A number of people have volunteered a lot of information: this is mostly me collecting facts in one place so I'll lose track of less of it.
There's a problem here, and I'm not quite sure how to express it: there's a barrier to entry somewhere between "where do I start?" and "what does this mean?" I have a keyboard. I know I'm probably going to have to decode the keyboard matrix and connect it to a ATmega32u4 (probably on a Teensy 2.0). But the people who write these pages have already done so and understand things, use terms, which I don't get yet. What's the entry point for all of this? The "starting from Zero" tutorial?
- How Key Matrices Work
- How to Make a Keyboard - the Matrix
- rampadc's "A Better ThinkPad USB Keyboard Adapter"
- rampadc's github repo for the code
- rampadc's github repo for Arduino Trackpoint - with instructions ... wait, I need a SEPARATE Arduino Leonard just to read the Trackpoint?!
- 340CSE System Board drawing
- basic info about the 755CSE (this is a more expensive model: the physical appearance is nearly identical, although the screen is larger and the power adapter is different)
- Install Classic Keyboard on xx30 Series ThinkPads - putting a xx20 keyboard on an xx30 ThinkPad. Not sure this is useful, but somewhat related.
- Quantum Mechanical Keyboard Firmware - firmware for a variety of keyboards for Atmel AVR controllers
- long discussion on a similar topic - not yet mined for all its useful information
Finding an Teensy 2.0 in Toronto turns out to be trickier than you'd think: my usual computer suspects (Canada Computers, New Egg) don't have it. Amazon Canada only has it from secondary sellers. Creatron only has the 3.2. Sayal - to my considerable surprise - doesn't seem to have any of them. The Adafruit version listed above would be great, but buying from American sellers can be problematic on this side of the border.