EEVblog #1093 - Casio FX260 Solar II Calculator Review

[Fungus]

I love the horizontal format of those HP calculators but I've never been convinced that RPN is better.

I'm right there with you on RPN -- Between RPN and standard AES (with order of operations and parentheses), I think it's a wash.

Yep. Both work. I have a preference for AES but YMMV. I'd stay out of any vote/debate on that subject.

I'm not a fan of VPAM

I sort of am when I see the results on screen but not while I'm typing it in.

It's obviously a big deal if you're typing in integrals and complex formulas (which I never do). For ordinary adding and multiplying? It seems more of an impediment than a help. eg. When I press the "sin" key I want to see the sine of the number that was on screen, not the word "sin(".

VPAM peeve: I know you don't have to type closing brackets, I know that the calculator is perfectly happy with "sin(30", but my OCD screams whenever I see it. 

Maybe things would be different if I'd grown up with it.

[rsjsouza]

The one thing these HP vintage calculators have that ticks me off is the "CHS" for "Change signal" - IMHO the + / - symbol is easier to catch the eye when looking for such operation.

You only need to use it twice to learn it. 

Not when this is not your main calculator and the key is immersed among many others with various acronyms. YMMV, though.

eg. If you look at the keyboard of the 1960s HP9100B you can see the same functions, the same "ABCDEF" programming model, the same conditional expressions, etc. as the 11C. I'd be willing to bet the 11C could run a lot of the programs written for the 9100 (assuming they were small enough - the 9100 had optional memory expansions).

Certainly interesting; not only HP but TI used the same model on its first handheld programmable calculator SR-52.

The earlier Olivetti Programma_101 used "VWYZ", but I guess the Italians weren't as trendsetters as the yanks.

Maybe the best way to describe the mode of thinking between RPN and AES is that RPN thinks like a computer works, while AES thinks like math works. VPAM doesn't seem to think at all--it's just "copy the formula from the book".

Even the AES calculators have operations similar to how a computer expects the instructions, especially when using a function that requires a number before it (30 Sin, for example). But I agree with Fungus that VPAM is better suited for visualization, not data entry.

[electronupdate]

For a detailed look at the controller silicon I put up this video:

https://youtu.be/HrsT1v34TH8

[Fungus]

For a detailed look at the controller silicon I put up this video:

Now that's a teardown - right down to extracting the glass from the fiberglass PCB.


(Hope it all went back together OK)

[rsjsouza]

That was a great teardown, electronupdate!

[FrankBuss]

Maybe I should use a real calculator again, looks like calculators on PC gets worse:

[malagas_on_fire]

There are some knockoffs of the fx 991 EX Classwizz. Yeah....

https://ebay.us/U9EZlr

[EEVblog]

There are some knockoffs of the fx 991 EX Classwizz. Yeah....
https://ebay.us/U9EZlr

I wonder if they are an exact clone of the processor and code etc, or just a functional clone. i suspect the later.

[malagas_on_fire]

From the description and  images of the calculator it has less functions, a dual display screen . Good luck on drawing a QR code on that display

[rsjsouza]

Not only that, but the keys remind me of a US$0.49 cheapie on the local store that had terrible rubbery keys that couldn't decently acknowledge keypresses.

[Howardlong]

I am sure I'm not the only one, but I did a list a while ago of what I'd like to see on a calculator as an embedded systems type of a certain age. So, I do both programming and hardware. I'm not looking for anything more than the ability to make quick and basic scalar calculations. For anything more than that, I'll use a spreadsheet or program something up on the computer.

Essential
Hex conversions and basic calculations (easy to use, not some of the half-arsed implementation)
Persistent engineering mode (preferably persistent over a power cycle)
Dedicated single press keys for: 1/x, x<>y, sqrt, x^2, x^y, log, ln, sin, cos, tan, pi
Logical layout
Either immediate execution algebraic or RPN, none of this formula or VPAM nonsense.

Very useful
Dual power (battery plus solar, persistent memories and settings, operates in low light)
Backspace
Direct display and calculation of HH:MM:SS for your timesheets

Nice to have
10+2 display
Conversions (easily accessible)

Mostly useless
Complex (usually just too hard to usefully use)
Multiple memories
Fractions
Programmability
Built in functions (needs a manual)

Useless
Statistics
Probability
HYP function
Constants (often needs a reference card)
Anything that means I need to open the manual

I also did a video, sorry it ended up being about five times longer than I wanted, maybe playback at 1.5x!

[malagas_on_fire]

What about a casio FX 850p which has programming built in ,,, more

FX-5800P

FX 3650P

[malagas_on_fire]

What about a casio FX 850p which has programming built in ,,, more

FX-5800P

FX 3650P

Ooopss the 3650 has the hyperbolic function .... sorry. bad call.

here is the fx 570 spx ii for replace the beaten ti 89 It is the one without solar panel  so it's for AAA nigthtriders  .. off course it had battery inspection

[Howardlong]

I much prefer immediate execution or RPN, none of this new fangled VPAM nonsense! It’s a personal choice of course, biased by what I was brought up with.

As for a programmable calculator, if I’m going to do programming, I’ll do it on the computer. For me, a calculator is for getting small, quick back of the envelope calculations.

Back in the 70s, programmable calculators were a real wonder, I had several. Practically speaking, I have no use for them now, other than for personal interest’s sake and a bit of good old fashioned nostalgia.

The HP Prime for example is an amazing bit of kit, but to be proficient at using it takes very many hours. As an experiment I did do some fairly heavy vector maths on it a couple of years ago, seeing how I got on with it as an alternative to Octave or Matlab. While it certainly worked in this practical use case, I found its biggest drawback is the keyboard entry, not being QWERTY (not to mention a terrible colour choice for the secondary key functions, rendering them unreadable for my old eyeballs). It’s actually easier to use the PC emulator for the HP Prime, but as you’re using a PC, you might as well open up Excel, Octave, or your favourite IDE and hack something together there.

I just use the tool I find most convenient for the job. Personally, I find using Windows’ calculator to be frustrating tomuse in comparison to a desk calculator. I also find calculators on smartphones to be less than optimal, probably due to the lack of tactile feedback from the touchscreen when you’re keying in stuff quickly. That said, if I were to select my favourite useful calculator app it’s HP’s own HP 15C app. Their HP Prime app is pretty good too, but you’ll need to be prepared to spend quality time learning how to use it, and frankly as I mentioned earlier, practically speaking you’re almost certainly better off doing stuff you’d do on an HP Prime on a PC.

[malagas_on_fire]

Even use the bash to calculate is the last resort available  Also i don't like much the windows calculator, and even the galculator on lunix...meh i find myself using my oldest fx 570w and yes its a s-vpam  . I think is the typing in the keys that makes the difference or the abstraction from the computer to the calculator and notebook, handwritting, even with the newer model

[David Hess]

The HP50g is an adequate replacement for the HP48.  My only complaint is that a 75 MHz 32-bit ARM is slower than the 4 MHz 4-bit Saturn because of poor hardware and/or software design.  Battery life is acceptable although lower than the HP48; what makes up for it is using standard AAA cells instead of the embedded rechargeable lithium trash which is common now.

[rsjsouza]

The HP50g is an adequate replacement for the HP48.  My only complaint is that a 75 MHz 32-bit ARM is slower than the 4 MHz 4-bit Saturn because of poor hardware and/or software design.  Battery life is acceptable although lower than the HP48; what makes up for it is using standard AAA cells instead of the embedded rechargeable lithium trash which is common now.

Wow, I didn't know that about the speed. Too bad. I have used the SX and curently have a GX which is a bit faster, but none of them can compare with the emulator I have on my cellphone (although I still prefer to use the calculator itself).

[malagas_on_fire]

Some of the Ti calculators had a linux port since they had ARM processors built-in and hacking available..

https://hackaday.com/2014/11/18/running-debian-on-a-graphing-calculator/

and this was on 2014  imagine now a HP 50 running OpenWRT and framebuffer drivers

[malagas_on_fire]

Check out ANOTHER RIPP_OF FX-991EX Advanced Scientific Calculator 552 FUNCTIONS Count Examination Black 

https://ebay.us/64b35E

She will do it right