Rejoice the Keyboard Has Arrived

A project log for MCM/70 Reproduction

I am making a full sized MCM/70 reproduction, a Canadian personal computer from 1974.

michael-gardiMichael Gardi 10/28/2022 at 22:320 Comments

I've kind of been in a holding pattern waiting for the keyboard "kit" to arrive but no more as it was delivered this week. This is a classic retro-style ASCII keyboard, modeled after the ADM-3A keyboard, which can also be populated to fit perfectly in an Apple II/II+, or an Ohio Scientific Inc. computer, or as it turns out an MCM/70. For details check out the Unified Retro Keyboard project.

I was able to purchase the keyboard PCB,  a set of Futaba MD-4PCS keys, a stabilizer panel for the Futaba keys, and a keyboard encoder card from Dave from

The first thing I did was to set the keyboard PCB with a few keys loosely set in place onto the partially finished MCM/70 case to get a rough feel for what it would take to integrate the keyboard.

I was happy to see that while it looks like a tight fit, I am sure that I can make it work.  So with some confidence I went ahead and assembled the encoder and keyboard.  I'm not going to detail the process here since it was mostly identical to the work I did on my Sol-20 Reproduction. For details check out:

Here they are.

By design the encoder can be mounted onto the back of the keyboard via the 40-pin headers. This is what it looked like for the Sol-20.

However there is not enough room in the MCM/70 case, so I am going to use the ribbon cable pictured above.

Next testing.