Make That C64 Keyboard Work As A USB Keyboard


Let’s face it, we all have keyboard peculiarities. Don’t try to deny it, everyone who types a lot has an opinion of the keyboard they stroke so frequently. We know [Brian Benchoff] swears by his model M, and we’re guessing he was the one that bumped into [Evan] and convinced him to write about his conversion of a Commodore 64 keyboard for use as a USB device.

This is not [Evan’s] first rodeo. We recently saw him fixing up the worn off letters of his own model M. But this time around there’s some clever microcontroller work at play. Apparently mapping 122 keys using an Atmel AVR 32u4 chip (built in USB connectivity) is quite a task. Luckily someone’s already worked out all kinds of good things and is sharing the love with the Soarer’s Keyboard Controller Firmware. Of course it handles scanning, but also includes¬†debounce, muxing, and the trick to scan more keys than the uC has pins for. We still don’t fully understand that bit of it. But [Evan] did post the config file he’s using so perhaps after we get elbow-deep in the code we’ll have a better understanding.

If you give this a try, we want to hear about it. Anyone have any modern keyboards they’re in love with? Leave a comment below.

25 thoughts on “Make That C64 Keyboard Work As A USB Keyboard

  1. I greatly preferred the C128 (or the late model thin C64) keyboards over the C64. Although I had literally a BOX full of C64s at one point (on the order of 10 – 12).
    That later translated to an absolute love of the Amiga keyboard. I have yet to find another that compares.
    Not sure why so many people love the retro clicky boards. Being built like a brick is one thing.. That I can totally respect. But I prefer softer, silent keys.

  2. Keyboards are keyboards – type on whats put in front of you. Humans are marvelously adaptive (the main argument for manned space exploration) so this whole keyboard fetish always puzzles me. Assuming the keys work, I can type 80ish words per minute on whatever there is – does a certain keyboard make people type faster or is it just some sentimental nonsense going on up in the pointy grey matter region?

    1. I’m not arguing that you can’t do it. But I think it’s hard to say you don’t notice a difference and have no opinion. For instance, I have a C710 and a C720 Chromebook. The 720 blows the 710 out of the water… except for the keyboard on the 710 which is both nicer to type on (the keys seem to be more “attached”) and there are physically more keys. Functioning without home, end, pgup, and pgdn gets annoying after a time.

      1. My C710 with SeaBIOS’d Coreboot and Debian is by far my favorite of all the laptops I’ve had. Not to mention the cheapest. Acer, for all their faults, knows how to make a good laptop keyboard.

        I’m disappointed that the C720 went to soldered down RAM though.

    2. An unlikely claim. Key stroke length and resistance has a LOT to do with your typing speed… or at least, for how LONG you can maintain 80 wpm. I have no doubt that on nearly any, what we would reasonably consider a keyboard (as in excluding membrane keys, etc) that you could do 80WPM anywhere. But for how long? Fatigue is a very real concern for keyboard designers. In case you have not noticed, keyboards have become a LOT easier to type on since the 70s.

      I have a netbook with a tiny spaced keyboard and keys that offer up a lot of resistance and stick (they are clean.. its just a crappy keyboard). No way I can do anything close to my normal wpm on it. after a few minutes my fingertips hurt, my wrists are all turned out and I am tapping keys two or three times to get it do depress enough to register.

      your claim is a lot like saying “I don’t get car fetishists. What’s the difference between a Ford Escort and a Ferrari?! they both have seats, wheels and an engine. They both drive. I can go equally fast in any car. Drive whichever car is in front of you.”
      Every single statement in that is false.

      1. By the way, the early electronic keyboard designers had to ADD in those stiff resistance key springs and clicky bit because they typical typist at the time was literally tearing keyboards apart. They were used to typing on mechanical typewriters which required a lot of finger strength to depress keys. Designers tried soft keyboards and they fell apart in the hands of trained typists.
        Most of the world is less than 40 years old, and either just barely remembers those old typewriters and clacky keyboards or don’t remember at all. We no longer have the digit strength to hit 80wpm on a manual typewriter. keyboards get softer over time.

    3. Keyboards _aren’t_ keyboards. I can type all day on any that have dished keycaps, but the minute I go near laptops with flat plate keys I can’t type for long. Thankfully I can plug in a USB keyboard into those devices.
      This comment is being typed on a DEC RT101 keyboard made in 1993 or so, that I completely disassembled earlier this year to wash all the caps, posts, guides, springs etc. With any luck it may go for another 20 years.

    4. You are kidding right?
      Sure, I can type on whatever is in-front of me… But while I can comfortably touch-type on my ergodox, I’m reduced to 4-finger typing on a conventional keyboard because trying to touch-type on one hurts me!
      People should try lots and use what is comfortable… And the typewriter-qwerty stagger should be consigned to the dustbin of history…
      Now to design an extended ergodox with F keys… Lots of F keys…

  3. I have a non working Commodore PET that I’d love to modernize. I may use what is covered here and make PET keyboard work with USB. Throw in a Pi and PET based emulator, and replace the screen with 9′ VGA panel.

    1. If you replace the tube screen with a flat, you could keep all the original gear, having a REAL PET still in operation, but stuff a modern system into the monitor box. Flip a switch and boot the PC. Flip it back to play with the PET. Multitasking ;0

      1. Pretty hard to repair when one piece needed to make it functional is about as rare as hen’s teeth. I need a 6702 chip which was only produced by MOS in early 80s and the internal design is still a mystery so no one has been able to produce a working replacement clone. Until compatible chip comes up without needing to rip apart an already hard to find PET model 9000, it’s just easier to take the gut out and sell it for parts and turn the case and keyboard into modern PC powered by a Pi.

    2. If it’s the PET 2001 model, with the 9″ screen (and I think the wierdo early keys) then they’re worth a LOT of money! The later ones, would probably cost more in petrol to take to a scrap yard than you’d get from selling the metal. Although we wouldn’t do that. I had a PET setup with dual full-height drives and all sorts of bits ‘n’ pieces. In the late 1990s. LOVE the bonnet-prop for opening the thing!

  4. So in short he just reads out the keys and use some sort of USB HID library to generate USB Keyboard / Mouse events. Okay nice but on the other hand i do not see it finally mounted or anything else.

    And there is sure documentation of how to read out the letters as this is a common hardware available. I am not sure about the coding but i assume maybe less than 2 pages of code. If done efficently.

    It is just a proof of concept to me which works on anything. He could have used anything as input device as he used an USB Chip with the appropriate libaries.

    Okay cool when he likes to have this device for himself.

  5. Keyboard preference is quite real. I started using a Microsoft Natural Keyboard in the mid-90’s and replaced that with a Microsoft Natural Multimedia Keyboard which has nearly the same key layout. I have found no other keyboards that work as well for me. I’m still kicking myself for A: getting rid of my first MS-Natural keyboard, a B: not stocking up on the MS-Natural Multimedia keyboards back when they were cheap and plentiful.
    The current MS-4000 keyboard is junk by comparison (sadly, I have 2 of them).

  6. I use an IBM POS keyboard that is normally used for cash register systems. It has a wonderful sound, excellent tactile sensation and because it is designed for a punishing retail environment, it will last forever.

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