This is an industrial keyboard from around 1983 manufactured by Honeywell. It features an extremely rare tall stem variant of the Microswitch SC series switches. They’re clicky tactile and utilize a capacitive sense system similar to the IBM Beamspring or Model F. The tactility is achieved with a spring over buckling plate setup similar to Alps SKCP.

Everything about the board is brutally industrial. Caps are thick, case is thick, cable is thick, etc. It should easily survive a nuclear winter without missing a keystroke.

I’m only aware of one other of these in existence. It seems to be in a museum and displayed alongside its original system (which I sadly don’t have). https://all-andorra.com/modicon-584-hmi/

Fortunately this board shares some similarities with other Honeywell boards made around this time. Although none of them use tall stem SC switches, they shared a protocol so a QMK port from MMcM worked with barely any modification.

The board

Keycap removed

Connector

Case is 5-10mm thick cast aluminum

“Engineering Keyboard Prototype”

Controller

Dirty switches

Tall stem SC

Monstrous caps

Backing and capacitive membrane removed

Buckling plate (think hair barette)

USB bulkhead I printed

Nice and sturdy

Simple converter

Anemic port in comparison to the original

Cleaned and good to go!

The conversion to USB/QMK is reversible should I ever come across an OG system.