KIM-1 replica keyboard – Retro Computing

Construction of a nearly exact KIM-1 replica keyboard.

Original version: Design, images and original text in German by Ralf (ralf02, forum64.de), from the KIM-1 Aufbau anleitung, and KIM-1 Keypad by user hackup, October 30, 2022 on thingiverse

Circuit diagram of the Keyboard PCB

For the keyboard construction you need the following parts:

1 3D printed keyboard frame, STL from thingiverse
2 keypads with 16 keys each as shown (actually, you just need 1 1/2)
1 keypad PCB, see the gerber file
1 SPDT slide switch, 2.54mm pitch
1 female pinheader connector, 15 pins, preferably low profile
1 male pinheader, 15 pins to match the female one
6 self tapping screws, 2x6mm
labels printed white on black for the keys E, F, AD, DA, PC, +, GO, ST, RS
double sided adhesive tape to glue the clips to the motherboard

The keyboard PCB has to be gold plated (ENIG). With tin-plated PCBs the contact from the keys is not reliable.

Downloads made available by Ralf:

First dismantle the two keyboards and cut the two rubber contact mats as seen in the next picture. Keys 0-0 and A-D have the right lettering, make the other with a letter printer white on black.

Place the keycaps in the 3D printed case:

Now solder the slide switch and the pinheader on the PCB. Cut the rubber mat on the location of the slide swithc. Put the mat in the 3d printed case and fix with 6 screws:

Next place the four M3 screws in the holes in the PCB and the parts in the case. Now place the PCB on the 1 pin pinheader and fix the four screws with washers from the bottom.