20220422 Gould AS 9002 - jsheradin/kb_adventures GitHub Wiki

Weiging in at 11.4 lbs this keyboard features an all aluminum shell that's minimum 5mm thick at all points. It was initially part of an industrial PLC system branded as Modicon. Supposedly that system introduced a now de-facto standard Modbus control protocol.

The keyboard assembly itself is made by Honeywell/Microswitch and bears prototype production markings. I'm not sure if it's actually a prototype board or, what's more likely, Honeywell just used their prototype assembly line to run small batches of high margin boards like this one. The caps are the standard Honeywell/Microswitch variety with very nice colored legends. The switches are Microswitch tall stem SC series. Supposedly the tall stem variety are extremely rare, this being only the second board known to use them.

The switches are a capacitive tactile plate spring design. A spring in the stem pushes on a plate spring which buckles and makes contact with a membrane. This pushes two layers of the membrane together which changes the capacitance between them. The layers of the membrane never make actual electrical contact. They're sharply tactile and and sound quite similar to Alps SKCP switches.

The layout matches that of the Cortron CT-64, a Microswitch SD based board. MMcM has already dug up documentation and designed a QMK based controller in the past. The pinout of the Gould is different however some fiddling showed that the underlying protocol is identical. With some wiring changes, the converter firmware works perfectly and enables full NKRO USB support. I made a simple bulkhead mount for the USB port to try and keep with the industrial build quality.