Old Keyboard Key Switches
not a complete list, but i begin to collect and sort out.
Ancient Switches
Invac PK-200 keyboard. 1966 Invac Optical switch
Univac F-1355-00 Keyboard, 1971 Univac Magnetic Separation Switch
ITW Magnetic Valve Switch 1975
IBM 5251 Keyboard 1977, beam spring switch
Buckling Spring Key Switch 1980s
Hi-Tek 725 Switch (Space Invader Switch) 1983
Cherry MX Switches
1983