Apple ][ converted into USB keyboard

Sometimes it’s apparent that there is no practical use for something featured on Hack a Day, but we don’t know if [Andrew Filer]’s Apple ][ USB keyboard qualifies for this.

After reading through the very thorough documentation available in electronic and dead tree formats, [Andrew] decided that Apple ][ would make a great USB keyboard. Unlike modern keyboards, vintage computers like the TRS-80, Commodore 64, and the Apple ][ return the 7-bit ASCII value of the key instead of a scan code. The ASCII codes generated by the keyboard were sent through a Teensyduino running [Andrew]’s keyduino sketch.

Modern PS/2 keyboards use MAKE and BREAK scan codes sent from a microcontroller that reads the keyboard matrix. For example the MAKE code for the letter ‘A’ is 1C, while the BREAK code is F0 1C. There is a reason for this design, but for the DIYer, interfacing a keyboard becomes a challenge without a separate microcontroller. We’re thinking [Andrew]’s keyduino could be a great way to put a keyboard in a project, but we’re not about to tear up our Apples and C64s to get a keyboard.

13 thoughts on “Apple ][ converted into USB keyboard

  1. Actually, most vintage computer keyboards are scanned matrix. The TRS-80, Commodore 64, Atari, Timex Sinclair, and a few others spring to mind as scanned matrix.

  2. why not write the code to interface to the USB bus directly in 6502 assembly, have the ][ read its own keymatrix, and present it to the USB bus? Bet it could be put on a card w/the requisite code in EPROM, then you could PR#5 (or something) to run the thing as your PC keyboard, no permanent damage to the ][.

  3. As David pointed out, many vintage pc keyboards were ‘dumb’ scanned keyswitch matrixes.

    The Apple was somewhat unique in this respect as it’s kit based heritage provided the ability to provide your own ascii based keyboard, which was common at the time for terminals.

  4. I didn’t modify the Apple ][ for this, I just pulled the keyboard cable out of the motherboard and stuck it into a socket. And this particular machine was already dead, so nobody should worry that I killed a viable ][.

  5. (Actually, this could be very useful to me… I’m thinking of wiring up an adapter to a Raspberry Pi and making an Apple pi (bad joke cymbals). For those who *don’t* know, the Apple IIe has a screwless case and this is a non-destructive mod.

    1. I’m working on a dual android apple 2e mod. Thinking about wiring it into one of the card slots for power and some basic control powered by the 2e. Not sure how I’m doing the video yet, but thanks to this I got the keyboard down. Thanks btw :) I’ll drop a link on hackaday when I got ur all done.

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