Micro Switch 76SD30-2
Micro Switch 76SD30-2 is a rather unusual specimen of Micro Switch SD Series. The visible switches are 4U3E; most switches are not identifiable from the photos. 4 (momentary), 3 (2.5 oz) and E (three-terminal) are all normal characteristics. However, plunger type “U” corresponds with the non-standard cruciform mount switches. No information is presently available regarding the mount used. It appears that all keycaps except space bar may have been harvested, as it seems was the controller. There is a surprising amount of TTL on the keyboard considering that it seems to use a controller.
The manufacture date is week 13 1985, and the serial number is A0356. The PCB part number appears to be SD-16677 although this is partially obscured by the mounting plate.
The photos below were archived from eBay listing 234035913007 “One Vintage NOS Micro Switch Keyboard & Circuit With IC's” from seller snowman-113; this listing has subsequently been erased from eBay.