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Full Version: CASIO fx-1000 Scientific Calculator -I believe this one is highly collectible
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I believe this is one of the hardest models from Casio to acquire these days (2017), as there is little reference about it and it is very hard to find one for sell in the major auction sites.

My unit was made in 1977 in Japan. This one could not be made earlier because some components have date codes from 1977.

This is a really pocket sized machine from mid 70's, measuring just 67x128x14mm and weighting less than 100g. Operated by a single 1.5V AAA sized battery with an average current consumption of just under 6mA (0.085Watt).

I found a couple of CASIO adverts in the Internet (mainly published in New Scientist, 1977), where this model is shown side by side with other CASIO models like the fx-21 (my first owned calculator, ever), the fx-201P and the PRO FX-1.

I like the marketing messages from these old days. CASIO in its own words:

"CASIO to be precise", "These will take a weight off your mind".
"The higher your daily maths, the deeper your daily drudgery ...escape with Casio's way-ahead new Scientifics!"

"The unique FX1000, just 3.3 ounces of shirt-pocket scientific wizardry."
"Fantastically slim and light, yet strong and lastingly accurate."
"Built-in programme functions simplifies standard deviations."
"Direct fractions. Independednt memory, Single touch Pi entry"


[Image: Casio_fx-1000_001.jpg] [Image: Casio_fx-1000_003.jpg]

This unit works fine, but the LCD is defective.
Anyway, I know that these first or second generation LCD modules, using yellow UV filters, would not last 40 years maintaining the same original pristine working condition.

This unit suffered several injuries during its long life. Battery leaking corrosion was probably the first issue, then a back cover was broken and the power switch is missing (most probably resulting from inadequate handling by someone trying to fix the battery leaking damage).

[Image: Casio_fx-1000_002.jpg]


Typical 70's style keyboard. Double injection molding plastic keys were common in those days.

[Image: Casio_fx-1000_005.jpg] [Image: Casio_fx-1000_006.jpg]



Capacitors from Elna and Rubycon - Two of the best Japanese capacitor brands along with Panasonic.
Processor from Hitachi HD36285 7B 31 (1977 February date code)
The power supply module (brown color PCB at the left side) uses a 2SD655 6K3 transistor (1976 date code).

[Image: Casio_fx-1000_007.jpg] [Image: Casio_fx-1000_009.jpg]


Defective LCD display. Made by EPSON (1976 date code).
EPSON model LD-302
Shinshu Seiki Co. Ltd.
Made in Japan Pat.
Manufacturing code: 6N4C

[Image: Casio_fx-1000_010.jpg] [Image: Casio_fx-1000_012.jpg]


Power supply module schematics.

[Image: Casio_fx-1000_power_supply.jpg]
My first school scientific calculator was a Casio fx-2000, which was, I think, functionally identical to the fx-1000 but had a more compact, slimline look on account of it being powered from a couple of LR44s. I remember that it cost 24.95 GBP at a technical trade fare that was being held in Harrogate, Yorkshire. At the time (~1977), the LCD Casios hadn't made it to regular retail outlets.

It was certainly the first LCD calculator in my school. The build quality contrasted favourably with the low end Commodore scientifics that were in general circulation.

The fx-2000 is now also a very rare find.
In my work desk drawer, I still have an fx-2000, indeed I treated it to a new set of batteries only a few weeks ago, though more for old times' sake than in expectation of using it in earnest. BTW, it has three cells, not two.

I bought it new in 1977 or '78, when I was working on construction of a section of the M25. It was the first LCD scientific I had seen, and the extended battery life by comparison with LEDs meant I could carry it with me all day on site. IIRC, the 1000 and 2000 in the names referred to claimed battery life in hours. I think I paid £30 for it from an office supplies shop in Bromley.

Having spent some years in donkey-jacket pockets, the back plate is a little dented, and the satin finish has worn off the edges and around the switch, but it still works fine. The yellow LCD needs to be at the right angle to be legible, and the numerals are small by modern standards, but I think it's doing well to still be working at almost 40 years old.
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