Brother ProCal 310 Technology

Electronics

Early Mitsubishi MSI MOS “calculator on three chips”:

Additional logic is provided with Mitsubishi M58— family chips. Transistors buffer between logic levels and the display tubes.

Display by 10 7-segment vacuum fluorescent tubes.

10 displayed digits

One main PCB with 3 ICs as above and one support IC. Low volt power supply and high volt display supply on same board.

Keyboard has reed switches with moving magnets on the key stems.

There is comprehensive interconnection of all major internal metal parts for grounding and MOS static protection.