fair and worth the purchase imo. If you can pick up a good condition original for a comparable price (fat chance), I'd go for that over the new Limited.

I have a Casio fx3600P.
It is running on it second battery.
I bought it new around 1980.
Still works perfect.

VPAM is Casios term for having to write out the equation before doing calculations. Its geared towards learning math, but it can be very powerful if the calculators have more processing power, akin to solving complex equations like MathCad.
The cheapo style we first encountered, and comes in say the Windows calculator, is the immediate execution type, where each time you press an operator, the result is given, so if you have to work on complex equation, the user has to translate the math into how the calculator should do it. Its not a problem for 'basic' math like arithmetic, but move into calculus or where more variable are involved, and it get more tedious if not impossible.
http://en.wikipedia.org/wiki/Calculator_input_methods (http://en.wikipedia.org/wiki/Calculator_input_methods)
Before reading this thread, I'd never heard of VPAM "Visually Perfect Algebraic Method". Does anybody know what is the difference between this and AOS "Algebraic operating system"?
Or is it just the same thing called X by manufacturer A and Y by manufacturer B?

The best calculator is the no longer made HP 42s rpn calculator. I have it in a drawer and bought it 22 years ago for a lovely sum.
I love RPN, its so natural once you start using it.
Mine no longer works as one day I had a full sheet of mdf in the carport and various papers, straight edges etc on top as I was marking out. A friend of the wife arrived and drove up and parked on everything. I went out to find it under her bloody wheel.
A couple days later I went to ebay to find a replacement as they are no longer made. I couldn't find anything second hand under ~ $250 USD.!!
The manual is still a nostalgic read though :\

hp 48gx

Long ago, back before the Internet created HP collector insanity, when HP discontinued the HP42S, Walmart put them on sale for something like $15! I bought one, and now realize I should have bought all of them!
For me, I prefer the HP11c/15c, I think because the 11c was my first RPN calculator back in 1987. I've used it so long that it has shaped the way my brain works. It still has the original batteries :)
The best calculator is the no longer made HP 42s rpn calculator. I have it in a drawer and bought it 22 years ago for a lovely sum.
I love RPN, its so natural once you start using it.
Mine no longer works as one day I had a full sheet of mdf in the carport and various papers, straight edges etc on top as I was marking out. A friend of the wife arrived and drove up and parked on everything. I went out to find it under her bloody wheel.
A couple days later I went to ebay to find a replacement as they are no longer made. I couldn't find anything second hand under ~ $250 USD.!!
The manual is still a nostalgic read though :\

Me, I have an HP15C, more than 20 years old and still working.
Two things no one has talked:
1) RPN is easy to lean if you use the right approach:
always write first the number and after what "the number is doing" to the others you have already written.
Algebraic:
(3+2)*(52)
Slowly :
3 Enter the 3 is not doing nothing
2 + the 2 is to be added to the 3
5 Enter the five is doing nothing
2  the 2 is to be subtracted to the 5
* and the result will be multiplied
In RPN all in one line
3 Enter 2 + 5 Enter 2  *
2) What can this strange notation can bring as benefit?
All the new operands/routines that you define work the same as the "native" operands of the calculator.
Using // for the parallel of resistors lets calculate ( all in ohms!):
(((3+4)//(5+2))+3)//10
Two series of two resistors in parallel, then a fifth ( 3 Ohms ) in series and a sixth (10 Ohms) in parallel.
First the parallel can be programed in RPN as:
[Begin_Routine] 1/x x<>y 1/x + 1/x [End_Routine]
You only need 5 keystrokes and the [Begin_Routine] [End_Routine] stuff (specific to each calculator).
Now having assigned the Routine to an suitable key ( we will call it // ) to do the above calculation you will only need to press:
3 Enter 4 + 5 Enter 2 + // 3 + 10 //
Now, if you have an HP15C and want to do the same with complex numbers, you don't have to do nothing more.
Yes. What you have done, already works with complex numbers!
See, that's why some guys are mad about RPN.
So grab an RPN calculator emulator for your favorite OS and try it.
Greetings
paf

:o ti89 of course. I cannot imagine using anything other then a Ti89. They are truly a modern marvel.
Units? Check
Calculus made easy? Check
programs that deal with just about anything? check. Doing DSP stuff on a calculator is pretty cool.
Granted such things are not really necessary unless you are a student because there are computer programs and web apps that can out perform it. Having a calculus/algebra/differential equations/dsp/boolean logic portable device is undeniably neat... though I think the end of calculators is coming because of tablets which can perform all the functions with higher resolution/less cryptic programs.
I think the main problem with programmable calculators is the long learning curve, especially for user made programs. You have to read text files and remember commands, how to format stuff.. it would be much easier with a touchscreen gui.
Then again a calculator has the benefit of lasting a long time, being durable, having nice buttons. I would still prefer a ti89 tablet though. Though I suppose you might as well just run mathematica or maple on the tablet.

though I think the end of calculators is coming because of tablets which can perform all the functions with higher resolution/less cryptic programs.
One thing that all these tablets have in common is touch interface...which necessarily means that they all inherently lack one critical factor of the user experience: unique tactile feedback. As Johnny Lee has pointed out, we often neglect the probability of failure and its associated cost on the user experience when considering new glamorous technologies that popular consumer banter would suggest as a replacement for "the old way". Consider the damage caused by "iphone autocorrect". Now replace relatively harmless text messaging with calculating numbers; most people don't crunch numbers for a quick "lol".
Myth of the Dying Mouse (http://www.youtube.com/watch?v=kuhVfuhCcG4#ws)
P.S. I don't what it is about this presentation, but it never seems to get old.

I use my 50g :) and feel very weird using a non rpn one (have a 48 and 49g+ too, 49g+ of course is broken... due the bad quality of this series)
I really like how the new TI looks (the one with color screen and lion battery) and almost I buy one, hehe but I will keep my loyalty to hp ..... for now

I could understand the need for tactile feedback when you are crunching numbers doing accounting but running more complicated programs tends to be annoying... especially typing letters.

I could understand the need for tactile feedback when you are crunching numbers doing accounting but running more complicated programs tends to be annoying... especially typing letters.
As previously mentioned, one argument for why querty keypads are not as prevalent in calculators (as opposed to cell phones) is its reclassification from "calculator" to "computer". From a design perspective, firmware and a well thought out overlay would solve the typing letters problem, but the consequential impact on the majority target market (students and what tools are considered acceptable) would be adversely affected thanks to the established rules of play.
You'd have to clarify your definition of "complicated programs"; there's a very large gray area that encompasses what a device can do and what it ought to be used for. It goes without saying that with any design, a balanced compromise must be decided upon, and from a user perspective, I'm of the opinion that tactile feedback holds significantly greater weight than what popular consumer products have demoted it to...no doubt driven by the vogue of marketing forces. After all, a user may have to deal with "complicated programs" every once in a while, but interfacing is an anytimethedeviceispickedup affair.

I mostly use google calculator or matlab. Google calculator for its ability to do arithmetic on dimensioned quantities, and it is sufficient for 99% of cases where I would use anything resembling a handheld calculator. I use matlab for plotting, or for doing more complicated math/programming.
I do have a calculator on my phone which I use as a last resort.
For hand held calculators I used to love my HP48GX, but I haven't used it in ages.

As another posted said, the scientific calculator is dying, if not already dead, IMHO. Its primary use in my observation, is education. VPAM, graphing etc., are mostly for novice users, which is currently the target market for calculators.
The key issue is after you make a calculation, what do you do with the result? Integrate it into another program for further processing? Enter the result in field, in a computer? So, for the most part, calculators today for professional use are mostly for back of envelope brainstorms, and quick approximations, rather than for precision work.
Even in the simplest use, debt or mortgage calculations, actual results by banks use very high precision numbers, 230x more than a general scientific calculator. However when sitting down with the bank agent, they are opt to use a calculator to give the customer a ballpark figure. Often a feature of a specific 'financial calculator' is they do have higher precision numbers compared to a general scientific or programmable one [ 1632 bit numbers in financial, versus 10 or 11 digits in the Casio FX260] or present the amortization table on a PC their working with, again making the calculator superfluous.
So, in the end, the modern scientific calculator is more like the slide rule was before 1980, to make estimates, but instead of breaking out the log or trig tables and extending the precision, we punt it to computers instead.
RealCalc puts a scientific calculator on my Android phone, and I use it about as much as my FX260, but the cramped screen makes it less attractive to reach for. Its main appeal is it works very much like the FX260.

TI89 Titanium. I wish I had gone for just the regular ti83 looking back.

So, in the end, the modern scientific calculator is more like the slide rule was before 1980, to make estimates...
I hope you'll excuse me for raising an eyebrow when a NIST engineer speaks of numerical "estimates". :P

Even in the simplest use, debt or mortgage calculations, actual results by banks use very high precision numbers, 230x more than a general scientific calculator.
This is actually a myth propagated by financial types who don't understand math. Financial transactions are rounded to the nearest penny, and intermediate values in a financial calculation will be rounded aggressively at every step along the way. A double precision float has an effective 53 bit significand, more than enough dynamic range for financial calculations on any scale smaller than the GDP of a G8 country.
The problem is simply that (binary) floating point arithmetic of any precision is unsuitable for financial transactions because certain values are not representable. You can't represent $0.10 exactly in as floating point number. When written in base 2, the number 1/10 is an infinitely repeating fraction, so it can't be captured exactly with any finite width number.
The upshot of this is that if I transfer $0.10 to your bank account, and our balances are represented as floating point numbers, the total amount of money before and after the transaction is not constant. This is obviously bad!
So financial calculations must be done either with integers (representing cents), or decimal (BCD) representations. It isn't that the financial type necessarily has more resolution, it simply has the specific type of rounding behaviour required for financial transactions.

So financial calculations must be done either with integers (representing cents), or decimal (BCD) representations.
Learn something new everyday. I suppose that would explain the BCDencoded registers in older HP CPU architectures (http://www.hpmuseum.org/techcpu.htm).
Are there any handheld calculators that actually use doubleprecision floats?
EDIT: Evidently, a few Sharp querty handhelds fit the bill...doesn't seem to be many without diving into the userspace realm.

Sometimes from metrology labs, 'estimates' could refer to uncertainty in the LSD presented, not so much from the calculation, but the actual measurements 99.99% confidence interval, and thus estimates are good only to so many digits.
I hope you'll excuse me for raising an eyebrow when a NIST engineer speaks of numerical "estimates". :P
Rounding errors make more sense, I stand corrected. However, if more digits were used in the calculation the rounding error can be masked, once rounded to a penny, but that may be too much to expect of lower cost hand held calculator.
For example, for financial transactions try this simple mortgage table:
200000 (1 + 0.06/360)^(360*30)
Casio scientifics have a small rounding issue, as seen in the FX260 and other models, it returns 1209747.95.
The right answer is 1209748.04, which can be done with higher precision calculators or better rounding.
Not a big deal for 9c difference, unless your a hacker stealing 9c from millions of accounts ;)
Even in the simplest use, debt or mortgage calculations, actual results by banks use very high precision numbers, 230x more than a general scientific calculator.
This is actually a myth propagated by financial types who don't understand math. Financial transactions are rounded to the nearest penny, and intermediate values in a financial calculation will be rounded aggressively at every step along the way. ...

For example, for financial transactions try this simple mortgage table:
200000 (1 + 0.06/360)^(360*30)
Casio scientifics have a small rounding issue, as seen in the FX260 and other models, it returns 1209747.95.
The right answer is 1209748.04, which can be done with higher precision calculators or better rounding.
Interesting  the Casios have obviously gone backwards sometime since the mid80s/early90s, then! Just tried that on my fx7000GB and got 1209748.042; doing it in Fix2 mode also gives 1209748.04.

To be precise, my own calculator based on rational numbers (http://home.arcor.de/0xdeadbeef/Calcutta.htm) says the answer is
1209748.03722963021023976099764994429324362344006195944401452964332492379118987483444215101643363697513166243909463144784174311993772628
:)

This depends upon what type of mathematics you are doing and how small you want it. It is a complicated question, because there are so many options and choices that were not available a few years ago. You could have a complete calculator with an app software for an I Pod touch or I pad or Android telephone or tablet. I use a Casio fx10cg (20cg outside of North America. It is a back lit color LCD display graphing calculator, very large. On the small is a common solar cell TI30sx, just numerics. I have an HP Kinpo made HP49G+. I like the color one more. I have an old TI92 with the Motorola 68000 CMOS processor inside it. It is an 16 years old math ship, too big to be a calculator. I like the TI Nspire CAS CX in color, but I already have a color Casio, so no need.

Yes, it affects only the generation of FX that look like the FX260. Here is a 'family' photo spanning 30 years.
Once in the VPAM or graphing Casios, that error is not there.
The left is the FX100 that I used in college in the late 1970s. The lower right is the credit card FX98, which is nearly identical to the 100 except its 8 digits, and thus, rounds out the same error. Finally on the right is the modern Fx260.
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=23534;image)
For example, for financial transactions try this simple mortgage table:
200000 (1 + 0.06/360)^(360*30)
Casio scientifics have a small rounding issue, as seen in the FX260 and other models, it returns 1209747.95.
The right answer is 1209748.04, which can be done with higher precision calculators or better rounding.
Interesting  the Casios have obviously gone backwards sometime since the mid80s/early90s, then! Just tried that on my fx7000GB and got 1209748.042; doing it in Fix2 mode also gives 1209748.04.

So financial calculations must be done either with integers (representing cents), or decimal (BCD) representations.
Learn something new everyday. I suppose that would explain the BCDencoded registers in older HP CPU architectures (http://www.hpmuseum.org/techcpu.htm).
Are there any handheld calculators that actually use doubleprecision floats?
EDIT: Evidently, a few Sharp querty handhelds fit the bill...doesn't seem to be many without diving into the userspace realm.
As far as I know, all HP calculators use BCD binary internally. The modern calculators using ARM processors(or whatever they use) are running emulators of the older HP calculator processor chips which are all based around BCD registers.
Richard.

Yes, it affects only the generation of FX that look like the FX260. Here is a 'family' photo spanning 30 years.
Once in the VPAM or graphing Casios, that error is not there.
Yes, I just grabbed my other two and tried the same thing; the fx6300G (early90s 'baby graphic', newer than the one I tried at work) gives exactly the rounding error you mentioned, 1209747.95, whereas the CFX9850G (mid90s colour 'power graphic') gives the correct (to displayed resolution) 1209748.037.
I wish I knew where the 'just a normal scientific calculator' fx85M and fx85V models I remember using as a kiddie had got to, would be interesting to try it on them too...
I guess it goes to show how valuable it can be to characterise your tools, to work out what level of precision you can depend upon!

Casio fx5800P displays 1209748.037
SpeedCrunch which I use instead of windows calculator displays 1209748.037229630210239761
SpeedCrunch is highly recommended btw.

Yes, since all calculators have to round in the end, the more digits or bits it uses to represent a digit, the less likely the rounding error will appear. Of course, some algorithms are worse than others depending on how they round and what they round.
I recall some calculatornuts did benchmark testing using formulas designed to 'expose' these types of errors, see here and enjoy!
http://www.rskey.org/~mwsebastian/miscprj/forensics.htm (http://www.rskey.org/~mwsebastian/miscprj/forensics.htm)
http://voidware.com/calcs/torturetest.htm (http://voidware.com/calcs/torturetest.htm)
Casio fx5800P displays 1209748.037
SpeedCrunch which I use instead of windows calculator displays 1209748.037229630210239761
SpeedCrunch is highly recommended btw.

The problem is simply that (binary) floating point arithmetic of any precision is unsuitable for financial transactions because certain values are not representable. You can't represent $0.10 exactly in as floating point number. When written in base 2, the number 1/10 is an infinitely repeating fraction, so it can't be captured exactly with any finite width number.
This argument is entirely bogus. How do you represent $10/3 exactly in BCD? It's just as impossible as representing $0.10 in binary.
It doesn't matter, you argue? Well what happens with interest calculations? Suppose you need to add 5.7% per annum to a balance on a monthly basis. Are you going to do that precisely in BCD? Not a chance!
Ultimately the only way to get decently accurate answers is to use enough extra digits of precision (and careful arrangement of calculation order) so that rounding errors are insignificant. It ultimately makes no difference whether you do that in BCD or in binary. The results will be identical.
For instance, this is what my (binary) calculator says about 200000 * (1 + 0.06/360)^(360*30): 1209748.03723
Apparently binary arithmetic works.

This argument is entirely bogus. How do you represent $10/3 exactly in BCD? It's just as impossible as representing $0.10 in binary.
Undoubtedly, eliminating error altogether is unrealistic, but that doesn't mean that the effort is futile. If it can be eliminated for select common cases, wouldn't it make sense, budget permitting, to design a system that has the potential to minimize compounded sources of error, viz. which has higher propensity for error: 16decimal BCD or 16bit binary? Seems to be the philosophy back in the day; in the case of HP, investing in a custom ASIC for their lineup was justified. Not so much the case today, where relatively formidable computational power is ubiquitous and quad precision can be had with little effort.

On a side note here is something that I wasn't aware of until recently. A NOVA film from 1985 about some of the more intricate and controversial aspects of mathematics.
For over a decade, Bertrand Russell tried to find a certainty through mathematics by reducing it to logic. In his massive work, Principia Mathematica, it took him 362 pages to prove that 1 + 1 = 2
Twenty years later, another mathematician, Kurt GÃ¶del, proved that mathematics would never be completely certain.
What does the last sentence even mean?
Horizon A Mathematical Mystery Tour (http://www.youtube.com/watch?v=PUDQ3ypFhew#)
Now if a video from 1985 starts with rolling on the screen
Fermat's Last Theorem
The Goldbach's Conjecture
The Riemann Hypothesis
Classification Problem for 4D Manifolds
P?NP Problem
Invariant Subspace Problem for Hilbert Spaces
then you know it is about some serious stuff. But do these even matter? To me they do matter, in a certain way. They form a benchmark. If they don't matter for what I'm doing then I'm not doing something terribly fundamental or important, gives a sense of scale so to speak.
Some of the things presented here you may have heard before, but I for example was not aware of the Bertrand Russel's paradox of catalogues and metacatalogues. It is also very interesting how mathematics can find out its own mistakes and limitations without external reference.
also check out here for a summary and some more clues
http://faculty.etsu.edu/gardnerr/MathMysteryTour/mathematicalMysteryTour.htm (http://faculty.etsu.edu/gardnerr/MathMysteryTour/mathematicalMysteryTour.htm)

Twenty years later, another mathematician, Kurt GÃ¶del, proved that mathematics would never be completely certain.
What does the last sentence even mean?
Maybe you already know this, but it means there are some true statements in any system of logic that cannot be proven.
It comes from the idea that mathematicians had, that mathematics, being a pure system of abstract thought separated from reality, was one place where you could achieve a notion of certainty, where you could say "this statement is true and I can prove it so" for all true statements. GÃ¶del showed that is was impossible, that you could never achieve such a thing. There will always be statements that are true, but which nevertheless cannot be proven to be true. Mathematics will always be incomplete.

Maybe you already know this, but it means there are some true statements in any system of logic that cannot be proven.
It comes from the idea that mathematicians had, that mathematics, being a pure system of abstract thought separated from reality, was one place where you could achieve a notion of certainty, where you could say "this statement is true and I can prove it so" for all true statements. GÃ¶del showed that is was impossible, that you could never achieve such a thing. There will always be statements that are true, but which nevertheless cannot be proven to be true. Mathematics will always be incomplete.
It is funny how casually we talk about it. The guy went on and made certain that certainty is unmakable and we talk about it as if it was just a matter of putting in the manhours.

On a side note here is something that I wasn't aware of until recently. A NOVA film from 1985 about some of the more intricate and controversial aspects of mathematics.
That video was fun. Thanks for indirectly coercing me into burning away an hour of productivity. :P

That video was fun. Thanks for indirectly coercing me into burning away an hour of productivity. :P
What do you mean,
Burning away an hour in order to produce productivity, or
Burning away productivity in order to produce an hour? ;D

The problem is simply that (binary) floating point arithmetic of any precision is unsuitable for financial transactions because certain values are not representable. You can't represent $0.10 exactly in as floating point number. When written in base 2, the number 1/10 is an infinitely repeating fraction, so it can't be captured exactly with any finite width number.
This argument is entirely bogus. How do you represent $10/3 exactly in BCD? It's just as impossible as representing $0.10 in binary.
It doesn't matter, you argue? Well what happens with interest calculations? Suppose you need to add 5.7% per annum to a balance on a monthly basis. Are you going to do that precisely in BCD? Not a chance!
Ultimately the only way to get decently accurate answers is to use enough extra digits of precision (and careful arrangement of calculation order) so that rounding errors are insignificant. It ultimately makes no difference whether you do that in BCD or in binary. The results will be identical.
For instance, this is what my (binary) calculator says about 200000 * (1 + 0.06/360)^(360*30): 1209748.03723
Apparently binary arithmetic works.
The problem is with floating point arithmetic using binary representation, not with binary arithmetic. It is certainly an issue. IEEE floating point can't represent the most basic of numbers in base 10 with decent precision.
Most languages, if you do something like provide 2.35, will convert to floating point, and then when displayed back you will get 2.3500000000000001. There are lots of examples of this on the internet.
Normally the biggest issue isn't the accumulation of errors as numbers grow, but the fact they rarely cancel out. You end up with tiny balances of 0.000000000000001.
BCD means that the errors you see are the same as with base 10 systems. 0.1 = 0.1. 1/3 = 0.3333333333. You can accurately represent any two decimal place number in BCD, but not with floating point.

This argument is entirely bogus. How do you represent $10/3 exactly in BCD? It's just as impossible as representing $0.10 in binary.
That is true, but irrelevant. You never make a transaction of $10/3, but you do make transactions of $.10. You can't have 3 1/3 dollars in your bank account. If you buy oranges 3/$1, one costs $.33, not $.33333. Two cost $.67. If you buy one today and come back for one tomorrow, they each cost $.33  you don't still owe the merchant an ephemeral third of a penny.
It doesn't matter, you argue? Well what happens with interest calculations? Suppose you need to add 5.7% per annum to a balance on a monthly basis. Are you going to do that precisely in BCD? Not a chance!
At every compounding period, you round the interest to the nearest penny. Something you can't do if the balance is represented as dollars in floating point.
Ultimately the only way to get decently accurate answers is to use enough extra digits of precision (and careful arrangement of calculation order) so that rounding errors are
My point, which you completely missed, is that financial calculations do not need extreme accuracy in the sense that scientists and engineers are used to. They need a specifically defined behavior which can only be accomplished through the use of integer or BCD arithmetic and correct coding.
insignificant. It ultimately makes no difference whether you do that in BCD or in binary. The results will be identical.
No, they wont.
For instance, this is what my (binary) calculator says about 200000 * (1 + 0.06/360)^(360*30): 1209748.03723
Unfortunately, that is wrong. Well, you have correctly calculated the given expression to the desired precision, but that is not the answer you get if you deposit $200,000 in a bank account with 6% interest compounded daily for 30 years of 360 days (!). The answer to that question would be the recurrence relation:
x_0 = 200,000
y_n = x_{n1} * (0.06/360)
x_n = x_{n1} + y_n
Where x_n is the balance on the nth day, and y_n is the interest payment on the nth day, which should be rounded to the penny. This is the only way that your balance (and the bank's balance which isn't shown) are legal values at the end of every day.
The end result is: $1,209,748.66  although I am still not 100% sure I got the rounding correct (round to nearest with ties going to the even number) since I was using integer arithmetic. You end up with a bit more than if you solve the the entire problem with high precision and then round at the end, because for the specific values chosen you happen to win a few more times than you lose on the rounded penny.

I just tried some of these tests:
http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/msg106609/#msg106609 (http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/msg106609/#msg106609)
On freeware RealCalc on Android. Its >= to my Casios, and its free.

Here's my list of emu's and calcs :
Droid48 (HP48 RPN)
MobiCalc (Cube Calc)
RealCalc
Scientific Calculator
Andie Graph ( TI86 ROM installed )
Graph 89 with TI89 v2.05 ROM installed

To be precise, my own calculator based on rational numbers (http://home.arcor.de/0xdeadbeef/Calcutta.htm) says the answer is
1209748.03722963021023976099764994429324362344006195944401452964332492379118987483444215101643363697513166243909463144784174311993772628
:)
I thought I better check your calculations are correct  there are a few digits there that just look wrong.
Here is my Sinclair Scientific after calculating (1 + 0.06/360):
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=23610)
Now the rest of the calculation:
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=23612)
Before you get too tough on my Sinclair Scientific, when this came out, there was only the HP35 at 1/5th the cost of a new VW beetle and the HP45 was a bargain if you had just won the lottery.
The Sinclair was brilliant compared to a slide rule or log tables. And it was sold as a kit! You built it yourself, and when it didn't work, Clive would replace it with a working one for a bit under 3 British Pounds.
Unfortunately for Sinclair, HP and TI started bringing out excellent programmable scientific calculators the next year that were more affordable then the HP35, making my Sinclair Scientific obsolete.
Clive Sinclair took an early 70's TI 9 digit calculator chip designed for x / +  fixed point calculations only and crammed a 5 digit resolution floating point RPN calculator in the same mask ROM space. Notice how there is no equal/enter key or decimal point key  who needs them anyway? Don't need exponentials either when you have a perfectly good log/antilog function.
Richard

Mostly my HP28S and (when it is feeling in the mood) Casio FX3600P.
(http://i222.photobucket.com/albums/dd237/Zadpics/IMG_2537.jpg)
Oh, and the one in my profile pic :D
Actually no, not that one, the CFX200 in that condition is worth way too much to wear regularly. It only comes out for special geek occasions.
I wrote a blog article nearly a year ago on the subject of modern calculators and how useless they are. 12 months on and I still haven't bought a new one! http://electronicsdesigner.blogspot.co.uk/2011/05/difficultcalculations.html (http://electronicsdesigner.blogspot.co.uk/2011/05/difficultcalculations.html)

55378008
Really? ::)

;D
I took the photo for the Pistonheads forum. What can I say, it is all about cars. People often claim to have things that aren't actually theirs (to put it in context, there are people there who do own interesting metal like XJ220s, F40s, McLaren F1 etc) and someone calls for a Custard Test. Originally this involved getting a tin of Birds custard in the same shot as the car which the author claims to be theirs.
e.g. http://img444.imageshack.us/img444/1222/12072007080dr4.jpg (http://img444.imageshack.us/img444/1222/12072007080dr4.jpg)
More recently they have had:
Jason Plato (British Touring Car Championship winner) http://images.pistonheads.com/nimg/23419/Plato%20custard_1L.jpg (http://images.pistonheads.com/nimg/23419/Plato%20custard_1L.jpg)
Chris Harris (journo and owner of a fleet of Porsches) http://thumbsnap.com/eJdsqIcS (http://thumbsnap.com/eJdsqIcS)
Jason even got custard into a Porsche 911 review on Channel 5 TV. In my case, Custard Test was called, and that was the request. Yes of course it's childish. I'm too old to grow up now.

I love this thread. Like many of you I have a deep (strange) love for calculators. I read Zads blog post and it resonated with me quite a bit, so while I was doing other things last night I thought about my own calculator experience. I had a TI89 for most of college and loved it. I also used Matlab a lot, like many of you. I realized that I used my TI89 entirely for hand calculations, but never used it's programability. I rarely used Matlab for those sort of hand calculations, and when I did 90% of the time they ended up morphing into a program. I largely credit this to the power of Matlab, the ease of entering data, and also the ease of graphing the results. I'd often end up with a dozen graphs.
However I hate the time investment in starting it up, and a laptop burns a lot of power doing things that aren't making my computations. Generally this isn't an issue for the desk which is why I think the calculator market is in trouble.
What I really wanted to know, and I think will give us more insight into what calculator we use and why we hate newer ones, is what we actually use calculators (of all forms including Matlab) for these days. I work in embedded design and software, and I rarely use a calculator these days. My main applications are simple math for footprint dimensions and converting numbers between variable bases. What about everyone else?

Mine makes a great shop spaceheater also.
Wang Series 300 NixieTube Calculator (http://www.youtube.com/watch?v=1nWQd5SPtAI#)

What I really wanted to know, and I think will give us more insight into what calculator we use and why we hate newer ones, is what we actually use calculators (of all forms including Matlab) for these days. I work in embedded design and software, and I rarely use a calculator these days. My main applications are simple math for footprint dimensions and converting numbers between variable bases. What about everyone else?
What I do most these days is playing with graphs. Below for example is a constant power source giving 10W (red trace) and a Thevenin source of 2V in series with 10 Ohm resistor (green). By playing with sliders I can see how they behave. In this instance there is 4.14 Volts between nodes and 2.41 A flowing trough the circuit.
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=23640;image)
Hard to do this with hardware calculators so I've been going through many pieces of software lately. So far the big CAS packages that I tried needed scripting to do this  they are powerful but scripting is not my thing really. Small programs seem more practical and this is one of the better ones so far. It comes with the much despised (and probably rightly so) TInspire. Unfortunately it is not good enough to be worth the quarter of the price they ask for it, so after the trial period is over back to open source CAS packages it is. Now, if some brilliant chap decides to write a good practical GUI for Maxima that would be super super awesome, just sayin'.

Not sure if a CAS is really what you need. Later versions of Maple offer a GUI for example, but clicking on a function and selecting 'solve for x' only takes you so far. You will need to type commands for the advanced functions that make people spend serious money for these packages. Plotting simple functions is not exactly their target market. It's not going to be any cheaper than the TI software either. Sounds like you rather need a good interactive plotting application. Not sure what to recommend, since I tend to focus on the CAS side.
MathStudio (http://mathstudio.net) might do what you want, it makes it relatively easy to add scroll bars to graphs (Scroll(variable,start,end,step)), and is much cheaper than many of the other commercial packages. Of the opensource packages, Sage (http://sagemath.org/) can do interactive graphs, but this involves some scripting.

Not sure if a CAS is really what you need. Later versions of Maple offer a GUI for example, but clicking on a function and selecting 'solve for x' only takes you so far. You will need to type commands for the advanced functions that make people spend serious money for these packages. Plotting simple functions is not exactly their target market. It's not going to be any cheaper than the TI software either. Sounds like you rather need a good interactive plotting application. Not sure what to recommend, since I tend to focus on the CAS side.
MathStudio (http://mathstudio.net) might do what you want, it makes it relatively easy to add scroll bars to graphs (Scroll(variable,start,end,step)), and is much cheaper than many of the other commercial packages. Of the opensource packages, Sage (http://sagemath.org/) can do interactive graphs, but this involves some scripting.
Thank you alm, as helpful as always. I have tried Mathematica as well as most open source software except Sage which I can not run because I am tied to a win machine due to solidworks, the single piece of code that ties me to windows. Sage can be run with an emulator of course but it is just too clumsy that way, not really worth it for me, might be better for somebody who actually knows what he is doing.
Math studio seems nice and is remarkably similar to what the creators of SpeedCrunch anounced they want to achieve, and honestly if I am paying money I much rather donate it to open source people.
One software that is open source and has a nice user interface is GeoGebra which makes use of Maxima code. Currenly geared mostly towards school geometry and some graphing. Perhaps they are the closest team to achieve a well rounded business like graphical interface.
Mathemathica and the TI program above share one good feature  the ability to create documents with inline interactive math and graphing. A most useful feature if you wanted to create a math heavy document describing, say, propagation delay in PCB traces. TI's program shoots itself in the foot by not being open source, Mathematica less so because they provide a free player at least.
With the advent of the MathMl and free CAS programs the open source community is uniquely situated to make such a document format and spread it widely. I can think of at least 50 such documents for everyday electronics work alone.

Sage can mix HTML (and Latex) with math and graphing, although I'm not sure if I would use it for long/complex documents. One issue is publishing: since the Sage engine is not exactly lightweight, you can't access some features (like interactive graphs) when serving the documents to the public. You can only access these features if you're logged in, and I would be surprised if there weren't any security issues with providing random strangers with a login since you essentially have access to a full Python interpreter. There may be a PDF/HTML export option for static documents, I've never looked for it. It does have its own 'publish' feature, but that requires running Sage on a server accessible to the recipients.
There is also sagetex, which makes it possible to call Sage and include the results within a Latex document. This would probably be the closest to what you want, and much better for complex documents than the toy word processor that Mathematica and Maple provide.
I believe Sage is by far the closest thing to an OSS Mathematica/Maple clone. Too bad Windows support is limited to nonexistent.

Local solver is a must of course. Even if security is disregarded we can not always depend on availability of a server and 99% of the work is trivial anyway.
On a side note, I wonder what can be done using an analog computer linked to a CAS.
Recently red this presentation (http://www.cs.indiana.edu/~jwmills/EAC.ppt.htm) about analog computers solving protein folding problems. Apparently there is still some research on the topic. The interesting bit is that it uses three dimensional bulk resistor networks consisting of conductive fluid. It also works realtime (as do all analog computers I believe).

Now here is exactly what I want my calculator to do (just arrived in YT)
Exploration of the Aplitude and Phase: First Order Applet (http://www.youtube.com/watch?v=JNsNgXKFgdo#)
I want to be able to create this kind of documents using a GUI without having to write code. I also want to be able to use/modify documents created by other people and perhaps have a library covering all the topics I am interested in.

I have a couple of Sharp EL9300 graphics, but I mainly use an old Casio fx5500L "Scientific Library" for the basen features.
It does 32 bit binary, and it's really fast to use for conversions between dec, hex and bin.
Are there any more modern scientific calcs with 32bit binary?

Calculators are helpful to me because it works faster than on a PC, or my Android phone. Ergonomics play a large factor. However, once the data set I'm using goes over 10+, or I'm using paper to track portions of calculations, it time to move to a PC, it also justifies the setup time.
I get to use most of the functions on my FX260, as I've had with all its ancestors. Some more than others.
There are USB calculators than allow you to pass the data sets to PCs. But they charge far more than an FX260,tend to be large, you'd have to justify its cost on the frequency of use. Basic USB calculator keypads alone cost more than many scientific calculators.
Smartphone, iPad or equivalent could be the final death knell for professional use of calculators. A suitably well written app would then have the same form as a calculator but far larger, with beeps and vibrations compensating for the lack of physical switches. I find the iPad form suitable to replace my FX260, but the true size of the FX260, weight, cost, portability and robustness still wins out, so my FX260 is alive and well. But, when I'm on the road and KISS is important, I use my RealCalc Android calculator instead of lugging yet another item.
I had a TI89 for most of college and loved it. I also used Matlab a lot, like many of you. I realized that I used my TI89 entirely for hand calculations, but never used it's programability.
Generally this isn't an issue for the desk which is why I think the calculator market is in trouble.
What I really wanted to know, and I think will give us more insight into what calculator we use and why we hate newer ones, is what we actually use calculators (of all forms including Matlab) for these days. I work in embedded design and software, and I rarely use a calculator these days. My main applications are simple math for footprint dimensions and converting numbers between variable bases. What about everyone else?

Here is the calculator I use.
Reasons I like it:
1. Full size keyboard for fast entry
2. Can copy and paste values to/from other applications
3. Rapid recall and editing of previous expressions with up arrow key
4. Convenient use of named variables
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=23647;image)

Here is the calculator I use.
What is that? Looks very Matlablike without all the bloat.

What is that? Looks very Matlablike without all the bloat.
I wrote it for my own use. It has just enough features to meet my needs with, as you say, no bloat. I strongly dislike bloatware.

I wrote it for my own use. It has just enough features to meet my needs with, as you say, no bloat. I strongly dislike bloatware.
Haha you would. ;D I need to stop thinking like a consumer and start thinking like a proper engineer.

I have two TI36X. One at my computer and one at my metal lathe and milling machine. Does the job. But I'm considering getting one of the new HP15C to try out RPN.

I have two TI36X.
Ooh. I like the look of that calculator. Simple, functional, solar powered, no algebraic logic crap. I'm gonna get one. I don't need one, but what the heck...
I have one of the new HP15c calculators. It is nice, and enormously powerful. It can do linear algebra, and complex arithmetic, and linear algebra with complex numbers (!), and it is programmable. Unfortunately there seems to be a bit of a keypad lottery. Many people find a defective key or two that doesn't quite work right. On mine it is the sin key. Do you really want the hassle of returning it for a replacement that might, or might not, be an improvement? Apart from that it is a nice calculator.

The new TI36X is different. You can probably check it out at Target and such. The ones I have are the old version. Black...The color calculators should be. :)
You can get the old ones on eBay for under $10. It only does 8bit binary, just so you know.

I have the new TI36x...the so called "Pro" version. Why on earth do manufacturers tack "Pro" on the product name...it seems precisely like the sort of silly thing one would resort to if you intended to sell rubbish to naive consumers.
Anyway, it is a pretty fair calculator for those times you need something with more moxy than your average calculator but not necessarily the raw processing power, and subsequently more complex interface, of the top flight HP or TI graphing machines.
I'd say it probably does what you most often need a scientific calculator to do and manages to keep the interface fairly fast and accessible.
And, it's black. So you just know it's for "serious users". :)

Abybody use one of these?
I admit I blew my annual toy budget on this, but it is a magnificent mechanism

The new TI36X is different. You can probably check it out at Target and such. The ones I have are the old version. Black...The color calculators should be. :)
You can get the old ones on eBay for under $10. It only does 8bit binary, just so you know.
Turns out I already have a TI30XA. I thought it looked familiar. No need to buy another I suppose.

I still have my TI Programmer II , and still use it
(http://www.datamath.org/Sci/Slanted/Images/TIProgrammerII.jpg)
Else i use this HP 50G (that also have AOS (TI), i dont like RPN)
(http://h10003.www1.hp.com/digmedialib/prodimg/lowres/c00725137.jpg)
But now i also use the "Standard" Ubuntu calculator in Programming mode
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=23725)
/Bingo

Although the picture is not my exact calculator, this is my calculator none the less. Notice the electronic specific keys for resistors in parallel "//" impedance "z" capacitor and inductor keys. it even has 27 specific electronic formulae. As I am at work I do not have the manual with me and it was and still is a great calculator.

I use the Casio fx82MS for a long time.
(http://images.bidorbuy.co.za/user_images/140/435140_081221125933_FX82MS.jpg)

Although the picture is not my exact calculator, this is my calculator none the less. Notice the electronic specific keys for resistors in parallel "//" impedance "z" capacitor and inductor keys. it even has 27 specific electronic formulae. As I am at work I do not have the manual with me and it was and still is a great calculator.
Really wish casio made such a calculator again

(http://images03.olx.cl/ui/11/53/88/1311296624_221874588_1FotosdeCalculadoragraficaCasioCFX9850G.jpg)

Sorry to dredge this one up again but I found this neat calculator. You guys are probably all familiar with it, but I like it. I think I'm going to buy it. It even does pico/nano/micro etc etc. so you don't mess them up...like me. One day I swear, I'm going to be working on some big project and bodge up the conversion factor. Well anyway..
http://www.sharpusa.com/ForBusiness/SmallElectronics/Calculators/EL506XBWH.aspx (http://www.sharpusa.com/ForBusiness/SmallElectronics/Calculators/EL506XBWH.aspx)
(http://www.sharpusa.com/~/media/Images/Home/ForHome/HomeOffice/Calculators/Products/EL506XBWH/EL506XWH.ashx?w=745&h=445&bc=ffffff)

Looks nice!
I used a HP11c for years,until I inadvertently put it,& my car keys in my back pocket at the same timegoodbye display!. :(
I now use a HP22s which I picked up secondhand,but it isn't as powerful,& doesn't use RPNAAAARRRRGGGHHH! >:(

Looks nice!
I used a HP11c for years,until I inadvertently put it,& my car keys in my back pocket at the same timegoodbye display!. :(
I now use a HP22s which I picked up secondhand,but it isn't as powerful,& doesn't use RPNAAAARRRRGGGHHH! >:(
If it doesn't use RPN it is illogical ;D

Oh stop you sound like the dinosaurs at my brothers work who always bust my brother guts for using a Ti83. ;D
If it get's the job done easily enough, I'm not sure why it matters. I've used RPN only once. It's okay. Just have to get used to it.

At school, we've had a ti82 stats (pretty much a ti 83). Very powerful device, many teachers and students only used a fraction of it's features.
After I read about RPN and the HP48 series, I purchased a HP 50g. I think it's one of the most featurepacked calculators ever made. Which other calc does FFT and calculations with units? Although, it is kinda sluggish. Some time later, I got the 15C LE. I use the one which is in best reach. Once I got used to RPN, using a "dumb" calculator (no algebraic entry) has become real hard.

I'm not a fan on stack based calculations (RPN) because I like to be able to see the whole equation on one line before I hit ENTER (or =). It is also easier to edit equation in single line entry, although it is quite a bit easier to enter equations using RPN than it is using standard algebreic entry.
However, modern TI calculators don't use this method... they use "Pretty Print" (or something like that, which basically means you can enter an equation exactly as you would on paper. There is no longer a need for excessive brackets. The devisor is placed underneath the dividend, exponents are displayed as superscripts, symbols are displayed instead of functions (square root sign instead of "sqrt(...)"), and you can you the up and down arrows to navigate between the different layers of the equation, instead of just left and right.
Entering complicated equations in my TI Nspire CX CAS is MUCH easier than entering them into my HP 50g. However, it is easier to enter equations in my HP 50g using the RPN mode than it is to enter those equations using its algebreic mode.

i always use the TI86 on my phone and ... i'll just say i find it very hard to use a normal scientific calculator anymore
The TINspire CX CAS is really nice for what it does and the price is right.

My TI86 (bought in 2006) lost a few lines on the display. I "resoldered" the LCD cable (just heated it with a hot air gun and hoped for the best) and it works like a charm. While I'm not happy that the thing was hideously overpriced and broke down in five years, I still love TI because of their sample policy.
I've also got a TI 30XA in the lab. I spilled some juice on it the very day I bought it.

For me it's HP all the way! I've been using HP since my first calculator back in the early '70s.
In fact, the only time I've ever used a nonRPN calculator is when borrowing something from someone to do a quick calculation when I didn't have one of my HPs at hand.

HP35S always in RPN mode and my most used and two casio Fxsomething. Besides that two slide rules 8)
I would love to have an electonics sliderule (and the one HP made for VNA use in the early seventys)

Which other calc does FFT and calculations with units?
I know my TI89 Titanium does, and many others should too.

HP35S always in RPN mode...
Manager type borrows the 35s sitting on my desk to do a quick itinerary calculation, then returns it shortly thereafter due to his inability to locate the = button. That was earlier today.
Prognosis: Wielded by the ignoramus, RPN calculators tend to cause spontaneous scalp itching.

I still use my 48GX and have a virtual one on my Laptop. I got a 50G for my son and in my opinion they ruined it.

I own many pocket calculators, but it is a long time since I have used any of them. Somehow they seem to have become obsolete...
I hate this conclusion since I loved calculators in my youth, but they no longer seem to have any value outside of exams.

I mostly use a TI89 Titanium, modded with charging over USB.
http://www.eevblog.com/forum/productreviewsphotosanddiscussion/teardownti89titanium/ (http://www.eevblog.com/forum/productreviewsphotosanddiscussion/teardownti89titanium/)
55378008
Really? ::)
https://lkml.org/lkml/2012/7/13/154 (https://lkml.org/lkml/2012/7/13/154)

My name is Ken. I have a calculator problem.
I use a HP 32S at work, HP 34C at my desk, and HP 15C at my lab bench. I love them all but generally recommend the 15C for those benighted souls who have yet to discover why HP zealots are sold on RPN. Because I've used it longer than the others, the 34C has a special place in my heart, but the "1/x" key (used frequently in RPN operations) is a shift function, which makes it harder to use than it should be. The 15C gets it right in all the important places. The longdiscontinued 32S has base conversions, which are great for software work.
Aside from the 15C, the current HP RPN offerings are problematic. The 35S has its charms (fractions, for example), but the display resolution is so coarse I find it hard to read, the format is too big and clumsy, and I still can't forgive HP for making "STO" a shift function. The 50g is a fascinating machine that I would choose for an eternity of solitude on a desert island, but it's a dreadful calculator for almost all practical purposes. (I will also admit to a small collection of "antique" HP calculators, but I don't use them as my daily beaters...)
I have explored HP calculator apps on my iPhone, too. My favorite is "VintageRPN", which includes an emulation of the original 35 and 80, arguably the most usable and inspired HP calculators of all time. And once again, they are highly usable, even on the tiny touch display of the iPhone.

I have the HP48 TI89 and TI86 on my phone ... oh no

15C gets it right in all the important places.
Except for perhaps a keypad layout with a bias towards righthanded people.
...I still can't forgive HP for making "STO" a shift function. The 50g is a fascinating machine that I would choose for an eternity of solitude on a desert island, but it's a dreadful calculator for almost all practical purposes.
Not as unforgivable as their handling of binary and hex. Complex number handling could be improved too. I'd probably use my 50g more often if it had a proper plastic cover like TI graphing calcs; I'm too chicken shit to lug it around in my backpack out of fear of damaging the crap the screen from all the random trinkets tumbling around, and its leather pouch is just retarded IMO.

I'd probably use my 50g more often if it had a proper plastic cover like TI graphing calcs; I'm too chicken shit to lug it around in my backpack out of fear of damaging the crap the screen from all the random trinkets tumbling around, and its leather pouch is just retarded IMO.
It's not a hard case, but you might want to look at Ripoffs (IIRC, the CO29 fits the 50g; dimensions look right, and the image matches what I have). Dense foam sandwiched between nylon, so it's thick and does protect rather well, so it will do what you want. Only a very small area of the top sides is even exposed (say 3/4"x1" where the flap folds over). BTW, you get 2 layers of case over most of the the screen when the flap is folded over.
Not in school anymore, but I'm clumsy, so I bought one of these to protect it from myself. :P
http://www.ripoffs.com/datasheets/co29/co29.html (http://www.ripoffs.com/datasheets/co29/co29.html)

I use two calculators. A TI83+ silver edition and a TI89 Titanium.
For calculations that are exceedingly large, long and difficult, I use Mathematica. One example is the Park's Transform. That transform and it's inverse are used to simplify the control of 3 phase AC motors. The output equations are pretty terrible, yet a powerful Digital Signal Controller (DSC) are able to use them to drive the motor.

I like calculators with real, lightup VF displays. My favorite is an old Sharp EL500 scientific calculator. It has a weird placement of the "0" key, but otherwise it's almost perfect.
My circay2k TI82 sits on the shelf, in case I need it.

Well im pretty sure you cant buy one as new anymore. What i use i mean... HP 48GX, its more then 10 years old, but does job nicely. Programmable, has rs232 serialsport (needs adapter cable)... And if i really want to go old then my trusty old Sharp PCE220 programmable calculator. Both are older then i care to admit, but still work perfectly.
Advise for you? Go any decent store and you can buy reasonable calculator there, expecially if your willing to buy one of those scientific ones...

I use a simple scientific calculator: M228 nata by Milan
(http://www.milan.es/skin/default.aspx?ACCIO=PORTALENC&NIVELL=6579D32CB08575F91C1EA6F6AC4B01478AD9B84B5717D6AC270A430A636BBCAD653C00745F544981461BA740A92CDC9B41C6EC135D5A86E8 (http://www.milan.es/skin/default.aspx?ACCIO=PORTALENC&NIVELL=6579D32CB08575F91C1EA6F6AC4B01478AD9B84B5717D6AC270A430A636BBCAD653C00745F544981461BA740A92CDC9B41C6EC135D5A86E8)).
It cost me only 8 USD.
I am pretty happy with it :)

i use my calculator that i got for school. its a Texas instruments TI30XB scientific calculator, i think it costs 30 or forty Aussie dollars. it does all that i need.

Various tasks require various calculators! I don't think it is universal. For example I have three calculators and they are all used semiregularly.
Texas Instruments TI30Xa Calculator (used for basic calculations on bench or classes which don't permit graphing calculators)
Texas Instruments TINSpire CAS CX (used in some of my advanced math classes)
Texas Instruments TI92+ (used generally on my electronics bench when working more complex formulas. generally doesn't go to classes anymore
Late (Dead/Gone/Missing):
Texas Instruments TI83+ SE
Alright I didn't even realize I am biased towards TI... not intentional just get either what is commented by professors or what other classmates are getting (why I now have the nspire).

TI92, vintage. This thing still works! ;D

I use the HP15C I got a tad over 28 years ago :P

I use a TI89 Titanium and a HP 50g.

I use a Casio FX115MS, because it's one of the very few models that understands and supports engineering suffixes for powers of 10. So, for example, I can directly multiply 47n by 33.1k and get an answer of 1.5557m, without having to first think about converting the natural way I write and specify components into E9 or E+3 or whatever. Stick the calculator in Eng mode and it gives results directly in picofarads, megahertz or whatever other unit is appropriate, not just x.yyyE13 which requires thinking.

After the hint from juiceking about calcultor apps I found a very nice app from a HP45s for my lumia 900
I allready used it a lot. It looks so rela, and because the 900 is a big phone it works great too. I was using it on my desk and one of the guys asked, " got a new calculator ? , nice, looks expensive" he did not noticed it was my phone.
Also found one for the ipad, from a HP42. This is a real woking picture of a 42 (but with added functions) as an extra it gives the stack and registers seperate in a box. It works well but i think the modern two line display showing X an Y stack at the same time is more usable, aso the fact it uses rectangulair and polar notation on one line instead of R in Y and jX in X ( or I do domething wrong) . ( but not as good looking as the leds)
I would love to have on old HP with the pointled display. But i think they are rare collectors items by now (and need a lot of batteries)
Fred

a more recent fx82AU mainly becuase it has a rather deep memory and its functionality covers effectivly my understanding of mathmatical formula, (i am one of those people that become confused with integral representations of plain algebraic equations)

Does the HP 45 emulation include the "secret" stopwatch feature? Does it keep lousy time like the real thing?
There are always plenty of the old LEDbased HP calculators on eBay, and when I was interested in these things I noticed that occasionally buyers made out like bandits when there was a dearth of bidders on a common model in mediocre condition. The original batteries are inevitably shot, but there is a vendor on eBay who thoughtfully supplies new nicads in the right shape as a replacement. Leaked batteries are these old calculators' worst enemies, so insist on seeing an interior photo before bidding.
There are some very detailed and interesting papers from HP about the workings and engineering of the original 35 and 80, and on YouTube, a superb interview of Tom Osborne.
You are warned that reading these papers may create an irresistible desire for one of these in your hand,
After the hint from juiceking about calcultor apps I found a very nice app from a HP45s for my lumia 900
I would love to have on old HP with the pointled display. But i think they are rare collectors items by now (and need a lot of batteries)
Fred

Yes, it has the hidden timer and you can choose someting that as to do with original speed or time or so bu I did not know what they meant because I have no compare.
I never buy or look on ebay, this is as selfprotection ( i allready have to much gear and I can not make bids, if someone askes no price on the dutch craigslist equivalent i do not react, even if i want the instrument) i have one GR bridge from ebay but a friend negotiated and bought if for me.
I will look the osborn movie. There is a piece about the 35 in an interview with hewlett or pachard, they ask in a meeting about is if this could be commercial because the price and Hewlett said something like ; if there is a computer I can take with me in my pocket I would buy it, and i I would there must be others. They named it calculator because a computer was in those thays synonim with IBM.

Yes, it has the hidden timer and you can choose someting that as to do with original speed or time or so bu I did not know what they meant because I have no compare.
Original speed means the calculations will take as long as they did on the original calcualtor running its painfully slow processor. Otherwise they happen instantaneously

Some emulators i used actually emulate the calculator so well it feels like the original processor's and ram's in :\
Well at least the TI86 emu i have didn't emulate the processor either, only the 96KB

The TI86 is the best calculator ever made in my opinion.

My first calculator was HP 21 back in 1975, once I got my head around RPN it was amazing what you can do with 4 level stack. Nowadays I don't use calculator very often, I got HP 32SII for more demanding tasks and for casual use I got Real Calc on my phone (in RPN mode of course). I find after getting comfortable with RPN I can use algebraic entry calculator but it requires extra effort and it's slower for me.
Got a bit of soft spot for old calculators, mainly HP but other too. Have a few HP 21's and some others from 1970's, most of them bought junk from Ebay and restored to working order. There are few more waiting to be repaired including Casio from early 70's (4 function office calculator with VFD display) and abused HP 28S which may be beyond restoration.

In my progression from the hp25 to the hp48GX (and every single model between them) I used to carry my hp97 to work every day in my breifcase. Magnetic card reader to load programs, soft keys that lined up with the magnetic card, built in thermal printer, pure calcualtor porn. ;D
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=29076)
I still use the 48GX every day in the shop. I hate the 50, it is unuseable compared to the 48.

Nice, do you use the paper tape feature? Can you still get inkedribbon for it? I see they occassionally sell them but its nearly $45 for a ribbon cartridge!
http://www.staples.com/HP97TricolorInkCartridgeC9363WN/product_573985 (http://www.staples.com/HP97TricolorInkCartridgeC9363WN/product_573985)
In my progression from the hp25 to the hp48GX (and every single model between them) I used to carry my hp97 to work every day in my breifcase. ..

I did not keep all the intermediate calculators, I sold them to friends and coleagues as soon as I could buy the next generation. The printer on the 97 was thermal. I actualy wrote a 97 program that generated gcode for our cnc lathes before there were readily available CAM packages. I had 3 people using the same program on hp41CX's cranking out gcode to manualy punch into the controls. Also did a program to do helical interpolation before it existed as a command on the cnc controls. Many a thread was milled using that program. Those were the days ;D

I still use the 48GX every day in the shop. I hate the 50, it is unuseable compared to the 48.
I have been considering buying a 50. Could you please elaborate on your experience with it compared to the 48?

I have been considering buying a 50. Could you please elaborate on your experience with it compared to the 48?
It could be that it is just harder to get to the things I use a lot and I didn't give it much of a chance ( got very frustraded very quickly). Unit conversions on the 48 are very convienient with very few keystrokes. There are to many levels of menu for me on the 50 to get to the conversions and even when yoy get there it is not as useable. If I didn't have years of conditioning on the 48 I might find the 50 ok. I am not adverse to agebraic entry since I use maple for heavier duty stuff but it is to cumbersome for daily number crunching in the shop. (I know the 50 does RPN also but I still dont like it)

Looked for an old HP on the Dutch market place but not much offers, just one and that was sold the same day for over 55 euro. That is more expensive as a new 35s
What would be a good model for EE , must have complex numbers.

Looked for an old HP on the Dutch market place but not much offers, just one and that was sold the same day for over 55 euro. That is more expensive as a new 35s
What would be a good model for EE , must have complex numbers.
That might be a tough combination... The classics don't have native handling of complex numbers. You can program the HP65/67 for this, but then you are looking at more money and the hassles of programming and magnetic cards. The HP67 bizarrely puts shift functions UNDER the keys (not over them, as on every other HP calculator) which makes them annoying to use and error prone. Both models depended on the battery to be in the calculator for voltage regulation...it's a common problem that the card reader motor is damaged because someone tried to use the calculator with the external power adapter without a battery in place.
The HP34C is a late LED model with nonvolatile memory, and no doubt can be programmed to do some complex number operations. These are not that rare, but their weak point is a fragile battery cover, so watch for problems there. (Also, I will repeat my complaint that the reciprocal key is a shift function, which is terrible because reciprocal is a commonly used operation in RPN.)
I think you would like the HP 15C very much, even though it doesn't have an LED display. The LCD has very good contrast and is readable under normal light. The newer dotmatrix LCD displays on HP calculators are very hard to read by comparison. It has good complex number support built in, and achieves its power without ruining usability. The old ones are collector items, but HP reissued this model as a "limited edition" and they were selling until recently on the HP website for about $100. Maybe they ran out, but they are still available on Amazon, I believe, for about the same amount.

Thanks for the info.I think I keep using the virtual one for fun. I had not tought about batteries ect. I really want to use it and I have the 35S that I like but I want that in the shop instead of the casio (and it is in a safe leather jacket) and a second HP for my "desk" (i do the design ect not in my lab but most times while resting on bed or couch.
So I looked for the 15C and that is indeed very nice. I think I have to get used to the single line display but the functions are placed very logical. Found one here in Holland. On stock 115 euro and free postage.
Let you know when I have it.

I have an HP35S and I am impressed with it. it does everything except graphing and is in the traditional design that HP was known for. Well it doesn't have the double molded keys but the feel and colours are very ergonomic.
There is an open source project based on the HP20/30 that is also very interesting.
This person is selling a premodified product at what I think is a reasonable price for his time:
http://commerce.hpcalc.org/34s.php (http://commerce.hpcalc.org/34s.php)
There are also links to the project.
For the most part I use the emulators for HP calcs on my Samsung Galaxy SII, but still like the physical feel of real HP calcs.

I found an open source emulator that works under linux of a HP15C. Installed is yesterday on my pc instead of the standard calculator. I am on my Ipad now so i cannot link it but if you search for HP15C emulator you find it. It looks just like the real on.

I have an HP 35s.
Bought it 3 years ago. I was quite new to RPN back then but quickly learnt it and fell in love with it.
It replaced my old Casio FX83MS. Now, whenever I get the old Casio out I forget how to use it.
My only major complaint about the 35s is the display, it isn't very readable in the dark. I wonder how easy it would be to bodge in a backlight.

HP42S, along with an ancient Casio FX602P. most commonly though are the real simple ones in the cellphone, or the built in scientific one in Debian gCalctool. More often then not a pen and paper is sufficient.

My HP15C limitted edition just arrived. I love it. The 35s can do more, but the 15C does all functions I use too, but is a bit easier to use. Also a very clear display.

Using caculator in my Galaxy II, haha ;)

I used to use a HP20S with was some of the most advanced we where allowed to use in high school back in 92. Still have it and it is rock solid. I upgraded to a texas TI89 titanium when I started on my engineering degree a few years ago..

(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=29633)

a strange looking TI85

I use a Casio FX115MS, because it's one of the very few models that understands and supports engineering suffixes for powers of 10. So, for example, I can directly multiply 47n by 33.1k and get an answer of 1.5557m, without having to first think about converting the natural way I write and specify components into E9 or E+3 or whatever. Stick the calculator in Eng mode and it gives results directly in picofarads, megahertz or whatever other unit is appropriate, not just x.yyyE13 which requires thinking.
Just got my Sharp W516X. Just like yours. It has an Eng Mode which allows you to flip between I believe, Tera, Giga, Mega, Kilo, milli, micro, nano, pico, and of course the widely used...femto.
Also has an entire library of scientific constants ranging from mass of an proton, to plancks constant, to faradays constant. Also has a metric converter between certain measurements, not everything unfortunatley, but the more used ones. Like *C to F*, gallons to liters, etc.
It also converts to/from Hexdecimal, Binary and a slew of other Nbases.
The editor is really nice. If I have a rather complicated equation that I would like to solve, on my previous calculator (TI 30XII) which is about $5 cheaper than my Sharp, I would have to fudge around with a ton of parenthesis and then get those wrong and it get's aggrevating. "WriteView" editor works really well on this.
Like holy hell, every time I read the user manual, I find something else.
I have only two gripes about this calculator. One is that this new version of the Sharp 516 has a really glossy black panel.. And the keys are the same color as the front panel. If I was sharp I would have made the number keys perhaps a gray and then certain function keys a different color. Again, it is still very usable. Just sometimes it makes it tricky to find the key you want.
The other gripe is that the default answers are in simplest fractional form. There is a button called "Change" which cycles through mixed number, fraction, and decimal. However, if you change the mode to Stat it defaults to decimal. Again, not a huge problem. It's not terrible but it does take 2 button hits to get a decimal number.
Otherwise, huge amount of functionality, which is to be expected nowadays, but thumbs up to Sharp.
I really like it.
I wish I could take it apart just to look at it, but i appears Sharp has hermetically sealed the case in addition to using like 8 screws. The calculator is one of the lightest calculators I've ever used, which is why I want to take it apart. It feels...yes...a bit cheap, but it's not flexible at all. Doesn't bend or stress, so I'm intrigued a bit.
The only reason I want to take it apart is because my TI30XII was the dodgiest POS I've ever seen internally. Bodge jumper wires...and to make things more disgusting, they had made provision to use surface mount components in about 5 places, according to their foot print, but TI of course cheaped the hell out. They decided to instead of getting a 22uF ceramic 0805, to use a POS through hole electrolytic and solder it onto the pads. Same thing with two LEDs they had in there...for whatever reason...debugging perhaps? Crystal was soldered on the same way. Yuck. I didn't even want to own it after that..If you are literally producing millions of these calculators, I really don't understand how having some poor guy solder on some through hold components onto SMD pads is more economical. You buy probably in quantity 1,000,000 at a time. The price difference has to be so tiny...But perhaps the Sharp is the same way. I'm going to try to take it apart again...

Thru college I thought I needed the hp 48SX, especially for statics/dynamics and difeq's. Oddly, the better I got at math, the less I needed it. After a while all I ever needed was a cheap ass walmart calculator(Casio fx260 to be exact) that has trig functions, logs, and a few other bits and pieces. And the older I'm getting the more calculator averse I'm becoming. When you think about it, NASA put three guys on the moon with a damn slide rule! So if you start thinking you need some huge feature laden calculator, you might be mistaken. LOL

Partially agree, though I do not have close to the amount of experience as you do... I'm not saying that everyone should be walking around with a TI89, but the nice thing about modern calculators is that they can really help you eliminate stupid mathematical errors, and can help you do problems more quickly and more accurately. That's not to say that you can't do that with a slide rule, of course, but modern calculators help us to have confidence in the results we get. For example, one thing I like about my calculator is that I can write the equation in as it would look on paper. I can't tell you the amount of times where a missed parenthesis has changed my result completely. Of course that is just user error, but as humans we are capable of mistakes. We are also capable of catching those mistakes, but it's nice when we don't have to do that.
Just a thought.

The only reason i look to more expensive calcs is simply : I hate cheap scientific calculators, they go intermittent within a year and can give you funny calculations even when they battery's fresh

HP 67 all the way!
Works like new.
Fixed the magnetic card reader.
A pleasure to write programs with.

Dad had the later model with LCD display........ and the card reader, the expanded memory blocks and a few roms as well with overlays.

Yes, the HP41C...got that one too, but still prefer the sturdy all in one HP67.

Best calculator ever.
HP 48gx
http://en.wikipedia.org/wiki/HP48_series (http://en.wikipedia.org/wiki/HP48_series)
Currently getting by with.
HP 49g
http://en.wikipedia.org/wiki/HP49_series (http://en.wikipedia.org/wiki/HP49_series)
Considering replacing it with.
HP 50g

Sounds like a good topic to post my first post to.
I got a hp 48gII for cheap some years ago. Not to be confused with real, original, 48series calculators, this one is a less powerful version of the 49series. The keypad feels nice, but the buttons break too easily. I've had two buttons break already. The buttons still engage, but the plastic supports are broken, so the buttons are "wobbly". Also too big and heavy for everyday use.
My everyday calculator these days is a HP 32SII. Small and lightweight, feels durable and has just enough features. If I need more computing power I look for a compter anyways.

Best calculator ever.
HP 48gx
I still use mine and I also have this emulator on my laptop that works great. 49 and 50 stink in my opinion.
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=30591)

49 and 50 stink in my opinion.
I agree the 49 stinks. I definitely miss my 48. But I've heard the 50 is marginally better than the 49.

I have a ipad app of a 48. But it has to many functions. I have not found a manual yet but it is rather complicated. After a week i managed to get the solve function to work and that is a realy great function. My 35S and 15C also have solve but the 48 is more easy. You see the vars, go with the cursor to the one you want to know, press solve and ready. Real cool.

I have not found a manual yet but it is rather complicated. After a week i managed to get the solve function to work and that is a realy great function.
Manuals here http://h10025.www1.hp.com/ewfrf/wc/manualCategory?cc=us&lc=en&dlc=en&document=&product=58443 (http://h10025.www1.hp.com/ewfrf/wc/manualCategory?cc=us&lc=en&dlc=en&document=&product=58443)
Solver is great in that you only have to enter the equation in one form it will rewrite the equation for all the other variables. Multiple equation solver is even greater. You can store multiple equations that share some variables. It shows all the variables in one solver and then searches for whatever equations it needs and solves for intermediate values necessary and spits out the variable you solved for.
The equation library is an example of this. Go to ohms law in the equation library and you will see how it behaves.

Might I ask where you get the 48GX emulation program?
Miss using my old 48SX (still have it, but a couple of lines on the display are shot, and the way it's sealed <melted/welded plastic pins>, I'm afraid I wouldn't be able to get it back together if I managed to repair/replace the screen). Have a 50g, but it's not the same feel (more of an empty plastic enclosure that will break vs. 48 series). The 50g also loves to eat batteries.

Might I ask where you get the 48GX emulation program?
Free :) http://hp.giesselink.com/emu48.htm (http://hp.giesselink.com/emu48.htm)

Might I ask where you get the 48GX emulation program?
Free :) http://hp.giesselink.com/emu48.htm (http://hp.giesselink.com/emu48.htm)
Thankyou. :)

My new fave!! 8)
http://www.eevblog.com/forum/productreviewsphotosanddiscussion/questionhowcandollartreesellascientificcalculatorforadolar/ (http://www.eevblog.com/forum/productreviewsphotosanddiscussion/questionhowcandollartreesellascientificcalculatorforadolar/)

I have an HP42S but that reminds me working with an ASIC company in China a few years ago left me with an interesting item: a cheap looking (like this one (http://img.tjskl.org.cn/pic/z198576f0x01/credit_card_calculator_credit_card_calculatoritem_no_kk_842further_details842_jpg.jpg)) ostensibly fourfunction calculator that had trig functions and was actually programmable, the extra features accessed via multikey combinations (not printed on the case). The concept didn't really catch on.

CASIO College FX100A been using since 1980,
just also acquired CASIO FX82a plus

(http://www.pa4tim.nl/wpcontent/uploads/2012/11/hp9100B_1.jpg)
Not mine, its on my bench for restaration only
This one is mine since Yesterday. Made in 1971 week 43 according to the serialnumber. A HP 35 the mother of all scientific pocket multimeters
(http://www.pa4tim.nl/wpcontent/uploads/2012/11/hp35.jpg)

What do you guys think about the new OLED color graphing calcs by makers like TI (nSpire) and Casio (Prizm)?
I think they look rather gimmicky, but I've never actually used one. I'd assume battery life must be atrocious. I really like my current calculator (Sharp EL516X) because it has dual power (solar + battery). Never have to change the batteries in my calculator again.
I wonder if there's any use for eink in calculators? Might be interesting.
Anyway, any thoughts on those smartphones with calculator software running on top calculators?

I can choose between a sharp PC1211 and a 1500. During my study my uncle boreed me his Sharp and I think it was a 1211. But hat was around 1983 or 1984 so I'm not sure.
The man I'm repairing the 9100 for has both and I can get one. I think the 1500 is more practical because it has more possibilitys and uses regular AA batterys ( they are both with the printer)
( i'm afraid calculators are like multimeters, they multiply. Allready have 3 HPs and 2 casio's and a bunch of HP apps. Think I would like a HP65 42 and 48 but then its enough, ( something tells me this oes the wrong way. ;) )

This one is mine since Yesterday. Made in 1971 week 43 according to the serialnumber. A HP 35 the mother of all scientific pocket multimeters
(http://www.pa4tim.nl/wpcontent/uploads/2012/11/hp35.jpg)
thats exactly what you need! 99% of everything you'll do can be done with that calculator, and none of the really useful functions are buried beneath three layers of shift and mode keys. When it comes right down to it, everything else is just window dressing. All the stuff you need is just right there at your fingertips. Brilliant functional product design. The only thing I might add in would be a few brackets for nested calculations, degree radian and gradient modes, and engineering mode just because occasionally I like to be lazy.

What do you guys think about the new OLED color graphing calcs by makers like TI (nSpire) and Casio (Prizm)?
I think they look rather gimmicky, but I've never actually used one. I'd assume battery life must be atrocious. I really like my current calculator (Sharp EL516X) because it has dual power (solar + battery). Never have to change the batteries in my calculator again.
I wonder if there's any use for eink in calculators? Might be interesting.
Anyway, any thoughts on those smartphones with calculator software running on top calculators?
I got both a Ti nspire touch (B/W) and the CAS colour version..
and they are truly great, i would say the most advanced and best calculator in the world today! They are truly enormously powerfull..
You can have 4 windows (yes like on the PC) at the same time and it multitasks simultaiusly between them.
TI claims this new color version will last 2 weeks between charges if you use them on daily bases.
Just watch the video.. i just cant start to say how great it is. The CAS version is just a mini PC.. and with them you get a software version of the calculator for your PC.
Texas Instruments Nspire CX Colour Graphing Calculator (http://www.youtube.com/watch?v=0uosNiJPiik#)
3D sphere TINspire CX (http://www.youtube.com/watch?v=VVHJTSRu1TU#ws)
And its Vernier function lab equipment connection, with sensors, (yes even voltmeter) is just great for data collection. but they "cost a little".
DOOM and gameboy games also run on them !!
So my old 30 years CASIO FX720P is resting now.. but that is also a truley great calculator (Basic programin language).

But as far as usability? I mean sure it's powerful, but do you think yo make any sacrifices using one of those?

The only thing I might add in would be a few brackets for nested calculations...
Brackets wouldn't be needed as it uses RPNthere is a stack for nested calculations built in.

Wow, I wasn't aware that those originals were RPN calculators. Thought it was just the 35s models. I stand corrected.

A couple months ago "RealCalc Plus" from Android Market was on sale for something like 25 cents (free version is more than good enough but the offer was too good to pass). I showed it to a fried, he installs it on a (big screen) Galaxy Note and then shows it to his wife. Wife thinks it's a calculator and start "hey, when you bought that?"

I have a 42S app on my Nokia lumia and i had it on my desk, a collega thought it was a new calculator ;)
The 35 is very usable but to say it has it all and th rest is window dressing ? I use the solve mode from my 15C and 35S very much. Things like last x too. Also the complex mode.
Just found out about the HP50G, looks like a more user friendly 48.
Nobody experience with the sharp pc1500 or 1211 ?

But as far as usability? I mean sure it's powerful, but do you think yo make any sacrifices using one of those?
Oh no, no sacrifices.. at all. It may have a steep learning curve, but its a "mini windows OS". Drop down menus.So C is cut, V is paste etc.. It got "My documents", it even boots the OS if it have been out of battery!
I have made a lot of ready "documents" that i need in my daily work. (I do electro acoustics's,lot of calculus, ordinary electronic work. Plus computer service and are part time studying for the moment quantum mechanics theory)
Its just going to the folder and get the ready formulas/projects up and key in the figures.
What is neat is that i can grab a line in a diagram/curve and drag it and it updates everything in the spreadsheet. Don't need to carry a laptop computer to do the calculations as before. (I`m in a wheelchair most of the day.)
But it may not be the "cup of whisky" for everyone, but for my needs its just a wet dream come true. ;)
But i also got a Casio fx5800P. A fx115MS and the bets of them the "Personal computer" CASIO FX720P that has served me for over 30 years now ..

I have a 42S app on my Nokia lumia and i had it on my desk, a collega thought it was a new calculator ;)
The 35 is very usable but to say it has it all and th rest is window dressing ? I use the solve mode from my 15C and 35S very much. Things like last x too. Also the complex mode.
Just found out about the HP50G, looks like a more user friendly 48.
Nobody experience with the sharp pc1500 or 1211 ?
The HP 45 introduces last x and feels more "modern" than the 35. But, only the 35 dedicates a key to pi. No shift! That's a real usability feature!
 Ken

I use a HP28S, which I got by trading a HP97 that I bought at a flea market for â‚¬3.50 8)

I have PA4TIM, through grad school. I use all the Sharp series, until the 1262. The 1211 I used the Radio Shack version.
(http://upload.wikimedia.org/wikipedia/commons/thumb/6/6f/SharpPC1211001.jpg/800pxSharpPC1211001.jpg)
(http://pocket.free.fr/images/sharp/pc1262.jpg)
Nobody experience with the sharp pc1500 or 1211 ?

I just saw this topic and like to add my experience.
When I was at university I started with HP28, than followed by HP28s, 48SX and finally the great 48GX. When my 48SX broke (this year) I looked for a replacement and thought about getting either HP50g or the TInspire and unfortunately bought the HP50g. Like robrenz said, after using HP48, the HP50g is a big disappointment. If I had to decide again I would get the TI.
Its a shame that my almost 20 year old HP48GX (which I still use every day in my office and emulated on all of my PCs) seems still to be the best (at least HP) calculator ever.

I have a 48GX app. It was a frightning complex thing at first, could not even found pi, but i found a HP tutorial manual and I begin to get it and like it more and more. Not so much for normal work, the 15C of 35/35S is more easy for this but the solve function is super because I can give the variables meaningfull names and see them in the screen, highlight the unknown one and press solve. Very handy.
I was in doubt about buying a 50G but it is rather expensive and I allready have a bunch of usefull calculators. But I really do need the solve function and on my other HPs it is not very userfriendly ( for me) I have to write down the program labels and variable names somewhere otherwise i never find them back.
So i probably should look for a 48GX.

So i probably should look for a 48GX.
IMO the best HP ever made and I owned every one since the 25C, they went downhill IMO after the 48GX. I have the app on my laptop and I use the real one in the shop every day.

Unfortunately the HP48GX is history! :'(

the solve function is super because I can give the variables meaningfull names and see them in the screen, highlight the unknown one and press solve. Very handy.
Download the manuals and check out the multiple equation solver it is even more awesome. It will link multiple equations with similar variables and solve using whatever equations it needs to get your answer.

just for comparison/fun, real and emulation is almost identical

Just saw it.
An amazing old calculator called ''Curta'' (http://www.youtube.com/watch?v=cndx5eKGjyU#ws)

(http://www.stevenjohnson.com/cardboard/images/lightningcalculator.jpg)
Even older (~19061910)

I searched the thread but it was only mentioned once:
EXCEL
Seriously you can just input the formula once and calculate it for multiple variables without reentering it into your calculator.
Else I use a TI84+.

EXCEL
Seriously you can just input the formula once and calculate it for multiple variables without reentering it into your calculator.
Unless you need complex numbers (possible to a limited degree, but painful with the IM* functions). Or correct statistics. Or an overview of all calculations in a worksheet. There are much better options available for mathematics if you have access to a fullblown PC. Even your average graphing calculator can handle more advanced math.

Excel is a pain to do simple calculator math since you have to wait for the program to launch and then set up your function, where a calculator is usually at hand. But I do agree that it is a powerful tool especially when working with large data sets. I also agree that there are more advanced math programs and those programs will take even longer to set up. So I think you should use the simplest tool possible for the given problem because it will be most efficient.

A beaten up HP12C from 1987. Still the King of the Financial Calculators
(http://upload.wikimedia.org/wikipedia/commons/9/94/Hp12c.jpg)

casio fx82tl, I bought it in 1998 for $20!

Just saw it.
An amazing old calculator called ''Curta'' (http://www.youtube.com/watch?v=cndx5eKGjyU#ws)
That is great, thanks a lot for showing. I almost forgot about this one. Many years ago I had a colleague who really did his university with this mechanical wonder (he earned his master degree as a "watch maker" at university Geneva). When I first had it in my own hands I was blown away and tried to buy it from him. But of course I had no chance to get it.
In my very early days I had to work with this

Excel is a pain to do simple calculator math since you have to wait for the program to launch and then set up your function, where a calculator is usually at hand. But I do agree that it is a powerful tool especially when working with large data sets. I also agree that there are more advanced math programs and those programs will take even longer to set up. So I think you should use the simplest tool possible for the given problem because it will be most efficient.
Excel coldboots under 2sec on my computer and a warmstart in under .5sec.
I can input much faster on my computer than on my TI84+.
And I wouldn't use excel for stuff like 1+2 more like actual formula's.
If I'm at a computer without excel then i just use Wolfram alpha.

Excel is a pain to do simple calculator math since you have to wait for the program to launch and then set up your function, where a calculator is usually at hand. But I do agree that it is a powerful tool especially when working with large data sets. I also agree that there are more advanced math programs and those programs will take even longer to set up. So I think you should use the simplest tool possible for the given problem because it will be most efficient.
Excel coldboots under 2sec on my computer and a warmstart in under .5sec.
I can input much faster on my computer than on my TI84+.
And I wouldn't use excel for stuff like 1+2 more like actual formula's.
If I'm at a computer without excel then i just use Wolfram alpha.
I did put all my formulas and calculations, and tables i need into my TInspire..
its a Ti84+ plus Excel and PC in one tool.. I do all the formulas finshed and load them from the PC into the TInspire and everything is a snap from there on to use. saves both time and the hazel of repeating the same keystrokes time after time.
(http://www.datamath.org/Graphing/Images/TINspireCX_CAS_P.jpg)

I use the spreadsheet openoffice. It is handy when having lots of data. But i use my calculators most often in my lab ( and most times I have no computer powered on there) or while designing and that I do while lying down without a computer, i draw schematics often on paper. ( i'm a bit disabled and can not sit very long) so a programmable calculator is more easy for me. Upto now the HP48GX app is becoming my favorite. I wanted to buy a HP50 but i read here that it is not as good as the 48 and they changed several things again , not handy because I'm just starting to know the 48.
I looked for used one, but they seem to cost even more as a new HP50, so it looks like the ipad app will stay my only HP48GX or maybe I better buy a HP50GX
Things I miss is the pi , lastx and x<>y button. I use those a lot. But i still have the 35's for the normal calculating jobs so not a real problem. What I like about the 50 is the size, huge screen and looks/layout. The 48 is ugly and so much knobs and text on it that I'm allways searching.
That is the thing I do not like from HP. On every calculator layout it complete different. Like pi is a yellow function on the 35s, a main buton on the 35, a blue function on the 15C and a softkey in a submenu on the 48, a yellow shift on the 42S ect. And brsides that every time above or under a different main key. ( like above Rdown on the 42S and above cos but under Rdown on the 35s)
Besides that, a spreadsheet does not have a solver. For instance my hp48GX app has one formula for the thompson resonance formula. And using the solver i can get frequency, L or C. In a spreadsheet I need 3 formulas for that.
That Ti enspire is a very nice looking calculator with nice options but I thing to complex for me. I never had TI and I like the way HP works. So I stick to HP

I can certainly agree to that, the calculator is like the IT infrastructure in a company, it got to mirror the true use and needs of the users. :)
TI nspire is not that difficult to learn, its mostly made as like as windows as possible. Its like a good book, you cant put it down when you got it i had it with me all the time the first month i had it, everywhere. So much to explore and the possibilities it has is so good. Cant live without it!
One things with it , on the CAS model is you have "what if" possibilities, gives a hole new dimension on problem solving in math, make a handle for a value and drag it with the mouse and everything in the calculation/tabels/curves/spreadsheets changes accordingly! Cant say how much that mean to me, but its so great!
So it cover my needs..
(http://www.eevblog.com/forum/generalchat/whatcalcultatordoyouuse/?action=dlattach;attach=33090;image)

Things I miss is the pi , lastx and x<>y button. I use those a lot.
The right cursor key under swap is x<>Y without needing the shift key. But last entry must be entered onto stack before using it because it acts as a cursor key while entering data. It works from the computer right cursor key also

I wanted to buy a HP50 but i read here that it is not as good as the 48 and they changed several things again , not handy because I'm just starting to know the 48.
If you are not yet "spoiled" by the real HP48, than the HP50g is probably acceptable for you. Functionwise and pricewise actually it is a lot better compared to the old 48
(If remember correctly I paid 500 DM for the 48GX, which would now be close to 250â‚¬ and for the 48SX I paid at least double of that price (with 128kB RAM card, HP solve equation Lib and serial interface kit)).
The main point I am disappointed with it, is the poor build quality compared to 48 Series, the look and feel and the many changes I struggle with. I just instead use my HP48GX, because I am faster. But if my 48GX brakes like my 48SX just did, I either have to get used to it or will go for the TInspire CX CAS.

(http://ecx.imagesamazon.com/images/I/51dqwm4QQhL._BO2,204,203,200_PIsitbstickerarrowclick,TopRight,35,76_AA300_SH20_OU01_.jpg)
http://www.amazon.com/TINspireForDummiesComputerTech/dp/1118004663/ref=pd_bxgy_e_img_y (http://www.amazon.com/TINspireForDummiesComputerTech/dp/1118004663/ref=pd_bxgy_e_img_y)
You can buy this book if go for the TInspire...
Gives you a speedy way into the best calculator there is .. :)
But the math with TInspire books by Brendan Keely is a joy to read and use.. highly recomended!!
The best there is..
(http://ecx.imagesamazon.com/images/I/51Nik89rRaL._SL500_AA300_.jpg)
http://www.amazon.com/Algebra2TInspireSemester1/dp/1895997402/ref=sr_1_5?s=books&ie=UTF8&qid=1352737322&sr=15&keywords=TINspire (http://www.amazon.com/Algebra2TInspireSemester1/dp/1895997402/ref=sr_1_5?s=books&ie=UTF8&qid=1352737322&sr=15&keywords=TINspire)

Besides that, a spreadsheet does not have a solver. For instance my hp48GX app has one formula for the thompson resonance formula. And using the solver i can get frequency, L or C. In a spreadsheet I need 3 formulas for that.
Toch wel hoor.
Excel has a solver although I have not used it myself.
https://www.google.be/search?q=excel+solver (https://www.google.be/search?q=excel+solver)

You can buy this book if go for the TInspire...
Gives you a speedy way into the best calculator there is .. :)
Have you used an HP calculator? The Nspire is a huge toy in comparison. The market reception is so poor that they are redesigning it http://tech.slashdot.org/story/12/11/11/1819236/colorscreenti84pluscalculatorleaked (http://tech.slashdot.org/story/12/11/11/1819236/colorscreenti84pluscalculatorleaked)
Sadly, they are redesigning it to look like the Casio FXCG20
For those more interested in proper tools rather than toys, you can now get ripoff sorry tribute emulations. Unusually, they are from Switzerland not China, and are credit card sized: http://www.rpncalc.ch/ (http://www.rpncalc.ch/)
production sample dm15cc (http://www.youtube.com/watch?v=b4QJAfETMSs#ws)
I wonder if Dave has seen these, they seem similar to his uCalc project.

That TI is very nice, can do a lot but as far as I can see it has no RPN. And I only use RPN. And not because I'm used to it for ages because 2 years ago I not even knew what it was, but since I have the 35S and tried RPN I'm hooked on it. It is so natural and the stack is also great.
A friend maybe has a HP48G for me ( according his dabase but that is not 100% up to date, he has several 1000 calculators) i hope he does because both my ipad 48 apps crash constantly and some functions do not work, or not allways. One is now so stuck I think have to reinstall it. In one the var function does not work, in the other the plot menu, and if It by accident does ok it won't leave the plot mode. Very frustating. Because I never know if I just do it wrong or it is a bug in the app

Yes, i have 4 HP calculators in my drawer.. (all of them more or less broken) and to what i need a TInspire for, no HP can do.. simple as that.. as i said earlier.. you got to have the right tool for the right job.. and for what i do, the TInspire is the best. Toy or not, its doing the job, like showing the graphs, and doing 3D graphics.. that is what i need and no HP can do it like the Tinspire can...
Besides my studies/ university materials i get are based on the TInspire. no options.
So get the picture; demand, use and what it deliver.. easy? ;)

I love my TI CX CAS's software.
But the hardware is the worst ever, to the point I would even prefer a chiclet keyboard!
There's still nothing like my old HP 48GX in that field :)

I love my TI CX CAS's software.
But the hardware is the worst ever, to the point I would even prefer a chiclet keyboard!
There's still nothing like my old HP 48GX in that field :)
Yeah, the keyboards is not great, but i have most of the things i do in it as finished formulas/dockuments, so its only data input i need to do.

I love my TI CX CAS's software.
But the hardware is the worst ever, to the point I would even prefer a chiclet keyboard!
There's still nothing like my old HP 48GX in that field :)
Yeah, the keyboards is not great, but i have most of the things i do in it as finished formulas/dockuments, so its only data input i need to do.
Define "not great"
Of all calculators i used in my life, it's the worst. I don't know what they were thinking... all other TI's were OK... extreme cost cutting...

I wonder for what range of values the solution "a pocket calculator" is optimal, when the question is "I need to draw colour 3D graphs and models".
What did you do to break so many calculators? I'm still using my HP28S from 1989, and my Casio fx2600P from 1983ish.

I wonder for what range of values the solution "a pocket calculator" is optimal, when the question is "I need to draw colour 3D graphs and models".
What did you do to break so many calculators? I'm still using my HP28S from 1989, and my Casio fx2600P from 1983ish.
I study at the moment Quantum Stochastic Calculus.. (Class is part of a "junior" study at CERN, same class is also found at MIT and Cornell in the US.) Quantum Algebra (math.QA) so the TI is perfect.. but for the heavier calculations we use wolfram for the more complex models. But for the understanding of covariant differential calculus, the Tinspire is at it best.
I have been using them "on site", ex the 4 years before the winter Olympics, i had one in my pocket all the time when we delivered all the sound reinforcement equipment. In all weather, on building sites, in rigs high over ground, in skislopes and in all temperatures. We had down to minus 32c in the nights when we had to reconfigure the speaker settings and directions in the slopes when they moved the track for the next day. The HPs did ok in about 510 minuts, they they gracefully dided, or the lcd froze, then it was to slip inside the jacket, pull out another one that was warm and start again. The warm cold change made humidety to build up, so they did not work well after that tretment. :D
Its not all of us that sit by a table all day, some has to work out on building sites, like the Gardemoen airport, did electroacoustics there.
But i have a calculator from 1976.. still up and running besides my casio FX720P like new.. two Tinspire models like brand new..
Today i my needs are coverd by the Ti, i dont have to move around with a laptop. So to my needs, its just perfect, size but keyboard is small , but i manage well. (I`m now in a weelchair and its difficult to move around with just that so evry ounce les to move around is great.).

+1 for the HP15C
Got mine back in the mid80s as part of doing my EE and it hasn't missed a beat since.
In addition, if noone else has mentioned it, there is a brilliant TCL/TK version of the 15C out there. It has become my goto desktop calculator
http://hp15c.homepage.tonline.de/content_web.htm (http://hp15c.homepage.tonline.de/content_web.htm)
.. mark.

I love this thread and I used many and love some of the devices presented here (more than I usually love anything that has buttons and eats electricity). And I am a "power user", I wrote programs for most of them (except for Sharp PC1xxx series which I never dug) and I had good experience with all clases of devices (notable exception for newer TIs maybe).
I troll ebay regularly for some Casio, Sharp, HP or TI that might catch my eye.
BUT I really can't use them anymore for anything more than simple calculations. I could get some HP48 in good conditions a while ago but really I couldn't do anything efficiently on it, except for making fun of friends who can't use it to do 3x2. I have a TI89 I actually used for a long while and boy it's frustrating to use. Yes, I know it's from before 2000 but even then I've been spoiled by Maple (even as far back as 1995 or so). Yes, it can do CAS but you can guess it doesn't mean much for a Maple user.
It's not a failure of one particular device, it's just the limitations of the number of keys, screen size/resolution and processing power. If you have a big screen and a full keyboard of course you can just have some nice worksheet and source code and everything layed out in front of you. But if you are limited you need to assign multiple tasks to the same button, have shortcuts you need to keep in your head, etc.

Casio calculator is the best for the math and all other works like small working..but in my point of view calculator is not used in small question like 45*2 these type of question is not for the calculator that it give the answer...

Just put new batteries in my HP11c, it must be 10 years since I have done that.
Please HP revive it! there is a whole generation missing the joy of RPN  you still have the 12c for the bean counters after all !

I have a Casio CFX9850GC Plus which I hate  happy to sell it ;)
My Sharp EL506W is not for sale! I find this calculator a pleasure to use  Hex/Bin/Oct and logic operations do not need any fancy menu stuff, and all the standard maths functions are available.
http://sharpworld.com/products/calculators/sc_calculator/el506w/index.html (http://sharpworld.com/products/calculators/sc_calculator/el506w/index.html)
I also have a Casio FX6300G which is a great old calculator, but not available now. I REALLY dont like the recent Casios.

I get by just fine with a TI30XA. Thin, inexpensive, and fairly capable.

Please HP revive it! there is a whole generation missing the joy of RPN  you still have the 12c for the bean counters after all !
Look at the type of people who now run HP :( and you know why.

Alas, agree fully with B@W. The HP you know that built those calculators is mostly Agilent today.
Please HP revive it! there is a whole generation missing the joy of RPN  you still have the 12c for the bean counters after all !
Look at the type of people who now run HP :( and you know why.

I'd always loved my Sharp calc but it's been showing it's age recently; so when I saw this almost identical elcrapo for Â£5 in Tesco the other week, I just had to get it!! you can just smell the cheap plastic!! I love it!!
(http://tinypixels.co.uk/test_equip/calc/tesco_calc.jpg)

I'd always loved my Sharp calc but it's been showing it's age recently; so when I saw this almost identical elcrapo for Â£5 in Tesco the other week, I just had to get it!! you can just smell the cheap plastic!! I love it!!
That looks so similar it's like it has to be using the same chip. Does it give the same numerical results?

I'd always loved my Sharp calc but it's been showing it's age recently; so when I saw this almost identical elcrapo for Â£5 in Tesco the other week, I just had to get it!! you can just smell the cheap plastic!! I love it!!
That looks so similar it's like it has to be using the same chip. Does it give the same numerical results?
Hi yes I believe the numerical results are the same; so like you say it's more than likely the same chipset.

HP48 emulator on HTC android phone. The original is too heavy/precious to take with me :)
Sent from my HTC One S using Tapatalk 2

I'd always loved my Sharp calc but it's been showing it's age recently; so when I saw this almost identical elcrapo for Â£5 in Tesco the other week, I just had to get it!! you can just smell the cheap plastic!! I love it!!
I have been using almost the same Sharp since 1987! It is an EL512 with 4 extra programmable functions. It's beautiful with very very soft keys, something I did not have with my previous Texas Instruments brand calculators, they were horrible in this respect. I lost the 1st Sharp EL512 in 1987 a few months after I bought it, then I bought a new identical one, a heavy burden on my student's budget then. Yesterday I have opened and cleaned the contacts under the keys, it is now as good as before.

Being a student you will inevitably lose your calculator every now and then and run into shitty calculators because your budget is not that much ._.
I just use a Sharp EL509WS (Worst contrast ever) that goes for roughly about 10$ ? For my exams, other times i use a plethora of calculator emulators on my phone
Mainly the Andie Graph with the TI86 ROM inside as well as the Graph 89 Free with the 89 Ti ROM inside, oddly i never use the Droid48 because i do not know how to make use of RPN mainly but my favourite calculator is the TI86!

I'd always loved my Sharp calc but it's been showing it's age recently; so when I saw this almost identical elcrapo for Â£5 in Tesco the other week, I just had to get it!! you can just smell the cheap plastic!! I love it!!
That looks so similar it's like it has to be using the same chip. Does it give the same numerical results?
Hi yes I believe the numerical results are the same; so like you say it's more than likely the same chipset.
Did you test it with this?
http://www.rskey.org/~mwsebastian/miscprj/forensics.htm#algorithm (http://www.rskey.org/~mwsebastian/miscprj/forensics.htm#algorithm)
According to the result table:
http://www.rskey.org/~mwsebastian/miscprj/models.htm (http://www.rskey.org/~mwsebastian/miscprj/models.htm)
The EL506P used two different chipsets depending on the year.

I'd always loved my Sharp calc but it's been showing it's age recently; so when I saw this almost identical elcrapo for Â£5 in Tesco the other week, I just had to get it!! you can just smell the cheap plastic!! I love it!!
That looks so similar it's like it has to be using the same chip. Does it give the same numerical results?
Hi yes I believe the numerical results are the same; so like you say it's more than likely the same chipset.
Did you test it with this?
http://www.rskey.org/~mwsebastian/miscprj/forensics.htm#algorithm (http://www.rskey.org/~mwsebastian/miscprj/forensics.htm#algorithm)
According to the result table:
http://www.rskey.org/~mwsebastian/miscprj/models.htm (http://www.rskey.org/~mwsebastian/miscprj/models.htm)
The EL506P used two different chipsets depending on the year.
great site! both calcs came out as 8.99999863704 so according the lookup "Sharp EL506P (mid80s, earlier version)" and the "Sharp SC6992" chip. So I cracked them open and took a pic. (left elcrapo, right is the sharp el506p)
(http://tinypixels.co.uk/test_equip/calc/calc_chip_s.png)

That's interesting. Because I just worked with Excel2010 before I saw this. I tried it and was very surprised when
ARCSIN(ARCCOS(ARCTAN(TAN(COS(SIN(9))))))=0,42477796076938 showed up.
This seems to be the result with radians instead of degree angle. Does anyone know how to change this in excel.
Then I did the same test: arcsin (arccos (arctan (tan (cos (sin (9) ) ) ) ) )
with my HP48GX, HP50g, HP48GX emulator on Android and Windows 7 64bit
result always was 8.99999864267 (as stated in the article).
greetings from Germany

TI nspire CX CAS  lost my ti89 so this replaced it
ti84 for easy arithmetic
matlab & Excel for numerical analysis

I tried my 35, 35s, 15C, 15C app they all agreed with the table
Tried my 45 ipad app and 42S windowsPhone app and they do not agree.
The 45 gives 9.000000000
The 42S gives 9.0000000004

Evidently computers may have an advantage over calculators. This is what my calculator program produces:
> 180/pi * asin acos atan tan cos sin (9/180*pi)
9
> ans  9
1.06581410364e014
>
Perhaps calculators these days should simply be based on an ordinary micro and do IEEE double precision arithmetic in binary?

Evidently computers may have an advantage over calculators. This is what my calculator program produces:
> 180/pi * asin acos atan tan cos sin (9/180*pi)
9
> ans  9
1.06581410364e014
>
Perhaps calculators these days should simply be based on an ordinary micro and do IEEE double precision arithmetic in binary?
OK, not quite the right test. My program doesn't have a degrees mode. Here is keeping everything in degrees:
> d=180/pi
57.2957795131
> r=pi/180
0.0174532925199
> d*asin(d*acos(d*atan(tan(r*cos(r*sin(r*9))))))
8.99999999983
>
Now the result is not quite so close. Maybe I need quadruple precision...

The Windows 7 Calculator:
asind(acosd(atand(tand(cosd(sind(9))))))  9
3.3055861301806391104645128745734e32
Close enough 8)

Evidently computers may have an advantage over calculators. This is what my calculator program produces:
> 180/pi * asin acos atan tan cos sin (9/180*pi)
9
> ans  9
1.06581410364e014
>
141620 digits (or even much more) precision is nothing, even 64kB RAM devices should to that easily.
This is what computers do:
> 180*arcsin(arccos(arctan(tan(cos(sin(9*Pi*(1/180)))))))/Pi;
9
> arccos(arctan(tan(cos(sin(9*Pi*(1/180))))));
Pi
sin()
20
That's a 9 of course.
With a (newish) Maple but I'm convinced even the V5 from 1997 would do the same.

In fact I was too quick with the example above, this is the one that does something closer to the "fingerprinting" test (before I put only the first and last conversion):
> 180/Pi*arcsin(180/Pi*arccos(180/Pi*arctan(tan(Pi/180*(cos(Pi/180*(sin(9*Pi/180))))))));
9
> %9;
0
Of course the functions can be redefined to work in degrees directly but it's not worth it. Also some intermediary result (as in didn't type all conversions) from Maple:
> 180/Pi*arcsin(arccos(180/Pi*arctan(tan(Pi/180*(cos(Pi/180*(sin(9*Pi/180))))))));
Pi
180 arcsin(1/180 Pi sin())
20

Pi

That's interesting. Because I just worked with Excel2010 before I saw this. I tried it and was very surprised when
ARCSIN(ARCCOS(ARCTAN(TAN(COS(SIN(9))))))=0,42477796076938 showed up.
This seems to be the result with radians instead of degree angle. Does anyone know how to change this in excel.
I use EXCEL 2003, and for what I understand it works in radians, not in degrees.
There is a function that converts radians in degrees (GRADI in my Italian Excel) and another one to convert degrees in radians (RADIANTI).
I get lost with long formulas in Excel, so I prefer to put every single part of the formula in a separate cell.
The following image is a screeenshot of the formula, showing the great accuracy of the result.
Best regards

Technically to do the same as the pocket calculators you'll need to convert each function in between to radian operation, not only first and last one (easy trap, I went for it as well, see above).
Also it would be interesting to see what is I19 or even better (I19)*100000000 for example to see if anything hides behind 9.0000...
Open question: anyone knows some "pocket calculator" where you can set higher precision for this kind of operations? And I mean larger than the usual 820 digits, maybe 50100, or even much more. This isn't a really challenging task in itself assuming you have reasonable RAM (and by that I mean even 12MB would be plenty), probably the hard part is the user interface itself.
And this can have (somehow) practical applications... for example: http://whatif.xkcd.com/20/ (http://whatif.xkcd.com/20/)
At some point the damn cat steps on the keyboard ... and we start with a speed of 0.9999999999999999999999951c (that is almost c, speed of light, max speed permitted in this universe). You just can't do 10.9999999999999999999999951^2 (for example) on any calculator I know of (or I don't know how). And you might need precisely this speed squared, it is something that comes up immediately in this context.
Of course you can do it on paper "old style" like you transform your number in something like (149/10^25) and then you do by hand (149/10^25)^2. But sometimes you have stuff that doesn't play that nice or you just want to do the calculation and get the result without any tricks.
So, is there any pocket calculator that can do 10.9999999999999999999999951^2 with some reasonable precision ?

So, is there any pocket calculator that can do 10.9999999999999999999999951^2 with some reasonable precision?
Fortunately you don't need a calculator for this. You can do this one in your head (well OK, you might need a pencil and the back of an envelope).
First of all we need 0.9999999999999999999999951^2. A quick application of the binomial theorem tells us that the answer is 0.9999999999999999999999902 (we subtract 51 from 100 to give 49, double it to give 98, subtract that from 100 to give 02, and replace 51 with 02).
Next we need to know 1  0.9999999999999999999999902. This is easily seen to be 0.0000000000000000000000098, or 9.8 x 10^{24}.
And there's our answer.

As I mentioned above the question isn't how to do (149/10^25)^2 by hand, that is clear. By the way from
(ab)=a^22ab+b^2
you ignored b^2 because b is very small (49/10^25 in our case) and b^2 is even smaller; this is fine (in fact this is THE way you do it on paper usually). However sometimes you just don't want to think how to expand a given expression, sometimes it isn't possible, etc.
I don't want arbitrary/infinite precision, I don't want clever optimizations or a symbolical calculation engine that knows more tricks than most math students, I just want some calculator that uses more than the usual 8121620 digits for the "significant digits" in the float/scientific numbers. It's not that much a question of resources, the "standard" quad precision will give you roughly 34 digits while using 16 bytes (including for sign and signed exponent). It isn't that much and it wouldn't be even if have it 10x or 20x times larger. But problem is everything (I mean scientific calculators, including TI89) don't do even half of that.

There are programs and languages that can handle as many digits as you like, just limited by the amount of memory there is.

I just want some calculator that uses more than the usual 8121620 digits for the "significant digits" in the float/scientific numbers. It's not that much a question of resources, the "standard" quad precision will give you roughly 34 digits while using 16 bytes (including for sign and signed exponent). It isn't that much and it wouldn't be even if have it 10x or 20x times larger. But problem is everything (I mean scientific calculators, including TI89) don't do even half of that.
The good thing about programmable calculators is that you can program most of them to do arbitraryprecision calculations. As for why the stock firmware doesn't: most likely not many people have a use for that, even for scientific calculators. In practice, ~10 significant digits are plenty; even the fundamental constants of the universe are rarely more accurate than that.

Calculator with Ubuntu:
(180)Ã—asin(acos(atan(tan(cos(sin(9/180))))))?9
= 9
It uses bignum, so can be very precise. I think Windows Calculator uses a bignum calculation too.

I know about computer programs, for kicks I just recovered from the very first CD I ever burned Maple V Rel 3 (1994!). It would run in 2MB of RAM (possibly 1) and do miracles. "bc" is the GPL tool of choice for this kind of things, comes with most linuxes by default; this is before we go full blown Sage or something similar.
And yes, I did find something for the programmable calculators: http://www.hpcalc.org/details.php?id=1320 (http://www.hpcalc.org/details.php?id=1320)
You can look in the PDFs from the archive, LONG.PDF for example, just what the doctor ordered. As opposed to what I've found for TI this one would also do much more than 4 operations, it would do all the usual transcendent ones you need (sin, cos, whatever).
As for practical use I mentioned in the previous example, sometimes you just need to add/substract (or do similar but more complicated stuff, like sin(a)sin(b)) things of wildly different orders of magnitude. Any scientific calculator knows what 1 is and what 1/10^25 (or even much smaller numbers) is. But if you add them together the result will be on most calculators ... 1. That is fine in itself ... unless you need to substract this "1", in which case you'll get 0 instead of whatever number you're really interested in.

And here's another funny one; I mentioned GNU bc above which is coming with basically any linux for quite a while. Guess what, I can't find the Android port/version!!!
BUT I could find Windows, Windows CE and iPhone versions!!!! WTF?
http://www.appover.com/search/bcmobile/349255871/ (http://www.appover.com/search/bcmobile/349255871/)
http://gnuwin32.sourceforge.net/packages/bc.htm (http://gnuwin32.sourceforge.net/packages/bc.htm)
http://www.findbestopensource.com/product/yabcalc (http://www.findbestopensource.com/product/yabcalc)

I mentioned GNU bc above which is coming with basically any linux for quite a while.
Or why not use the dc command instead and get the good stuff (RPN) ;)

My new calculator. A HP48G. The PC1500 and plotter did not work. looked great but nicads and batterys had leaked and did severe damage. The 1500 gives some image but the 3,7Vdisp. is not more as 1.5V and it draws 25mA even when powered off so something is wrong. If it was not all the battery damage I would give repairing a try.
And just finnished repair, a HP9100A, I have also a 9100B here but that is in very bad shape, faulty HV (Q1 dead), fautlty PSU, missing CRT, non functioning processor, lots of damage by salt water. Probably not fixable. Both are not mine but from a museum.
(http://www.pa4tim.nl/wpcontent/uploads/2012/11/9100Aklaar.jpg)

Been fighting with Korad power supply, no matter, long story short  I need to increment 0.009A with 0.001. Well....... guess what (this is python):
>>> a=0.001+0.009
>>> print(a)
0.01
>>> b=1000*a
>>> print(b)
10.0
>>> print(int(b))
9
(I know WHY this is but really, pretty shocking).

I started with some really old HP/TI calculators  brown plastic with yellow gold lines, led disiplay.
Then some Casio VFD calculators. Then FX80/82, Sharp EL502, some Casio programmable, ...
Now, I am on 12C  love it.

The calculators I use most often are:
1. HP 32S II (RPN)
2. HP 15C (RPN)
3. Sharp PC1350 for fast programming with good size display
4. Sharp PC1600 for more advanced programming and 4 color plotter.
The Sharp PC's are connected to the laptop via RS232 and all programs are stored.
Anything more complex is done on the PC

Or why not use the dc command instead and get the good stuff (RPN) ;)
That is precisely what I use.
Interesting that the above comment was posted exactly two years ago today. (Or should I say "2 365 * p" days ago.)
I just did a currency conversion on the command line before reloading the forum too.

Answer to question: Ti 89 Platinum.

If you don't have to contend with exam rules, just get the best one available for less than 150us if you shop around:
 TI cx cas (think of it as a modern TI 89).
 HP prime or 50 (question of taste).
 Casio 991 as a pocket rocket.
On a side note, I just scored a new TI Nspire Touchpad for 1â‚¬ and I'm happy as a geek with a calculator.

I had a TI83 attending ITT Technical Institute in the late 90's. Lent it to my stepdaughter when she was in high school and it was promptly stolen. Just grabbed a TI82 at a hamfest for $2 with minor screen issue and I have realCalc on my Nook HD+

I used to have a Sharp EL 506P, not sure what happened to it. Did replace it with an EL 506L because my main use for them was/is base conversion.
Now I just use the Windows calculator, although I don't like the change they made in Windows 7 that separates the programmer mode from the scientific mode.
The EL 506L is still around in my desk but I rarely power it up.
Edit: added image since there is a newer 506L model it seems.
(http://www.eevblog.com/forum/chat/whatcalcultatordoyouuse/?action=dlattach;attach=120263;image)

Casio fx570ES

I still find using hardware calculators for brainstorming, field calculations and cross checking my software faster than using RealCalc on my phone or software calculators on the PC, except when I have to transfer numbers often to another app for further evaluation.
When US schools went on summer break, Walmart and Amazon dumped inventory on the Casio FX260 for $6, FS115ES [ called FS991ES elsewhere] For $11 and the TI36XPro for $18. I picked up a few Casios and a TI.
The last two are staples in US colleges for math and engineering courses. They can do definite integrals, polynomials, expression evaluation and much more, have been around for nearly 15 years [ as prior model, without 'ES' for Casio or Pro for TI] and have been reviewed extensively by many for strenghts and weaknesses.
I've never liked the first version of VPAM and wrote such calculators off for many years. But the updated 'VPAM' or textbook displays look very much like you'd write on paper and make entering fairly complex equations into these calculators easier.
Graduates of colleges >=15 years are likely seasoned veterans of these calculators but those of us who were in school before that will find these capabilities another timesaver worth a look, given the cost of these calculators.
There are also 2 other competing units with a similar breath of functions from Sharp and Canon, but they cost more and can be hard to find. Casio and TI are the leaders in the education fields worldwide and one reason [ if not the only reason] these calculators are still made or so cheap.

A 25 year old very battered HP 15C. This thread has just made me realise how long it's stayed with me through good and bad, one of the few things that's stayed on my desk for more than a few weeks ;)
Can't see me ever using anything else now, so much so that I've just been trawling eBay looking for a backup one, bloody hell they are more expensive now than when I bought it 25 years ago!!
Some years ago I sold the almost unused HP 16C I had, that fetched an astonishing amount on eBay.
Gasp... just found out they did a limited edition reissue of it in 2012  $180 list price and they're now selling for $600+ !! Reviews of it aren't very good either, the quality just isn't there.
ahhh and look at these...
http://www.swissmicros.com/ (http://www.swissmicros.com/)

A 25 year old very battered HP 15C. This thread has just made me realise how long it's stayed with me through good and bad, one of the few things that's stayed on my desk for more than a few weeks ;)
Can't see me ever using anything else now, so much so that I've just been trawling eBay looking for a backup one, bloody hell they are more expensive now than when I bought it 25 years ago!!
Some years ago I sold the almost unused HP 16C I had, that fetched an astonishing amount on eBay.
Gasp... just found out they did a limited edition reissue of it in 2012  $180 list price and they're now selling for $600+ !! Reviews of it aren't very good either, the quality just isn't there.
ahhh and look at these...
http://www.swissmicros.com/ (http://www.swissmicros.com/)
I did buy 4 pieces of the limited version of the 15C in 2012. The price I paid was just $ 125 and I thought it was a lot.
One for me a three for my friends. I should have bought 10 or more of them, knowing now that they go for so much.
The Swiss Micros clone is good as well, I have that one in my pocket all the time.
Also, there is a really good 15C APP for the iPhone and it works really well too.
The 15C is probably the best calculator ever made.

I finally replaced my HP48 with an HP50g. My only complaint about the HP50g is that it is slower latency wise than the HP48. I would like to know how they managed that with orders of magnitude higher processor performance.
If I could find a solar powered RPN calculator, I would consider it for when I do not want to carry the HP50g.

HP41C.
And the thing to its right is a Ti58 undergoing heavy surgery. It suffered a nearly fatal electrolyte leakage from the battery pack. After some cleaning and resoldering of several component, the calculator restarted, but the keypad is dead...

HP 67 & HP 25, still the best in the business. eh, for the old school guys!
Sometimes if I can stand to wait, I might use the Computer but the 67 boots much faster.

, non functioning processor, lots of damage by salt water. Probably not fixable. Both are not mine but from a museum.
Sea water? :P

I think I have a new favorite for 2015: Sage.
I am a longtime (~20 years!) Maple user (and that was my goto program for anything more than what you can put (now) in Google Calculator). However using software that starts from triple digits for students and goes (easily) into thousands for anything commercial at all is totally a show stopper in most cases I deal with. I have nothing at all against commercial and even expensive commercial turnkey solutions but they aren't for what I deal with. Plus I didn't like the programming part at all in Maple.
Using something GPLed or similar to do math just feels better. I was actually surprised to recently find a somewhat old document: http://wstein.org/mathsoftbio/history.pdf (http://wstein.org/mathsoftbio/history.pdf) where William Stein (Sage's Linus so to speak) basically expresses the same feeling (plus he does something about it instead of wasting time for 20 years like me).
Of course over the years I tried (as well) SAGE but it was breaking too easily, it would not install without extra steps, etc. However now it just works. It installs on ubuntu (and most likely on many other distributions) with one command.
And programming is pythonbased (the modern language I am most productive in, not that it means much). And there is a public server anybody can use if you don't have linux and you don't want to bother with a virtual machine: cloud.sagemath.com
What more can you ask for?

HP 32S II RPG is my goto calculator. Over the years I was frequently amused when someone would ask to borrow/use my calculator for a quick results only to see them stare for way too long looking for the equals button. :DD

I use a Casio fx991MS, excellent calculator, has engineering notation input and outputs too!

HP 32S II RPG is my goto calculator. Over the years I was frequently amused when someone would ask to borrow/use my calculator for a quick results only to see them stare for way too long looking for the equals button. :DD
+1
Happens again and again and is always funny to watch

Even funnier is replacing the built in calculator on a PC with a RPN version. Or set it to octal mode. That one can be really confusing as it seems to work...........

Speaking of that  try either in normal windows cmd or linux:
ping 192.168.0.01
(doesn't matter your network, should be working as expected, either timeout or answer, whatever  and do not forget the extra 0)
you can continue with any or all below:
ping 192.168.0.02
ping 192.168.0.03
ping 192.168.0.04
ping 192.168.0.05
ping 192.168.0.06
ping 192.168.0.07
Still nothing special, works as expected.
and then the surprise comes:
ping 192.168.0.08
WTF IS GOING ON!
(and the same with 192.168.0.09 for that matter)!

Obviously the leading zero indicates that the number is octal. Since 8 is not a valid octal digit, the command fails.
This is a pretty common trap for young players using the C standard library. Functions like atoi() treat numbers with leading zeros as octal.
Hmm not quite... ANSI Standard C atoi() only supports base 10 ASCII values, strtol() and other some functions support alternate bases such as hexadecimal and octal.

I use a Casio CD300es plus

I use a Casio fx991MS, excellent calculator, has engineering notation input and outputs too!
Yes, my favourite too. I always use engineering mode and the keys are very handy.

+1 for FX991 (ES model here)

Here's mine, i score it for 1 dollar ! ( the seller thought it was a phone ! *hahaha* )
(http://i1313.photobucket.com/albums/t545/VERYlowbudgetRC/Mobile%20Uploads/6cf6f886d8f6477ab2caeb179ee4603f_zpsdaeaa3a3.jpg) (http://s1313.photobucket.com/user/VERYlowbudgetRC/media/Mobile%20Uploads/6cf6f886d8f6477ab2caeb179ee4603f_zpsdaeaa3a3.jpg.html)
He doesn't look too amused. ;D ( the stick man that is )
Ps: i've had it for more than two years already and it only started to get a little dicky now, i guess the memory backup battery is dying ( the battery cost me twice as much as the calculator ! )

Other than a couple of mentions in previous posts, no one claims the HP 41C as a daily driver?
:+ OK, I will. Actually, one is a 41CV, with a second soon to be a 41CL.

Other than a couple of mentions in previous posts, no one claims the HP 41C as a daily driver?
:+ OK, I will. Actually, one is a 41CV, with a second soon to be a 41CL.
This must have been in the early 80's when I had a HP 41C, and it was awesome.
In those days I also had a TI 58C (that one kept the programming when turned off)
And later the TI 59 with magnetic stripes for programming
At one time I sold them all and got a Sharp PC1600
... the good old days

Other than a couple of mentions in previous posts, no one claims the HP 41C as a daily driver?
:+ OK, I will. Actually, one is a 41CV, with a second soon to be a 41CL.
I have used every hp since the 25 except the 35C. I think the 41C was the first to have the backspace key :+.
But IMO it was the worst/cheapest construction of any HP calculator ever made. The one that I never let go and still use daily today is the 48GX.

Anyone else tried the WP34S?
It's an HP 30b (or 20b) business calculator that is programmed with a new communitywritten scientific RPN calculator firmware.
I recently bought the 30b, reprogrammed it, and printed an extremely ugly and confusing key overlay for it ( you can get better proper sticker overlays online, I should probably get one.. ). I've had it at work on my desk for a while now, but I haven't really had a lot of time to play with it.
From what I've tried it seems to work pretty well, but I think I still prefer the HP 32SII that I have home.

I have one of the groups WP 34S, the stickers tend to make it lose that HP feel and look, but is does work well.
In my office I use a 32sII , in the 'shack' a 35S.

In the office, an HP 32Sii  the last of the great HP's, off an eBay seller in Belgium
At home desk is an HP48GX 'the mother of all calculators' bought new around 1992
At home lab bench is an HP11C, still my favourite, bought new around 1984, and now on its second set of batteries
I also have a 15C LE, one of the last of the batch 'just because'; an HP45 (works, but dodgy switch contacts somewhere) which was rescued from the skip when a former employer closed down; A TI59 with PC100 print cradle (awaiting restoration) from the same source; another TI59 bought new around 1979 and also in need of renovation; an HP20 which was a free gift from a supplier; and a 1970's fourfunction desktop with VF display and 'computer' style keys

I've been looking to buy an HP Prime (http://www8.hp.com/us/en/products/calculators/productdetail.html?oid=5367463) for a while. Only partial RPN support, I think, but a capable fast calc nonetheless.

I've got an HP11/48G/48GX and a TI83
The 48's see the most use
RPN FTW 8)

I have a TI30X Pro.
I like the UI because you input everything the way you would write it, with fractions, roots and so on, not like some other ones where you have to put in the value first and then press root.
The other thing I find very useful is that you can calculate with complex numbers.

I've been looking to buy an HP Prime (http://www8.hp.com/us/en/products/calculators/productdetail.html?oid=5367463) for a while. Only partial RPN support, I think, but a capable fast calc nonetheless.
I'm getting one as soon as I can.
The CAS side is being improved continuously. The only big problems remain the mass storage that does not work and you can't do a series that starts with 0.
http://tiplanet.org/forum/viewtopic.php?p=174931&lang=en (http://tiplanet.org/forum/viewtopic.php?p=174931&lang=en)
The person that posts under "Parisse" is actually the creator of the CAS software of the HP Prime.
(It's in French  use Google Translate :) )

I'm pretty much using a whole bunch of calculators.
My most precious ones are the HP 32S II and my Philips SBC 1745.
I got the Philips one from my brother after he finished school, and it took me through school as well.
I rescued the HP from the office dumpster. My colleague got it because he requested a new calculator. The department assistant ordered it, not knowing anything about calculators. I assume she just picked the most expensive one at the time. The guy threw it out because he couldn't deal with the RPN.
But those two are mostly for memories.
For actual work I use my TI92 II at home, and my TI89 Platinum in the office.
The 92 helped me a lot while studying, and a while ago I bought the 89 because of its portability (and because it doesn't scare my colleagues as much >:D)
I really like the graphing abilities and the representation of formulae on the rather big display.
Also being able to program and use apps like TISpice is a nice treat.
If I'd be set to zero and had to chose, I would buy the TI89 again.
For me, it's the most versatile of all calculators I have tried.
btw: To give it a try, I picked up the HP SmartCalc 300s a while ago. (yes the blue plasticky one)
While it's a decent and cheap (10 EUR) everyday office calculator, its build quality certainly does not deserve the HP logo.
It's a bid sad, that HP missed the opportunity to produce something great again.

I have a TI83:
(http://upload.wikimedia.org/wikipedia/commons/thumb/4/4d/TI83.png/266pxTI83.png)
But I don't use something like that often. In highschool we need mostly mathematical proof, as is on our university. I even remember one exam in wich we had to do an iterative calculation without advanced calculator!
In my university, an advanced calculator (by which I mean programmable and with graphic display) is allowed, but usually it don't is beneficial since you have to provide mathematical proof.Or we use excel.
So most of the time I use this for a calcuator:
(http://mulderthuis.nl/calculators/pictures/casiofx82tl.jpg)
It has full functionallity and keys which don't get stuck. Since I use it the most, I can work the fastest with this one; which is essential for my exams. What I don't like is that you cannot turn of the thousands separator  this was possible with the previous edition which I killed or lost. You can choose between a dot and a comma, I hate this, it is easy to read it wrong or confuse those; I would have preferred a space or no separator at all.

I use a TI84. Z80 inside :D
(http://i58.tinypic.com/wtae08.jpg)

HP15C, plus I have a few HP12C floating around here somewhere.

I use a TI84. Z80 inside :D
(http://i58.tinypic.com/wtae08.jpg)
There's a new model, with an eZ80 inside.
The one made for the French market is very interesting due to it's exact maths engine (but no CAS  for now).
It now has no more disadvantages to the CASIO equivalents.

So most of the time I use this for a calcuator:
I have a fx82 from early 1980s and it still works.
They are not super accurate, however.

In the office, an HP 32Sii  the last of the great HP's, off an eBay seller in Belgium
At home desk is an HP48GX 'the mother of all calculators' bought new around 1992
At home lab bench is an HP11C, still my favourite, bought new around 1984, and now on its second set of batteries
I also have a 15C LE, one of the last of the batch 'just because'; an HP45 (works, but dodgy switch contacts somewhere) which was rescued from the skip when a former employer closed down; A TI59 with PC100 print cradle (awaiting restoration) from the same source; another TI59 bought new around 1979 and also in need of renovation; an HP20 which was a free gift from a supplier; and a 1970's fourfunction desktop with VF display and 'computer' style keys
Update: I've started work on my original TI59 and it will now do sums for me when running off a bench supply (3.75V @ 110mA). I have disassembled the battery pack using brute force & ignorance and removed the decomposing NiCd cells. The pack was removed from the calculator long ago, but not before corrosion caused the +ve contact spring to break off the calculator main PCB. So the next steps are to disassemble the calculator and remove the main PCB; make & solder in a new contact spring; rebuild the battery pack using NiMH cells; and last but not least, overhaul the magnetic card reader. We'll see how that goes...
In other news, I've been repairing my father's HP33E (1979) which had a broken case due to being used with Alkaline primary cells, that are rather longer than the original NiCd's. I've glued the bits back together with epoxy & sourced some 'flat top' NiMH cells. Final assembly tonight! This calculator is otherwise functional.
And I scored a 'cheap' HP42S from a local seller off eBay (well, cheap for an HP42S anyway)
Happy days!

Anyone else tried the WP34S?
It's an HP 30b (or 20b) business calculator that is programmed with a new communitywritten scientific RPN calculator firmware.
I recently bought the 30b, reprogrammed it, and printed an extremely ugly and confusing key overlay for it ( you can get better proper sticker overlays online, I should probably get one.. ). I've had it at work on my desk for a while now, but I haven't really had a lot of time to play with it.
From what I've tried it seems to work pretty well, but I think I still prefer the HP 32SII that I have home.
like this one?
(https://farm4.staticflickr.com/3731/13318823614_7596ca233c_b.jpg)
(https://farm4.staticflickr.com/3831/13318615463_0a35ecf2c0_b.jpg)

That looks awesome. There is NO CHANCE IN HELL that I would be able to get those stickers on that well, though. I'd wind up throwing the whole thing out a window after a few minutes, so kudos to you and your dexterity.

you'd be surprised! I don't have a super steady hand anymore (coffee, age, etc) and my eyesight is even worse ;) the technique was just to peel the sticker off with the edge of a mostly dull xacto knife and use that to support the sticker while you center it on the key. there's a little wiggle room for adjustment since its not a very strong adhesive.
the printing was not perfect, though; some white dots in the corners can be seen on some keys. maybe it was the cutting process that caused it, but you can see them if you look closely enough.
but all that as it is, its still a 'more than good enough' effect and I would not have believed that stickon keys would come out this good.
the SOB part was flashing the calc. if you do this, buy pogopins (spring things) and build a jig. I had to give up and tack solder kynar 30ga wire to the contacts to get a successful firmware flash. pressing on the contacts by hand never worked and I tried many many times. I think I used a regular ftdi (probably even fake, lol) dongle to convert usb into serial/ttl which is what that thing needed (either 5 or 3v levels, but my dongle had a selectable switch for output level).

WP34S ! I want one.

WP34S ! I want one.
Me too. Seems it's also a free App!
(http://a1.mzstatic.com/us/r30/Purple1/v4/5e/6c/79/5e6c79fe25855a83333753f965198983/screen568x568.jpeg)

WP34S ! I want one.
Here you go: http://downloads.sourceforge.net/project/wp34s/wp34s_V3.zip (http://downloads.sourceforge.net/project/wp34s/wp34s_V3.zip)

I wish HP would retool the old HP29C or 41CX.

I wish HP would retool the old HP29C or 41CX.
HP retooled the 15C and then only as a limited edition
Most likely they will not do it for other models, because there is not much money to be made with calculators anymore.

I was using the EC130, but she is getting a bit cranky nowadays,
so my Sharp EL506P has proven slightly more sophisticated for the more complex stuff and oddly it still has the same battery as when I purchased it in 1984.....
(http://EC130 smaller.jpg)

I wish HP would retool the old HP29C or 41CX.
HP retooled the 15C and then only as a limited edition
Most likely they will not do it for other models, because there is not much money to be made with calculators anymore.
So true. I never loved the LCD display on the 15C. I do love the alpha display on the 41CX or any old LED 7 segment display.
Of course I now use my iPad as a big calculator, I've got an old TI59, HP29C and 41CX and I love the keyboards but don't use them much.

I use HP41CX both physically and emulated on the Smart phone. Also use HP12C again the real thing and emulated. The emulations are great in that I can have my fav calculators with me no matter what the circumstances.

I use HP41CX both physically and emulated on the Smart phone. Also use HP12C again the real thing and emulated. The emulations are great in that I can have my fav calculators with me no matter what the circumstances.
Problem with the emulations are you don't get that wonderful HP beveled keypad. :(
I also use Smart BASIC on my iPad to test out simple routines quickly.

That's what I use at work ;D
well, it does what it is build to do, and I like it a lot.
Yes, I'm an accountant, and yes, I use Excel too :DD

TI 89.... Sadly most my calculations needed can be done by Chrome.

HP 28S, used it nearly every day since my college days in the 80's... Can't use a "normal" calculator any more.

Only a few years late, but still...
calculator apps fall short, touch screen is rubbish, give me actual buttons for doing quick calculations at the bench. My opinion is graphing calcs are dead. If I'm needing graphing, give me scilab or [insert favorite math package here].
TI83 plus was a decent easy to use calculator (well, back when I was in highschool, I'd say it's suitable for highschool students, but probably not college), then I got an hp 49g+ in college, and let me tell ya, that thing was the pimpslappin', featherinthehat wearin', boss of the graphing calc game. Algebraic or RPN, at least twice as fast as the TI89 or 92 (maybe 3 or 4 times faster). The real gem was the beautifully easy way to switch between rectangular and polar. I was able to breeze through the arithmetic drudgery of calculating phasors in circuits class, much faster than my friends with their ti83's. But alas, that got donated to the ether when I lost it at a coffee shop a few years back..
Great thread though, I'm looking for a nice, small rpn calc for quick basic calculations. Quick and easy is key, using the pc or smart phone is just too cumbersome. I have lots of suggestions from here now. Thanks everyone.

I use a TI nspire. It's way overkill for what I need, but I got it for like $10 on ebay to replace my TI84 with broken keys.

One of my first calculator was a Commodore. I don't recall the model number but I do remember that it was possible to program it. Nothing excessively fancy but for the early 70's, this was more than the regular and limited calculators available during these years.
Before college, we weren't allowed to use calculators at school, but sliding rules were accepted. My dad was an engineer and he explained me how to use it. Honestly, I was really good with that thing. Today I'm looking at one and don't have the fuggiest idea how to use it. It looks like some memory types are volatile, right ?
Early 80's I used my trusted TI59 programmable calculator, with which you could store and recall programs and data using small magnetic cards. I even bought the thermal printed on which the calculator was locked with a key. What a nice toy that little thing was. I used it for many many years.
In the early 2000's I got a TI84 Plus. Never really liked the display on it, but for the price I paid for it, it was more than OK.
The last one I bought, roughly 3 years ago, is a TINspire CX CAS. That little beast rocks. Not lighting fast, but quite good for my needs. If someone is knowledgeable enough with the LUA programming language, he/she can do really neat tricks.
Overall, the TI84 Plus and the TI Nspire CX CAS are the two calculators I'm actually using for my daily needs.

Sharp EL520W
(http://calculatorsforsale.weebly.com/uploads/6/1/4/0/6140015/3210172_orig.jpg?124)

Sharp EL520W
It's 2 gen old version of the international Casio Fx82...
Think 20 year old tech...
The non educational version is now the 995:
(http://www.ecasio.co.jp/img/goods/5/fx995ESN.jpg)
That can be put in "linear mode" for those VPAM hatters ;)
Edit:
Casio still sells in Japan the 20 year old version!
casio.jp/dentaku/product_list/products/?m_no=338 (http://casio.jp/dentaku/product_list/products/?m_no=338)
(http://productsearch.casio.jp/dentaku/images/products/fx72F_L.jpg)

I've had a HP22S for many years. It's NOT RPN. I don't know if they ever made a newer version to replace it.

I've had a HP22S for many years. It's NOT RPN. I don't know if they ever made a newer version to replace it.
I am pretty sure there was only one version of the HP22S
Here is a picture of the one I have with serial number: 3038S06339
This one and the HP32SII are always on my engineering table.
For some calculations I prefer the RPN and for others I take the normal route with the 22S.

My first scientific calculator, used in HSC (Form 6, or now called year 12) in 1976. It was cheap at the time  today's equivalent of about $800. Quite collectible these days and very, very rare. Also sold under "Abatron 808". Apparently it was developed in 1973, which I doubt.
The Farad was unique to Australia because it was badge engineered by Farad Trading Pty Ptd in Balaclava in Melbourne, Australia but was actually made in Hong Kong.
Four buttons have discoloured over the years, but others have not. I don't know why.
The calculator came with two 80mAh nickel cadmium rechargeable batteries at a time when rechargeable batteries were almost unheard of. Those batteries lasted up until 1998, a remarkable 22 years.
I still use this calculator! Although I prefer RealCalc on the Android phone for general use.

I use a TI Voyage 200, for both my school work and my hobby as well. Has a big display for the long equations, or playing Snake or Tetris in Geometry while the Sub yaks away. :DD

Still using the same Sharp EL512 that I got when I was in school (80's).
http://mycalcdb.free.fr/main.php?l=0&id=4330 (http://mycalcdb.free.fr/main.php?l=0&id=4330)
McBryce.

Another vote for the HP42s. I have a real one as well as an emulator on my phone and my PC.
It is fast (the later HP graphical calculators were dog slow), it has just the right level of automation and features for engineering calculations.
Free HP42s emulator: http://thomasokken.com/free42/ (http://thomasokken.com/free42/)
(https://i.imgur.com/QnNyM3G.jpg)

I opened up my 1976 calculator to fix a dodgy keyboard contact. I found this this chip: A Rockwell A4001PC.
I cannot find any data on it on the web. I would love to know what goes on inside, what algorithms it used. Rockwell is useless... they have no data on a chip they produced in 1975. One reason to keep old databooks.
If anyone has a datasheet on this chip from an old Rockwell book. I would very much appreciate it.
From what I can gather, it is designed to drive the low level VFD display, does all the normal and trigonometric functions and key board decoding and probably debouncing.

Made by Rockwell for many different manufacturers, including Casio, Olympia and others who were after a basic calculator. As you say, basically does everything including keyboard ( using the digit drives as scan lines), display driving and contains a 4 bit 4004 core, some ROM ( IIRC 8k), around 128 bytes of register ( shared RAM, stack and register space) and a high voltage ( 40V process) NMOS design, to do the display driving. Only thing it needs are a external set of supplies, 20V for the display and substrate bias, and around 6V for the logic, all provided by the DC/DC converter spread on the left side of the board.
Sorry, not in any of my databooks, but you might look at calaculatormuseum for other models using the same chip and see if you get any joy, though they were a mask ROM with slightly different code for each model, though in most cases the only difference in models was the extra keys being installed in the unit to provide the functions. You might want to look up how HP did the original HP calculators, they used a chipset that was second sourced by Rockwell and later consolidated into the single chip used here. Similar methods used for the operations in all of them.

Made by Rockwell for many different manufacturers...
Thanks! Very interesting info. I looked up the Intel 4004. The world's first microprocessor. Developed in 1971. This calculator was built in 1975, although the A4004PC was developed in 1973. A brilliant little chip with PROM on it, no external XTAL either. It appears the source code is non existent. It would be lovely to find that.
In those days, calculators had a wow factor. Even in uni we all had fun with our calculators. THey were like jewelry, to be admired. I preferred TI, rather than HP, but around 1977 some terrific calculators were born by these companies and they cost a mint.
These days noone cares how a calculator works, especially the mobile phone gamer kiddies. No wow factor in it for them.
My calculator is 40 years old. The 2,300 transistors in the micro are still working strong. The capacitors are still OK.

I use HP41CX both physically and emulated on the Smart phone. Also use HP12C again the real thing and emulated. The emulations are great in that I can have my fav calculators with me no matter what the circumstances.
Problem with the emulations are you don't get that wonderful HP beveled keypad. :(
You are absolutely correct about losing the access to beveled HP keypad. For the past six months now I've been exclusively using the AL Software i41cx emulation on an iPad Air 2 with the Apple Smart Cover. I use this config so I can have it in constant ON mode with the cover holding it at a really nice slant horizontal position. Other times, while using the Pad ( I use it a lot) I just poke the icon and POW my 41cx is right there in vertical.
At first it was a little odd touching glass instead of the HP keys with that satisfying click feedback. However, after awhile I got to like the emulation As much as and in some cases even more than the physical calculator. First, the emulation is always with me and it's clean and bright and never gets old. I've been buying old CX's off Ebay and using them a lot and owing two so that when one gives out I have a back up. Getting those N batteries is a cost and a nuisance. Next, the emulation has MUCH MORE functionality. In horizontal mode, I have two screens, one being the calculator face that is much easier to see and read that a phisical unit and the other a screen that you can swipe and see ALL the register or ALL the User flags or other things. Also, the iPad version is big and bright and functional and easy to read and will never go bad. I no longer have the fear of not being able to get a good replacement.
After using the emulation for about 30 days I no longer missed the physical keyboard. In fact, I haven't taken the actual calculator out of its case for six months and i just think I need to check on the old calculators and change the N batteries so they don't leak.
I never thought some iPad version would give me the satisfaction of or replace my old trusted CV's and CX's, but it has.
Incidentally, I have no connection to the software, app creator or to Apple. Simply a user.
I also use Smart BASIC on my iPad to test out simple routines quickly.

My Dream Calculator is either the Curta I or the Curta III.

My Dream Calculator is either the Curta I or the Curta III.
You made me look it up! now I want the poster :)

I don't use this guy for calculations, but he's a wonderful clock in my room.
I found him last year, repaired him and replaced his batteries. The first words I heard from him was that it was "...1982 today". That sent shivers down my spine  did this calculator really not know? I was tempted to keep him on his old timeline, but it was easy to convince him that his default reset point was a long time ago. See the attached .flac
I can't remember how far he would believe me to, I think 2099 was this limit. A century past the manufacture date isn't too bad as obsolescence goes.

Hi,
When I use a real calculator I use a HP41CV or CX (I have a few). These were introduced in 1979. In 1979 they were $295.00 and $325.00 USD. Around $1000.00 if you adjust for inflation. It is a good job they last :D
They run of four N cells. N cells are 12 mm diameter x 30.5mm long. The batteries last many years.
Most of the time I use an emulation than runs under Windows. The emulation can be downloaded from here:
https://www.educalc.net/326089.page (https://www.educalc.net/326089.page)
Here is a screen shot:
(http://www.eevblog.com/forum/chat/whatcalcultatordoyouuse/?action=dlattach;attach=164685;image)
There is much more information here:
http://www.hpmuseum.org/hp41.htm (http://www.hpmuseum.org/hp41.htm)
And a teardown by Dave:
http://www.youtube.com/watch?t=1114&v=mGFJQxAbWeY (http://www.youtube.com/watch?t=1114&v=mGFJQxAbWeY)
Regards,
Jay_Diddy_B
I also have HP11c, HP15C, HP16C, HP35S (relatively new), HP38G, HP48GX and HP97 ;D

For a bit more stuff about HP 41 check out this site
http://www.hp41.org/Intro.cfm (http://www.hp41.org/Intro.cfm)

Nonprogrammable: Casio FX115ES PLUS
Programmable: TI nSpire CX CAS (can compute matrices with complex entries :D)

Me too, I have the Radio Shack EC4014, which is the exact same calculator as the Casio FX115.
Its amazing that it still works! I still have the manual for it too.
Quote from: RCMR on 20120417, 01:59:08 (http://www.eevblog.com/forum/index.php?topic=7934.msg104969#msg104969)I still use the old Casio FX115 I bought way back in the 1980s.
Does multiple base math and is solar powered.
I'd rather have something that handled RPN but the Casio is what I have.

I use the HP Prime.

I have a WP34S (because it's fun), HP35S (nice recent RPN, good for confusing the kids), Casio fx991ES (because it's like the kids fx85S they are asked to use at school) and a Casio fx4200P (because I'm too sentimental to part with it) on my desk.
I tend to use Excel or Wolfram Alpha. :DD

FX100AU plus, but only because our school has a list of approved calculators.

I use the HP Prime.
How do you like it?

Ti84 plus

Great thread though, I'm looking for a nice, small rpn calc for quick basic calculations. Quick and easy is key, using the pc or smart phone is just too cumbersome. I have lots of suggestions from here now. Thanks everyone.
https://www.swissmicros.com/ (https://www.swissmicros.com/)

For 30 years I carried an FX98 as my goto Casio until I found out it was rare, and losing it would be irreplaceable, if not terribly expensive. So several years ago, I loaded up on FX260s and leave the FX98 at home.
I last saw an FX98 sold on eBay for over $300.
For Casionuts:
http://www.casiocalculator.com/Download/Collectors/CasioCollectors.html (http://www.casiocalculator.com/Download/Collectors/CasioCollectors.html)
I sold my BROKEN Casio CFX400 scientific calculator watch for $400 cash to someone in the US before the whole ebay collecting craze took off.
That model is worth even more now, up into the 4 figures for a watch that I paid $20 for at KMart back in the 1980's.
Dave.
Crap, I am going to have to go dig through my high school boxes at my parents house.

Bloody hell. I've got one of them as well somewhere!

My first and all time favorite RPN was the HP 48SX. From time to time I use HP 15C LE and the fully self resaturated HP 97 on my desk. ^^
It's also very handy to have them 1:1 on my touch devices with me.
Non RPN calculators always confusing me. O

An actual HP11C and I use the RealCalc app (pictured) in RPN mode on my Android phone.

Still my old TI89.
https://www.swissmicros.com/ (https://www.swissmicros.com/)
Ooooh... salivating

I never had a 41CX. I went from TI 57 to HP 28S in 1986, which I still use today.
Though frankly, most often now my "calculator" is google. You can do all kinds of things from the google search bar, including any kind of unit conversions, decimal/hex/binary, up to the minute (nearly) foreign exchange rates
Being able to copy&paste from or to what you're working on, rather than enter again on a physical calculator, is a huge timesaver.
Enter: 9.8 m/s^2 * 3 s
Google: 29.4 m / s
Enter: 9.8 m/s^2 * 3 s in km/h
Google: 105.84 kilometers per hour
Enter: 100000 aud/year in rubles/month
Google: 358 043.617 Russian rubles / month
It's pretty useful.
If it's more repetitive/complex then my calculator is OOcalc or ruby/perl. Hmm.. or actually I use elisp for quick calculations a *lot* too. All depends on what is handy and convenient at the time.

TBH I'd use s spreadsheet more if someone did one that did engineering units.

HP48SX, X48 and Droid48

Enter: 9.8 m/s^2 * 3 s
Google: 29.4 m / s
Enter: 9.8 m/s^2 * 3 s in km/h
Google: 105.84 kilometers per hour
Enter: 100000 aud/year in rubles/month
Google: 358 043.617 Russian rubles / month
It's pretty useful.
Instead of using google for this, try Wolframalpha
https://www.wolframalpha.com/ (https://www.wolframalpha.com/)
It gives you even functions and so much more

Enter: 9.8 m/s^2 * 3 s
Google: 29.4 m / s
Enter: 9.8 m/s^2 * 3 s in km/h
Google: 105.84 kilometers per hour
Enter: 100000 aud/year in rubles/month
Google: 358 043.617 Russian rubles / month
It's pretty useful.
Instead of using google for this, try Wolframalpha
https://www.wolframalpha.com/ (https://www.wolframalpha.com/)
It gives you even functions and so much more
Of course I know alpha. For things like the above it takes about six seconds where google is under a second. HUGE difference. Not worth it unless it's something google can't do.

Still have the HP 48G  from time when studying to telecomm engineering :)

Yep, google is now really handy for that sorts of things. Using it myself at times.
On the otherhand it takes (according the 2011 figures) 2000 watts of power (peak average) to make a one search on it (Calculated with HP50g and its units functionality).
Not so nice if you are conserned about environmental impacts (which everything naturally does). It would be nice to know the whole energy impact (your machine, networks infrastructure and end server and the result coming back along the network infrastructure) of these kinds. Well the unit & calculator functionality is propably a lot less as there is not huge database search involved.
Enter: 9.8 m/s^2 * 3 s
Google: 29.4 m / s
Enter: 9.8 m/s^2 * 3 s in km/h
Google: 105.84 kilometers per hour
Enter: 100000 aud/year in rubles/month
Google: 358 043.617 Russian rubles / month
It's pretty useful.
Instead of using google for this, try Wolframalpha
https://www.wolframalpha.com/ (https://www.wolframalpha.com/)
It gives you even functions and so much more
Of course I know alpha. For things like the above it takes about six seconds where google is under a second. HUGE difference. Not worth it unless it's something google can't do.

Yep, google is now really handy for that sorts of things. Using it myself at times.
On the otherhand it takes (according the 2011 figures) 2000 watts of power (peak average) to make a one search on it (Calculated with HP50g and its units functionality).
Not so nice if you are conserned about environmental impacts (which everything naturally does). It would be nice to know the whole energy impact (your machine, networks infrastructure and end server and the result coming back along the network infrastructure) of these kinds. Well the unit & calculator functionality is propably a lot less as there is not huge database search involved.
Enter: 9.8 m/s^2 * 3 s
Google: 29.4 m / s
Enter: 9.8 m/s^2 * 3 s in km/h
Google: 105.84 kilometers per hour
Enter: 100000 aud/year in rubles/month
Google: 358 043.617 Russian rubles / month
It's pretty useful.
Instead of using google for this, try Wolframalpha
https://www.wolframalpha.com/ (https://www.wolframalpha.com/)
It gives you even functions and so much more
Of course I know alpha. For things like the above it takes about six seconds where google is under a second. HUGE difference. Not worth it unless it's something google can't do.
2 kW? Seems reasonable for a decent server.
If you type those formulas into the address bar of Safari or Chrome you'll see the answer liveupdating as you type, with a delay of maybe 100  200 ms. So 2 kW for that time is 4000 J of 0.001 kWh (both answers obtained by live typing in my Chrome address bar). So that's something like a fortieth of fiftieth of a cent.
I'll take it.

I checked my desk now and found two (!) Casio fx82MS and one HP35s,
in my phone the app realCalc is used and i also have the R&S dB calculator app, highly recommended :+

I use a Casio fx991ES most off the time. I also have my first calculator that could do BASEN, a Casio FX4000P. Using BASEN on the 4000 takes les keypresses, function is less hidden. Overall the 4000P is a very nice calculator to work with.
(https://drive.google.com/uc?export=download&id=0Bxpcl1OprwA3OEo0OHh0djlBM2s)

I had an FX4000P when I was at university. Lovely calculator

Another calculator I have, is Casio FX4500P. Havent used it long time, might be better to find new owner for it... Needs battery replacement, othervise ok (does not have plastic flip covers)

...
2 kW? Seems reasonable for a decent server.
If you type those formulas into the address bar of Safari or Chrome you'll see the answer liveupdating as you type, with a delay of maybe 100  200 ms. So 2 kW for that time is 4000 J of 0.001 kWh (both answers obtained by live typing in my Chrome address bar). So that's something like a fortieth of fiftieth of a cent.
I'll take it.
Hah, I think it is changed since I last time used it, now with drop down menus and everything .. and it seems to be a local process, not a server side functionality. O I did pull the plug to see. ;D

I use a Casio fx991ES most off the time. I also have my first calculator that could do BASEN, a Casio FX4000P. Using BASEN on the 4000 takes les keypresses, function is less hidden. Overall the 4000P is a very nice calculator to work with.
My only complaint about the HP48g and HP50g is that using them with hexadecimal is a pain. I would not mind a more programmer oriented version.
At some point I had a TI55II which I replaced during early high school with a TI66 which I still have. Then Casio's FX7000G came out which led to a funny story. My friend Mike made me aware of it and I thought, "I have got to get that." So that night I arranged to travel across town to BEST to buy the last one they had. The next morning Mike tells me that he had planned on picking up the last FX7000G available locally but some jerk beat him to BEST by about half an hour.
Later I moved to the HP48g with RPN and never looked back although I still have my TI66 and a couple of LCD TI35 derivatives stored with my slide rules for emergencies.

I use a Casio fx991ES most off the time. I also have my first calculator that could do BASEN, a Casio FX4000P. Using BASEN on the 4000 takes les keypresses, function is less hidden. Overall the 4000P is a very nice calculator to work with.
My only complaint about the HP48g and HP50g is that using them with hexadecimal is a pain. I would not mind a more programmer oriented version.
At some point I had a TI55II which I replaced during early high school with a TI66 which I still have. Then Casio's FX7000G came out which led to a funny story. My friend Mike made me aware of it and I thought, "I have got to get that." So that night I arranged to travel across town to BEST to buy the last one they had. The next morning Mike tells me that he had planned on picking up the last FX7000G available locally but some jerk beat him to BEST by about half an hour.
Later I moved to the HP48g with RPN and never looked back although I still have my TI66 and a couple of LCD TI35 derivatives stored with my slide rules for emergencies.
The TINSpire has good Hex and other non 10 based decimals options. Worth spending 10 minutes leaning how it's done.
As for the Google option, it's nice when you have it, but on site, with dodgy internet, not so good.
And if management caught us doing work calculations (fuel usage, fill rate, efficiency of x etc) on something that is not secure, like Google, not so good...
I still wish a manufacturer had an "unlimited version" of their top of the range CAS calculators with none of the educational shackles left. I think the HP 50g was the last of those.
Personally, while I do have a CAS app on my Iphone, I do find that a single purpose tool works better for me, less farting around.

As for the Google option, it's nice when you have it, but on site, with dodgy internet, not so good.
Anything remote like Google or Wolfram Alpha is too slow and getting slower all the time. I get by with Mathematica sometimes but that is local and even that is too slow unless it is already open and ready.
Plus RPN has a time saving stack.

I use a Casio fx991ES most off the time. I also have my first calculator that could do BASEN, a Casio FX4000P. Using BASEN on the 4000 takes les keypresses, function is less hidden. Overall the 4000P is a very nice calculator to work with.
My only complaint about the HP48g and HP50g is that using them with hexadecimal is a pain. I would not mind a more programmer oriented version.
At some point I had a TI55II which I replaced during early high school with a TI66 which I still have. Then Casio's FX7000G came out which led to a funny story. My friend Mike made me aware of it and I thought, "I have got to get that." So that night I arranged to travel across town to BEST to buy the last one they had. The next morning Mike tells me that he had planned on picking up the last FX7000G available locally but some jerk beat him to BEST by about half an hour.
Later I moved to the HP48g with RPN and never looked back although I still have my TI66 and a couple of LCD TI35 derivatives stored with my slide rules for emergencies.
The TINSpire has good Hex and other non 10 based decimals options. Worth spending 10 minutes leaning how it's done.
As for the Google option, it's nice when you have it, but on site, with dodgy internet, not so good.
And if management caught us doing work calculations (fuel usage, fill rate, efficiency of x etc) on something that is not secure, like Google, not so good...
I still wish a manufacturer had an "unlimited version" of their top of the range CAS calculators with none of the educational shackles left. I think the HP 50g was the last of those.
Personally, while I do have a CAS app on my Iphone, I do find that a single purpose tool works better for me, less farting around.
If the 50g has a manual as good as the 48S(X) then you are right. A user and prog. guide for the 50g in 48S(X) style needs maybe 5000 Pages. ;D
In my opinion the 48G(X) was the first step backwards. Keyboard material and colors, documentation quality, pop up menu system, etc. are not as good as the older ones. But that's history. The last calculator withdrawal areas are schools and collectors. Kids grow up with smartphones and every other thing has a cpu in it to calculate its needs. I am a little collector. ;D
@Rolo: What was the problem with hexadecimal? You can configure the user keyboard or write little programs for your needs. The 48 UI is as flexible as a unix shell. And with some stack enhancement libraries even the old 48S(X) is fast enough for every need. But that's another story...

At the high school I had a Casio fxd400 first, and a Casio fxp401 later. They are both stolen to me. The first at the high school, the second at the university. They was the best calculator of ever for me. I'm still looking for them on ebay from time to time.
(http://www.casiocalculator.com/Museum/Calculator/FX/FXD400/CasioFXD400front.jpg)
(http://www.casiocalculator.com/Museum/Calculator/FX/FXP401/CasioFXP401front.jpg)

Its fairly rare for calculators to be updated so I was surprised when I saw this at a Walmart, and $7.
Full review:
https://edspi31415.blogspot.com/2017/03/reviewcasiofx260solariifx82.html
(https://2.bp.blogspot.com/iP1rzg4e0C0/WNpbj0dIOSI/AAAAAAAAFKE/ZS80Ox4PfecUZIkkBL9e3wowTUBRdjmCgCLcB/s1600/Comparison.jpg)
Unfortunately, choosing a calculator is a touch complicated if you're in school.
For general purpose electronics use, any scientific calculator will do. I like the Casios, FX 260 is as close to ones I used heavily in school in the 1980s [ older Casios are more durably made and keys laid out better, I still use my 30+ year old college Fx100 today].
This is really for bench fixups, back of napkin designs or estimates. Portability, maintenance free, and low cost are most important, this is about $8 at Walmart or $11 at Amazon, fully solar no batteries. Its very light too, and wont' load your shirt pocket, so I have 3: one in the lab, one in my work bag and one in the living room:
(http://ecx.imagesamazon.com/images/I/51OU5gwGUL._SL500_AA300_.jpg)
For just $13 more you can get another with gobs of added functions, even graphing, but it also makes the calculator bigger, adds more keystrokes, and hard to shirt pocket.
You don't really need more than ~ 8 bit accuracy for making back of envelope calculations. if you need to do more complex or accurate calculations, its best to use a PC so the outputs are fed into SPICE or other simulator, has superb graphing, and the free Windows calculators provide all the basics. Also if you track calculations with a 'paper tape' on a PC its far easier to manipulate.
For school, learning math concepts and being that some classes do not allow you to use a PC, PC provides far better graphing capabilities, you have to go with what the class recommends.

Last acquisition for the collection: an HP 35s. Pretty well made calculator and has 40 bits for my Hex calculations. This is an excellent companion for my HP 48GX (which stays at home).