Symbolics 364000 Rev. C

Symbolics 364000 is a model of keyboard designed for the 3600 family of Lisp machines. These keyboards were made by Micro Switch. 364000 revision D (…) has been found with Micro Switch SD Series Hall effect switches (4B3E). Revision C, pictured on the aforementioned page and shown in more detail below (serial number 1137), uses the original pre-DIN Micro Switch SC Series capacitive membrane system, specifically catalogue listing 88SC22-2 manufactured in week 6 1984.

Photos courtesy of Keymacs.