[M]ouse: a PS/2 to c64 adapter

4100951630_8cb9dc6164 (Custom)

[svofski] has a friend who is a pixel artist. They really wanted to try out their skills on a c64, but were missing a mouse. The original mouse for the c64 was not only serial, but used a different method of communication than more modern mice. [svofski] built this adapter to translate the ps/2 data to something the c64 can use. The writeup describes the build in detail and even has the PCB and source code available for download.


[via flickr]


  1. Frank McSteez says:

    What a ridiculous looking mouse.

  2. strider_mt2k says:

    Nice work!
    This is something I can see more than a few retro-rig runners…uh…running.


  3. Karateboy says:

    If your going to go to the trouble of doing this then why not just make it for a usb mouse instead of PS2? I mean seriously it’s getting harder and harder to find a PS2 mouse every day so why replace one mouse that virtually can’t be found with one that will be the same way very soon?

  4. sarsface says:

    @karateboy Probably because translating ps/2 data to serial is much simpler.

  5. Dan K says:

    PS/2 Data IS serial. The adapters for the PC for ps2->serial port are simple pin to pin connections.

  6. rasz says:

    pluz there are still USB mouses that also work with PS2 adapters

    and USB mouse needs USB host, and USB host needs a lot of hardware/software compared to serial. There was one bitbanged project using mega32, other option is AVR with host build in ($6). Both are faster than C64 .. kinda pointless

  7. cow_juice says:

    @karateboy ps/2 and usb are just different connectors, you could wire this either way by only changing the connector. see: http://pinouts.ru/InputCables/usb_ps2_mouse_pinout.shtml

    @dan k this is not a simple serial interface, but a special one for a 1351 mouse. not sure if you were confused on that or responding to someone else.

    now this is a /hack/, not an audrino mod.

  8. the_woz says:

    Oh hell yeah!
    I’ve been waiting for a PS/2->1351 adaptor for years.

    There was a serial->1351 adaptor before, but finding serial mice nowadays is almost impossible.

    The 1351 mouse (which this adaptor emulates), “send” the X and Y axis movement through the C64 analog paddle inputs.

  9. sly says:

    It’s essentially a joystick port more than a serial port. The old Tandys were the same idea with round ports. The mouse essentially had two pots that moved to the extremes of the screen. You could plug in a joystick and do the same things the mouse did without and driver changes.

  10. svofski says:

    I did a PS/2 adapter because a PS/2 host is infinitely more simple than a USB host. A dual-standard mouse with a USB-PS2 adapter would work too, although I never tried. People who are not afraid of using a real Commodore 64 in 2009 tend not to experience shortage of real PS/2 mice.

    C64 mouse taps into analog paddle lines. It’s very simple really and it’s easier to show on a scope than to explain it verbally.

  11. James says:

    cow_juice, PS/2 is not USB, for that adapter, the mouse has to be designed for the adapter. It’s the same story with trying to get a PS/2 keyboard to work.

    Look up PS/2 on wikipedia, and they will tell you that it is a serial interface.

  12. doc says:

    Load “*” , 8 , 1

  13. Seth says:

    “People who are not afraid of using a real Commodore 64 in 2009 tend not to experience shortage of real PS/2 mice.”

    So true, so true.

  14. therian says:

    really good hack, but what the hell wrong with this mouse ? it looks so ridiculous

  15. David Murray says:

    Actually, PS/2 is serial, but it is NOT standard RS-232. In any case, the C64 uses an analog mouse. I actually designed a mouse driver that will run a PS/2 mouse off of the user-port of a C64 DTV. Look here: http://galaxy22.dyndns.org/dtv/common/ps2mouse/index.html

  16. jim says:

    Am I the only person that would like to use a C64 as a PS/2 keyboard for a PC?

  17. jake says:

    This isn’t the sort of hack that really interests me, but the documentation and write up is so perfect, and the actual hack is so neat. Inspiring.

  18. Graham Simpson says:

    I should totally do this for my A1200, now that I have an oscilloscope! I could also hook in my Cyborg digital as a joystick…

  19. Wwhat says:

    Don’t quite get the interest people have in the c64, and if I had one working and in use what I’d mod first is the lousy shielding, how that thing ever got through the FCC I’ll never know.
    Its shielding was a piece of thin cardboard with aluminum foil stuck to it, for those that don’t know. and if that wasn’t bad enough it just folded along the length over the top but left 3 sides open.

  20. tnt23 says:

    @Graham Simpson
    Amigas don’t support paddles or joysticks with analog outputs AFAIK. Shouldn’t be hard to tweak the design for Amigas I guess.

    Cool hack anyway.

  21. svofski says:

    @Wwhat: don’t quite get the interest people have in the FCC.

  22. cantido says:

    >PS/2 is serial, but it is NOT standard RS-232.

    RS232 != “Serial”. RS232 is a “type of serial communications protocol”. SATA is serial, doesn’t mean you can plug a “serial mouse” into it does it?
    Even if PS/2 was RS232 compatible, RS232 only defines low level stuff like signalling levels, data representation, so two “RS232 mice” for different platforms could use totally different protocols on top of RS232, so you would still need some sort of translation.

    >Graham Simpson

    There have been PS/2 -> Amiga mouse adaptors for yonks. I think there have been schematics up on Aminet for the best part of a decade. Individual Computers have also produced all sorts of similar stuff over the years,..

  23. svofski says:

    I made a video that shows what exactly is happening on POTX/POTY lines of C64’s control port when a 1351 mouse moves:

  24. pookeye says:

    Actually, it really isn’t so much of an issue of who’s interested in the FCC as it is whether or not the FCC is interested in YOU.

    @svofski said: don’t quite get the interest people have in the FCC.

  25. tehgringe says:

    @McSteez & therian

    The mouse may look a bit goofy with the cable pointing vertically but I work on a small desk with plenty of desk fodder around, and one of the most annoying things is the bend in the mouse cable when it pushed up against something.

    I would like to have one of these mices :)

  26. Wwhat says:

    Lol, it’s not the FCC that I care about but rather the radio interference that gets into my stuff.
    It just seems so incredible it was approved.
    No ‘white space’ within 30 yard of an c64 I can tell you.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 96,345 other followers