SORD KB-100

The photographs below (from UncleFan) depict a Japanese layout SORD KB-100 keyboard, manufactured by Mitsumi. The general design is the same as the better-known M243EX KB keyboard, but there are a few differences. KB-100 appears to have a standard DIN-8 plug, while M243EX KB has a similar plug but with more densely-packed pins. The external serial number is J6301463. Unfortunately there is no internal Mitsumi date label and the PCB does not indicate the Mitsumi series. The switches are Mitsumi’s “standard mechanical” switches, second generation, linear.

The encoder circuitry comprises a Hitachi HD6303RP microcontroller, a Toshiba TC5517APL 2048×8 bit (16 kB) SRAM chip, a Fujitsu MBM2764-25 8192×8 bit (64 kB) 250 ns EPROM and an assortment of logic chips.

This Mitsumi model does not use the stepped keycaps characteristic of Hirose.

From the ICs, this keyboard dates to around 1986.