This repository contains a project to create a modern replacement PCB for Apple Lisa keyboards.

The Apple Lisa used a Keytronic foam and foil keyboard which is notorious for the foam turning to dust rendering the keyboard unusable. Even after replacing the foam, I was unable to get my Lisa keyboard fully working, so instead I created a replacement PCB so I could use modern keyswitches.

This repository is still a work in progress. The timing on the keyboard controller code still needs adjusting, and the PCB may require further revisions. For example, I only recently added stabilizers to the board. If you downloaded the PCB designs before 28 November 2023, you will want to download them again to get stabilizers and a better fitting PCB. Otherwise your keys won't be stable and you'll need to expand some of the holes with a Dremel.

• 76x Cherry MX compatible keyswitches
• 76x through-hole 1N4148 diodes
• 1x through-hole 3mm LED
• 1x through-hole 150 ohm resistor
• 2x through-hole 3-pin 2.54mm-spacing male headers
• 2x through-hole 14-pin 2.54mm-spacing male headers
• 1x through-hole 5-pin 2.54mm-spacing male header
• 1x Adafruit ItsyBitsy 32u4 5V microcontroller
• 1x 2-pin jumper
• 6x 2u stabilizers
• 1x 6.5u stabilizer (good luck; you will most likely need to get a 7u stabilizer and shorten it)

• 1x keyboard matrix PCB, made from the Gerber files in the gerber directory
• 4x mounting brackets, 3D printed from the STL file in the mounting-bracket directory
• a set of keycaps, made from the templates in the keycaps directory (more details needed)
  • The hardest to get will be the 6.5u spacebar and the 1.5u backspace. Max Keyboards will make custom sets with a 6.5u spacebar. I haven't found a source for 1.5u backspace yet. You can use a 1.5u backslash key, but the profile will be wrong.
  • You will need a 1u backslash key.
  • The 1.75u return key can be made from a 1.75u caps lock key.
  • You will need two 2.25u shift keys instead of a 2.25u shift key and a 2.75u shift key.
  • For the bottom row, in addition to the 6.5u spacebar, you will need two 1u option keys, a 2u command key, and a 2u enter key. (The original keyboard had 1.5u command and enter keys and a 7.5u spacebar, but I shortened the spacebar to at least something obtainable.)
  • Instead of num lock, /, *, -, and 2u tall +, the Lisa has clear, -, +, *, /, and comma, all 1u. Additionally, the +, *, /, and comma keys have a unique style of directional arrows on the bottom half of the key.

• Program the ItsyBitsy microcontroller with the Arduino sketch in the lisakeysplus directory
• Solder in the diodes first
• Solder in the LED in the desired location near the caps lock key
• Solder in the resistor and headers
• Solder in the ItsyBitsy microcontroller
• Solder in the keyswitches last
• Add the jumper between VCC and TIP on the header above the microcontroller
• Attach the stabilizers
• Install the keycaps
• Install the four mounting brackets in the bottom of the keyboard case
• Attach the keyboard cable to the header on the top left of the board
• Assemble the keyboard case