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- 495,531 hits
Thanks so lot!
Bought one on ebay for $68, internal batteries don’t work but the adapter and the calculator does,I had forgotten how tiny those LED displays were,Its also intersting that non of the keys are double function, something that was standard even back then.
It would be interesting to know what voltages are on the converter wires Red, Black and Blue and if Black is common or if Red is common. I guess this is a voltage booster as later calculators used 9v batteries? and this and the SR-9190R used 3 x NiCd batteries.? My Sr-9190R is dead and i cannot see any voltage on the blue wire?
Hi Lee – Blue wire is -6v on my calculator. The first-generation chips required a negative rail, I believe.
The converter actually creates a negative voltage that was necessary for some of the original processor chips. On my calculator, Red = VCC Black = Ground and Blue =-6v.
Hopefully this isn’t a duplicate post! The ‘converter’ actually creates a negative voltage that is required for this generation of calculator chips. Red = VCC Black = Ground and Blue = -6V (on my calculator). Hope this helps.