Arduino-based PS2 -> Macintosh Plus keyboard adapter

This sketch allows to use a PS/2 keyboard with the Macintosh Plus. Mapping between PS/2 keys and Mac keys is stored in the keymap.ino file. Sketch uses a modified version of the PS2Keyboard Library --- all the logic except getScanCode() method have been stripped.

Connecting to Macintosh Plus

Get a phone cord with RJ10 plug and connect pin as follows (pin 1 of the phone jack is on the left when the wire side is facing toward you):

1. GND -> GND.
2. +CLK -> pin D6,
3. +DATA -> pin D5,
4. Vcc -> Vin

Note

Mac Pin 4 (Vcc) can be connected directly to the 5V pin on the Arduino, sharing the same power rail as the PS/2 keyboard. This bypasses the Arduino's internal voltage regulator, ensuring the keyboard receives full power. Connecting via the Arduino Vin pin may cause a voltage drop that leaves the keyboard underpowered (see issue #7).

Connecting to PS/2 keyboard

For the Mini-DIN 6 socket, pins should be connected as follows (the diagram presents the female socket):

1. +DATA -> pin D3,
2. (not connected),
3. GND -> GND,
4. Vcc -> +5V,
5. +CLK -> pin D2,
6. (not connected)

References

• Similar project based on stm32f0discovery kit,
• Mac Hardware Info (ftp://ftp.apple.asimov.net/pub/apple_II/documentation/macintosh/Mac%20Hardware%20Info%20-%20Mac%20128K.pdf) - contains the description of the protocol,
• Mac Plus keyboard rawcodes.