Any out there? With maybe just +, -, *, /, STO, RCL?

I'd be ecstatic with a scientific credit card size calculator, I don't care whether it's RPN or algebraic. I've only been waiting, oh 20 years or so...

TRULY SMALL pocket size calculators have sadly never existed.

Dave.

There were a lot of little credit-card calcs back 20 years ago, I saw radio smack version just last week--glued to a clipboard!

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There were a lot of little credit-card calcs back 20 years ago, I saw radio smack version just last week--glued to a clipboard!

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Yeah, but I've never seen a scientific version, they always 4-Bangers.

Dave.

Not RPN, but he may be talking about this one. I still have a radio shack version of this (EC-4009) I got in the mid-80s and wouldn't part with it for the world.

Wow! That is so cool!

The Radio Shack version of the Casio lacked, IIRC, combination and permutation functions. I have the Casio model that you show. These were sold new in 1985. I bought several to give as gifts.

There was an earlier credit card Casio scientific available in late 1978! It is the fx-48. It doesn't have quite as many functions, and it isn't solar powered. It is very slightly smaller. I bought the one I have in January 1979.

In 1983, Casio sold a scientific wrist watch calculator, the CFX-200. It was quite useful, and it isn't much larger than other digital watches. I've still got one, but the calender and DOW function does not work properly after 12-31-1999. Later, a more elegant model in the form of the CFX-400 came out.

So the era of popular, consumer-grade, readily available scientific credit card or smaller calculators arrived more than 30 years ago and vanished more than 20 years ago. I suppose the market didn't support them.

Edited: 9 Mar 2009, 12:59 a.m.

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but the calender and DOW function does not work properly after 12-31-1999. Later, a more elegant model in the form of the CFX-400 came out.

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Set your unit to 1998 and all will be fine (except for the year, of course).

See years matching 2009 if you want to pick a different year.

Or subtract 28 from the year and watch the cycle repeat.

- Pauli

If you carry a mobile phone, another option might be to find an RPN calculator for your phone.

Lygea do a few variations on the 12C, 10B, 10C, 15C etc. for Blackberry and Windows Mobile: http://lygea.com . I have the 12C and 10C on my BB Curve. They've moved the keys around to make better use of the Blackberry keyboard, and some features such as programmability are missing, so it's not truly 'emulated'. Still, it's great just to have an RPN calc with me whenever I need it.

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The Radio Shack version of the Casio lacked, IIRC, combination and permutation functions. I have the Casio model that you show. These were sold new in 1985. I bought several to give as gifts.

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Got mine in high school before I discovered HP. Once my science classmates saw it, several went out and bought them for $12-$15 in '84 or '85, IIRC. Now they show up on ebay now and then for several hundred dollars (almost vintage HP territory). So there's at least some demand for a small scientific like this.

Anyway, thanks for the other info. These are great little calcs. Too bad they're extinct. The only thing I don't like is that dust easily gets in the display/solar panel.

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If you carry a mobile phone, another option might be to find an RPN calculator for your phone.

Lygea do a few variations on the 12C, 10B, 10C, 15C etc. for Blackberry and Windows Mobile: http://lygea.com . I have the 12C and 10C on my BB Curve. They've moved the keys around to make better use of the Blackberry keyboard, and some features such as programmability are missing, so it's not truly 'emulated'. Still, it's great just to have an RPN calc with me whenever I need it.

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Edited: 10 Mar 2009, 4:41 p.m.

I remember my Dad showing me his pocket Casio in response to my HP-15C when I was an undergrad. I didn't remember the exact details, so I asked.

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I still have it. It is labeled "Casio Scientific Calculator fx-88." It is the size of a credit card, 88x59x4 mm. It is light powered: solar, fluorescent or incandescent light. It's probably 20 years old or more. The paint on the cover is deeply scratched. It still works.

Its functions are: x!, x(square) and squareroot; log and ln; 10 the x power; e to the x power; hyp, sin and arcsin; cos and arccos; tan and arc tan); x to the y power and x to the 1/y power; cube root; and statistical functions mean x; sigma n, sigma n-1, sum of x; sum of x squares; random number generator and pi.

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I wouldn't trade it for my 15C, but he really liked it as a replacement for his shirt-pocket sized 6-inch slide rule!

I was surprised that neither Google nor 'the auction site that shall not be named' seemed to know anything about that model Casio.

[self Deleted]

I didn't see comment above concerning the fx-98 or radio shack ec-4009. oops.

Edited: 11 Mar 2009, 7:53 p.m.

Out of curiosity, I just got a volume price on this nice looking Kadio KD-1005 pocket scientific, almost certainly the smallest on the market today.

An amazing US$0.55ea in 8K volume.

Dave.

But its 1cm think. The credit card calcs that I remember were thinner.

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But its 1cm think. The credit card calcs that I remember were thinner.

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Yes, this isn't a "credit card" calc.
As far as I know there has never been a true "credit card" scientific calc. Those Casio's weren't credit card thin either.

A true credit card calculator is one you can slip into your wallet. Only available as 4-Bangers unfortunately.

Dave.

The screen on the iPhone is just a bit smaller than a credit card. So any usable emulator form factor on the iPhone would also work as a credit card calculator. That means I could have a usable 15C or 41CX in a credit card form factor. To fit in your wallet it'd have to have a membrane keyboard. To avoid battery thickness solar would be a plus. Of course BT for I/O. With e-Ink the keyboard could be virtual.

Dave, I think I see your next great project.

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The screen on the iPhone is just a bit smaller than a credit card. So any usable emulator form factor on the iPhone would also work as a credit card calculator. That means I could have a usable 15C or 41CX in a credit card form factor. To fit in your wallet it'd have to have a membrane keyboard. To avoid battery thickness solar would be a plus. Of course BT for I/O. With e-Ink the keyboard could be virtual.

Dave, I think I see your next great project.

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My next project is in next months Silicon Chip magazine :->

The uCurrent

Not a calculator, sorry. But guess where the name came from...

Dave.

Five or six years ago I found a small chinese scientific calculator under the tradename KADIO. About a credit card size, +/- 6 mm thick, landscape form, silver painted plastic (black in the back). With P-R and base convertions capabilities. Despite the tiny keyboard, it was a pretty and cheap toy, so I could not resist and bought it.

It fit nicely and easily in my shirt pocket. In the first day I put it in the pocket, one of the independent silicon keys popped out from the body. It lasted not more than 2 hours of continuous usage before the display fails... Well, the important is that someone has recently produced a credit card size scientific calculator.

I found a Kadio at a kiosko in Chile a couple of years ago. It looked like a 4 banger voyager. I left it on the toy table at an HHC hoping that some genius would find a way to do what this thread is about but no dice. Maybe it fell apart on him after two hours.