CASIO fx-1000 Scientific Calculator -I believe this one is highly collectible

[jebem]

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"



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).




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





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).




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




Power supply module schematics.