2017-04-10 10:09:20 -04:00
Arduino/IIc_keyboard USB Mouse Interface files, Bring IIc shield up to date with IIe 2017-04-10 10:09:20 -04:00
PCB Rev4 of keyboard shields 2014-07-31 22:39:52 -04:00
IIc keyboard pinouts.txt Added macro functions 2014-02-02 08:22:48 -05:00
IIc-keyboard-matrix.png updated READMEs, Fritzing files for 16- to 9-pin adapter 2014-01-14 15:48:37 -05:00
Keyboard Shield IIc.pdf Updated documentation 2015-01-11 00:41:22 -05:00 read me and FAQ updates 2014-02-10 15:23:14 -05:00


###What is it?

The RetroConnector Shield is a breakout board for the PJRC Teensy Arduino clone that, along with the RetroConnector firmware, connects to an Apple II keyboard and turns it into a USB keyboard.

###What does it do?

The RetroConnector Shield turns the built-in keyboard of an Apple //c or //e into a standard USB keyboard that is recognized by any modern computer.

###What can I do with it?

Type on your iPad, Mac, PC or Raspberry Pi with a the 30 year old, super clicky keyboard of your youth. Raspberry Pi RetroConnector Demo

###Where do I buy one?

Currently available at

###What do I need?

The full version, currently $45, requires only a working //e or //c keyboard and the computer you intend to plug it into. Even if all you have left of the Apple II is a keyboard and a ribbon cable, youre all set.

The bare board, $18, requires the following parts/skills:

  • Teensy ++ 2.0
  • header pins
  • female headers
  • box header (34-pins for //c, 26-pins for //e)
  • USB mini cable
  • basic soldering

###Can I hack it?

Yes. All the software and hardware are open source. Everything you need is on github.

To update or modify the firmware on the Teensy, you will also need:

Download and install the Arduino IDE software.

Download and install the Teensy Arduino libraries (Teensyduino).

Download the keypad.h library. Put the unzipped Keypad folder in “arduino\libraries\”.

Download the updated Arduino sketch for your RetroConnector (IIe version, IIc version) and open the .INO file with the Arduino IDE. In the Arduino application, select Tools > Board > Teensy++ 2.0 and Tools > USB Type > Keyboard + Mouse + Joystick

Verify and upload the new sketch.

###How does it work?

The board is basically a breakout for the Teensy pins to connect to the proper pins on the Apple II keyboard connector. The rest is software, sending the right signal down the different pins based on keystrokes. The Teensy does all the heavy lifting, and includes the USB HID functionality out of the box.

###What model Apple IIs will these work with?

The //c version works with the Apple //c,and //c plus.

The //e version will work with all versions of the //e, including those with the extended keyboard, which adds a numeric keypad to the standard keyboard of earlier models.

###Will there be more models available?

If there is sufficient demand, a version for Commodore 64 or other vintage computers with built-in keyboards may be developed as well.

###Do lower-case characters function? I cant remember if that was a hardware limitation or something to do w/ BASIC.

Upper and lower case character input works as you would expect from a modern keyboard. As do modifier keys like shift, control, and caps-lock. Since the Apple //e and //c lack alt keys, the RetroConnector firmware maps “closed apple” key to alt. The “open apple” key is the default “GUI” key (command on the Mac, Windows key on PC). These default mappings can be changed by editing the Arduino sketch running on the Teensy board attached to the shield.

###How about Function Keys and other special keys?

The Shift and Control keys are mapped to their modern counterparts. The left Apple key is Command/Windows key, the right is Alt.

To get Function keys (F1-F10) press CAPS-LOCK and the corresponding number key.

###My //c doesnt work does the keyboard (or Teensy for that matter) require its own power source? Regards.

All you need in working order from the //c is the keyboard and its ribbon cable. The RetroConnector and Teensy get power from the computer you hook it to via USB.

###Can the //c keyboards disk use and power LEDs be programmatically controlled via the RetroConnector? Conversely, can the keyboard LEDs be wired directly into the Pis status LED pads with the RetroConnector installed? Thanks for such a geeky-cool product!

To save space on the board, the RetroConnector Shield doesnt make any connections to the //c Disk Activity LED. As for the power indictor, when power is applied, the power indicator LED should light up. Its not an addressable pin on the Teensy, though, so it cant be programmed in the current version. If youre handy with a soldering iron, it would be an easy matter to connect a couple of lines to pin 11 (Disk Activity) and 25 (Power), and cut the current connection to pin 25. If its a popular feature, Ill add those connections in to the next revision.


My original, hand-wired version was for the G4 Apple //c project. I decided to make it available to see what other people would do with it.


Special thanks go to