Genovation Parallel Micropad 621
I bought several of these on eBay. I got 3 of the Parallel 621 keypads and 1 of the Serial 623. They were a deal for $6 each. They are very old, the drivers available for them are for DOS and Windows 3.1.
It is a modular design and the controller board is easily removed. The matrix has an easy to access pin header. The matrix has diodes for full anti-ghosting.
They are in pretty good condition considering their age.
The switches are some generic clicky ALPS. The keycaps are doubleshot ABS.
The shell is held together with 4 screws hidden under the adhesive rubber feet.
The PCB assembly is held in place by another 4 screws.
The controller board is held on with double stick tape.
The 9 pin header is the 4 column x 5 row matrix connector.
From top to bottom the pins are:
- Col 4
- Col 3
- Col 2
- Col 1
- Row 5
- Row 4
- Row 3
- Row 2
- Row 1
The diodes are oriented Row to Col.
I connected it to a Pro Micro with pre-made jumper wires.
- D2
- D1
- D0
- D4
- C6
- D7
- E6
- B4
- B5
I taped the connectors together to keep them in order.
I soldered pin headers to Pro Micro. It is held down with 3M VHD heavy duty double stick foam tape.
The matrix is so simple I used kbfirmware.com to create the firmware hex. The JSON file I used is
here.
