M0110/M0110A to USB keyboard converter

This firmware converts the protocol of Apple Macintosh keyboard M0110, M0110A and M0120 into USB. Target of this project is USB AVR controller ATmega32U4. Using this converter you can revive these retro keyboards with modern computer.

Read README of top directory too.

Pictures of M0110 + M0120 and M0110A.

• M0110A support was contributed by skagon@github.
• M0120 also is supported. keys(+ * / and ,) on M0120 are recognized as cursor keys.

Update

• 2013/08: Change port for signals PF to PD
• 2013/09: Change port again, it uses inversely PD0 for data and PD1 for clock line now.
• 2014/06: Change keymaps

Building Hardware

You need 4P4C cable and ATMega32U4 board like PJRC Teensy. Port of the MCU PD1 is assigned to CLOCK line and PD0 to DATA by default, you can change pin configuration with editing config.h.

4P4C phone handset cable

Note that original cable used with Mac is straight while phone handset cable is crossover.

http://en.wikipedia.org/wiki/Modular_connector#4P4C

Close-up picture of handset cable. You can see one end of plug has reverse color codes against the other. Click to enlarge.

Socket Pinout

• http://pinouts.ru/Inputs/MacKeyboard_pinout.shtml

Pull-up Resistor

You may need pull-up resistors on signal lines(CLOCK, DATA) in particular when you have long or coiled cable. 1k-10k Ohm will be OK for this purpose. In that case the converter may not read signal from keyboard correctly without pull-up resistors.

Building Firmware

To compile firmware you need AVR GCC. You can edit Makefile and config.h to change compile options and pin configuration.

$ git clone git://github.com/tmk/tmk_keyboard.git (or download source)
$ cd m0110_usb
$ make clean
$ make

To select keymap use KEYMAP option.

$ make clean
$ make KEYMAP={plain|spacefn|hasu}

Keymap

To create your own keymap copy existent keymap file to keymap_name.c and edit it. You can build it like this.

$ make clean
$ make KEYMAP=name

Debug

You can use PJRC HID listen to see debug output. The converter has some functions for debug, press <Command>+H simultaneously to get help.

• Command: Shift+Option+Command(Shift+Alt+Gui or Shift+Alt+Control)