Keyboard Layout

Here is the current state of my new parallel ASCII keyboard layout. It is setup to use Cherry key switches and the encoder is a 40 pin AVR micro controller. I plan on making the encoder/controller key mapping configurable through the keyboard itself. It should work nicely as an Apple II/IIplus replacement keyboard, an Apple 1 keyboard, or a more generic ASCII parallel keyboard. The strobe will be configurable as a pulse with configurable duration, requiring an ack, or simply follows state of keypresses. The later mode will only keep strobe active and data output valid while a key is pressed. Like Wendell Sander’s design, the power light doubles as a caps lock key. Note that I plan on making the power/caps lock light configurable to indicate general power/health or caps lock status.

Due to making configuration through keypresses, most of the solder jumper locations will go away, but I might need to leave the reset option in the layout. I still have a lot of work to do around the micro-controller section plus a lot of design verification. I also intend to retro-ize the traces to make them look more like a hand laid layout that could have been done back in the 70’s.

In keeping with the original Datanetics rev D., upon which this is based, I may leave out the silk screen layer on the final PCB.