Nakajima All AX-240

The photos below depict the keyboard of a Nakajima All AX-240 typewriter. Those ICs whose markings are readable in the photos tentatively appear to date to 1986. The manufacturer of the keyboard assembly is not known. Although the switches bear some resemblance to those of Mitsumi, the keycaps appear not to be Mitsumi, and the matrix PCB has what seems to be the Matsushita logo, although the switches don’t resemble anything that Matsushita are known to have made.

The separate controller daughterboard uses an D7809G, which appears to be part of the NEC μCOM series of microprocessors and microcontrollers, specifically a μCOM-87 variant (an NEC own-design 8-bit microcontroller).

Photos courtesy of Steve Kuterescz, E.T.ZONE.