The Sharp Compet 30 was an early electronic calculator, using Nixie tubes to display the value. The electronic design uses discrete Transistors and Diodes. There are two versions of the Compet 30; Version A (This one) uses discrete Transistors and Diodes (650 Transistors and 1600 Diodes) and cannot display negative numbers. Version B uses Integrated Circuits to form part of the logic circuits and the ability to display negative numbers has been sorted.
Both version A and B are otherwise identical in their outside appearance. With Version A, a calculation that would otherwise result in the number -4 would in fact display 99999999999996 on its 14-digit display.
It should also be noted that the warning label on the back of the calculator stipulated not to clean the calculator with Benzene.
|Make & Model||Sharp Compet 30A|
|RAM & ROM||1 Memory register|