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geekhack Community => Keyboards => Topic started by: Delstatenthule on Sun, 07 April 2013, 21:45:28

Title: How to convert this keyboard to USB? (IBM Model M2)
Post by: Delstatenthule on Sun, 07 April 2013, 21:45:28

This is a PCB... how to convert?? To get a USB cable and connect the connector, its ok?

Regards! :)

Title: Re: How to convert this keyboard to USB? (IBM Model M2)
Post by: Delstatenthule on Sun, 07 April 2013, 21:46:39

How to convert to USB? to get a USB cable and connect the connector, its ok?

This is a PCB:

(http://buhoz.net/public/images/computers/20111117-model-m-clara/Foto-0018.jpg)

Sorry for double post :(

Title: Re: How to convert this keyboard to USB? (IBM Model M2)
Post by: Findecanor on Sun, 07 April 2013, 22:15:57

You can't just connect a different cable. The signals on the cable will have to be USB signals.
It you could fit the electronics from an active PS/2-to-USB adapter in there, then that would be great, but I am afraid that there is not enough room.

The difficult route would be to replace the controller, maybe with a Teensy. If I remember correctly, the pitch of the traces of the edge connector is 1/10", which is the same as on a regular stripboard (http://en.wikipedia.org/wiki/Stripboard). You could base your firmware on one of the available Teensy-compatible firmwares that you could find on this board, but you would have to modify the code to know the specific matrix of the IBM Model M2.

Anyway.. Would it be worth it? If you use a USB port on the back of your computer, you wouldn't see the ugly (?) PS/2-to-USB adapter anyway.

Title: Re: How to convert this keyboard to USB? (IBM Model M2)
Post by: esoomenona on Sun, 07 April 2013, 22:17:44

http://geekhack.org/index.php?topic=17458.0

Title: Re: How to convert this keyboard to USB? (IBM Model M2)
Post by: Findecanor on Sun, 07 April 2013, 22:22:33

Bah. I just remembered something. You could use the space in the top part of the case in-between the function key row and the numeric row to place an adapter. The space is long but not too wide.
Anyway, a Teensy++ does certainly fit there.

Title: Re: How to convert this keyboard to USB? (IBM Model M2)
Post by: Delstatenthule on Sun, 07 April 2013, 22:32:59

And there is no way to change the firmware of the keyboard PCB? to be compatible with USB?

Regards.

Title: Re: How to convert this keyboard to USB? (IBM Model M2)
Post by: mich on Mon, 08 April 2013, 20:02:40

Considering its age, this microcontroller is likely way too slow to support USB in software and certainly doesn't have hardware USB interface.

If you really don't want to use external adapters, grab one of these adapters (they are very easy to disassemble and their PCBs are tiny), install it inside your M2 and reterminate the cable with USB plug.
(http://www.vpi.us/images/usb-ps2-lc.jpg)

Alternatively you can try to replace the microcontroller with some Atmel micro flashed with Teensy keyboard firmware, but it's going to be much more work.