It all started with Project Corona, which would eventually become the Doctor Mab Analytical Engine, mark I.
I had an old model Four from the Corona Typewriter Company (something like this), made in the late twenties, early thirties, which I wanted to turn into a keyboard for my computer.

The first thing I did was to take apart an old keyboard to see how they worked, and to extract what components I could, which turned out to be the controller. I mapped the circuits from it to the various keys, and started working on how to reproduce it with the typewriter. I figured I would attach a wire under each key, that would strike an etched circuit board when pressed.

My first attempt at etching
My first attempt at etching

Turned out to be somewhat cumbersome and not very sturdy. I needed something else. And I found the SoftPot linear potentiometer. The 200 mm fits nicely under the typewriter, and gives you a different current read depending on where you press down. Add an Arduino module (the Teensy 2.1), some coding, and voilĂ . Well, it wasn’t that simple. I had to find the best place to put the SoftPot, find out it needed a resistor or two to work properly, and learn Arduino. Also, as anyone familiar with typewriters will have noticed, I also needed to add some keys (ctrl, alt, etc.), including the number 1, since back then the letter l was used instead.

But while I was doing that, something else came my way, a newfangled tiny computer, the Raspberry Pi. That was the perfect addition for project. No longer was it just a keyboard, now it could be a full-fledged computer; huzza!

To be continued…