Litronix Checkmate

This rare Checkmate was the first portable electronic calculator developed and manufactured by Litronix It is one of the rare designs using the original Klixon keypad without the TMS0100 MOS/LSI calculator-on-a-chip. The printed circuti board (PCB) of the Checkmate is centered around a LIT-019 calculator circuit, discrete display drivers (the two white ceramic housings are current limiting resistors manufactured by Beckman), and thee Litronic display modules with 3 digits each.