Casio CFX-400c scientific calculator watch

[Johnboy]

While I'm not exactly sure where to put this... I've always wanted one of these. It came as a complete shock to me tonight to realize that the guy who started this site is the designer of the uWatch. I couldn't understand why manufacturers don't seem to be interested in developing a new scientific calculator watch. I know, I know... there are a few of them available, but they're high end. What I loved about Dave's methodology in presenting his design was the concept of "you want something like this that badly? Alright. Build it yourself." I really wanted one of those kits and even sent him an email about them (this is quite a long time ago, of course, when he was presumably less busy), and he told me that he'd moved on from it. Obviously, he has.

My question to you is this: How many of you would use (were it readily available) a wristbound calculator with all the functions you'd expect from your scientific pocket calculator, or your phone app moonlighting as one? Am I alone in imagining that there's a hole that needs to be filled here, and not just the one in my mouth for my shoe to fit into?

[EEVblog]

AFAIK Casio still make an almost identical case for a databank calc watch. It would take them much to redo the CFX-400 surely?

I've always want to try a re-purposing project for this.

Maybe start a petition to send the Casio?
Would they make it if say 50,000 people were interested?

EDIT: Now searching Linkedin for a suitable contact... 

[EEVblog]

My question to you is this: How many of you would use (were it readily available) a wristbound calculator with all the functions you'd expect from your scientific pocket calculator, or your phone app moonlighting as one? Am I alone in imagining that there's a hole that needs to be filled here, and not just the one in my mouth for my shoe to fit into?

No, you are not alone, I think there would be a huge market for it if implemented correctly. It anything just for an anti-smart watch appeal.

[EEVblog]

These dudes look approachable 

https://www.linkedin.com/in/joseph-gillio-7789275/

https://www.linkedin.com/in/robert-prunk-9429882/

[Johnboy]

I am thrilled to hear that you are supportive of a "petition" of sorts, Dave. Surely I can't be the only kid who ever wrote a letter to Casio and asked "what gives"?

I think you're right about the backlash regarding the "smartwatch phenomenon". My first question upon seeing one wasn't whether I could give it voice commands to start my car, but whether it had a pi key.

[Ampera]

I'd buy one if it had an RPN option.

[floobydust]

Dear God, I have the original bought in 1993 and a few years ago purchased another (new) one to replace it.
Casio was still making them, although slightly different LCD and internals.


I lost a job interview because I was wearing it.
Interviewing manager said "I noticed your watch, you must be very detail-oriented and calculating" 

[rsjsouza]

I absolutely love these old watches, but I just don't see a use for a full scientific calculator on the wrist... I could buy one if the price is right (which is what obviously matters to Casio).

[2N3055]

If we could pressure Casio to restart production of something old, I would vote for old calculator fx-61F
I don't know what I'm going to do if mine dies..

[Johnboy]

I lost a job interview because I was wearing it.
Interviewing manager said "I noticed your watch, you must be very detail-oriented and calculating"

Of course. That's the kind of manager I'd want running my company when I wasn't around. I'd rather have sloppy, vapid employees any day. Sigh.

If we could pressure Casio to restart production of something old, I would vote for old calculator fx-61F
I don't know what I'm going to do if mine dies..

I might recommend the TI-36X Pro. The only fault I've found with it is that it's too large to mount on my wrist.

I absolutely love these old watches, but I just don't see a use for a full scientific calculator on the wrist...

I foresee any number of AP high school and college students who might forget to bring their calculator to a test, but would be much less likely to forget their watch (taking into consideration that cellular phones often aren't allowed). It would certainly make a good gift as a backup from those parents and grandparents who used their watches, not their phones, to tell the time.

I could buy one if the price is right (which is what obviously matters to Casio).

My point exactly. Certainly this thing could be more cheaply manufactured now. That's why I don't understand why no one has jumped into this niche.

I'd like to respectfully ask the moderators, considering my regrettable lack of foresight in the matter and relative novelty around here as a posting member of this forum, to consider moving this thread to a different section where we might get a larger sampling of views from forum members (for example, "Products" or even "General Chat"). I ask this because  A) I'm not at all certain that a discussion of a discontinued calculator watch (or, especially, petitioning for a future model!) necessarily belongs in the "Vintage Computers" section, and B) because I feel strongly enough about this topic that I'd like more people to notice the option to weigh in with their opinions and information.

[rsjsouza]

I absolutely love these old watches, but I just don't see a use for a full scientific calculator on the wrist...

I foresee any number of AP high school and college students who might forget to bring their calculator to a test, but would be much less likely to forget their watch (taking into consideration that cellular phones often aren't allowed). It would certainly make a good gift as a backup from those parents and grandparents who used their watches, not their phones, to tell the time.

Perhaps you may be right, although I suspect younger audiences simply don't use wristwatches as much as folks of our generation...

I could buy one if the price is right (which is what obviously matters to Casio).

My point exactly. Certainly this thing could be more cheaply manufactured now. That's why I don't understand why no one has jumped into this niche.

My impression is that he electronics are not the costly thing anymore, but instead the machining and the assembly to put all this into the form factor of the wristwatch.

[Muttley Snickers]

I'd like to respectfully ask the moderators, considering my regrettable lack of foresight in the matter and relative novelty around here as a posting member of this forum, to consider moving this thread to a different section where we might get a larger sampling of views from forum members (for example, "Products" or even "General Chat"). I ask this because  A) I'm not at all certain that a discussion of a discontinued calculator watch (or, especially, petitioning for a future model!) necessarily belongs in the "Vintage Computers" section, and B) because I feel strongly enough about this topic that I'd like more people to notice the option to weigh in with their opinions and information.

You as the original author of this thread have the ability to relocate it to almost any part of the forum you see fit, have a read of the thread linked below for guidance and instructions.   

Moving Topics.
https://www.eevblog.com/forum/blog/what's-this-move-topic-icon-all-about/

[EEVblog]

Dear God, I have the original bought in 1993 and a few years ago purchased another (new) one to replace it.
Casio was still making them, although slightly different LCD and internals.

Where did you get a new one? That would fetch probably $1000 on ebay!

[EEVblog]

If we could pressure Casio to restart production of something old, I would vote for old calculator fx-61F
I don't know what I'm going to do if mine dies..

I'd love to do an EEVblog branded version of the FX-61F!

[EEVblog]

https://www.linkedin.com/in/robert-prunk-9429882/

I have his direct email 

[2N3055]

If we could pressure Casio to restart production of something old, I would vote for old calculator fx-61F
I don't know what I'm going to do if mine dies..

I'd love to do an EEVblog branded version of the FX-61F!

If you do I would like serial number 00001 :-)

I would actually buy two, one for me (backup to the one I have) and one for my son...
People that don't have it, don't understand the genius of built in impedance mode....
And a parallel operator...

So yes you have my vote!!

Regards,
Sinisa

[bd139]

Sign me up for one watch and one FX-61F

There is the possibility of repurposing HP's calculator line as it's just an ARM7: https://en.wikipedia.org/wiki/HP_30b

Edit: the new FX-991 EX is pretty good. You can turn off all the shitty entry functions and use it as an engineering calculator. has solver, engineering units, conversions, constants, base-N and the display isn't shit. If they do a programmable one I'm going to be all over it like a seagull on chips.

Edit again: For ref, the OEM for most of the calcuators from Casio, Sharp, HP, TI etc these days is Kinpo: http://www.kinpo.com.tw/English/

[EEVblog]

Edit: the new FX-991 EX is pretty good. You can turn off all the shitty entry functions and use it as an engineering calculator.

It still has that VPAM entry rubbish

[EEVblog]

There is the possibility of repurposing HP's calculator line as it's just an ARM7: https://en.wikipedia.org/wiki/HP_30b

IIRC one of the guys who wrote that firmware also re-wrote my uWatch code to play chess and do other stuff.

[bd139]

Edit: the new FX-991 EX is pretty good. You can turn off all the shitty entry functions and use it as an engineering calculator.

It still has that VPAM entry rubbish

You need that for solver expression entry. Compromise really.

[EEVblog]

Edit: the new FX-991 EX is pretty good. You can turn off all the shitty entry functions and use it as an engineering calculator.

It still has that VPAM entry rubbish

You need that for solver expression entry. Compromise really.

Sure it's great for that, but otherwise a PITA for everyday calcs. It can't even figure out that 2 EXP 3 (-) means 2 milli, you have to use the correct order of 2 EXP (-) 3
The original Casio's are smart enough to work both ways.

[Ampera]

The HP Prime has some of the best data entry I've seen on a calculator. It's actually better in some ways than a proper PC CAS, considering you have dedicated functions for everything, and the 400mhz puts it above anything that Ti has to offer.

[bd139]

Edit: the new FX-991 EX is pretty good. You can turn off all the shitty entry functions and use it as an engineering calculator.

It still has that VPAM entry rubbish

You need that for solver expression entry. Compromise really.

Sure it's great for that, but otherwise a PITA for everyday calcs. It can't even figure out that 2 EXP 3 (-) means 2 milli, you have to use the correct order of 2 EXP (-) 3
The original Casio's are smart enough to work both ways.

That’s not really an issue for every day calcs. It makes a difference which way round you write it on paper as well.

[2N3055]

Slightly off topic but.. it just occurred to me, that if we had member with name LM723 , three of us would make fine PSU :-)) LOL

Beauty of the fx-61F is it's impedance mode and dedicated capacitor, inductor, parallel buttons, together with
unit suffixes. I type into it directly from schematic..... It is very quick...

[bd139]

Hahaha

I had an HP50g for a while. I programmed those buttons with RPL as soft buttons on F1-F6. Problem solved. Really barely used it past that so the Casio got the job in the end because I can remember how to use it every time I pick it up. Excel is pretty good at crunching numbers otherwise which mainly amounts to tweaking for me.