Mitsumi
History
Mitsumi Electric Co. Ltd. (ミツミ電機株式会社) is a Japanese electronics manufacturer. Mitsumi produced most of Commodore’s keyboards, as well as many of Apple’s keyboards. The logo on older products is the word Mitsumi itself, written in katakana: ミツミ (mi-tsu-mi, /mʲi.tsɯᵝ.mʲi/), which can be misread as “SMS”. Note the syllable breaks: “mi-tsu-mi” not “mit-sumi”.
On the 27th of January 2017, Minebea and Mitsumi merged. Minebea is now known as MinebeaMitsumi Inc., and Mitsumi is now a wholly-owned subsidiary of MinebeaMitsumi.
Research
Switches
- Standard mechanical (KAx, KCx)
- Standard type 2 tactile
- Standard type 2 (anomalous version)
- Rubber dome and buckling rubber sleeve
When the Commodore 64 was introduced in 1982, the alternate action switch on its Mitsumi-made keyboard used a PCB for the stationary switch contact and the external connections. This switch is connected by inserting bare wire through holes in the PCB and soldering. These switches can however be used with PCBs, as seen with the Okuma Howa HC 74300 keypad.
An unknown spring over membrane type was discovered in the Commodore SX-64. The same type was also found in the Cardinal CP600, in this instance lacking the typical Mitsumi manufacturing date label. In both instances, no disassembly has been performed, and even if it were, it is quite likely that the series name would not appear on the membranes. A similar switch with the newer Mitsumi square slot mount was found in an unidentified typewriter that may be a related Mitsumi type.