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IBM Model M keyboard on CX16

Posted: Wed May 08, 2024 2:40 pm
by ifilot
Hi community!

A couple of weeks ago I received the dev board. So far extremely satisfied with it. One thing I tried the other day was connecting my IBM Model M keyboard to it, but it does not seem to work on the CX16, while the keyboard is working fine on my old '486.

Are all PS/2 keyboard supported or are there some differences between them? One thing I read was that IBM Model M tends to use more power (higher current) in comparison to modern keyboards. Could that be an issue?

Re: IBM Model M keyboard on CX16

Posted: Wed May 08, 2024 7:38 pm
by Stefan
We have done our best to support all PS/2 keyboards.

In practice there are small differences between keyboard models.

The IBM model M has specific needs during init that we tried to support in SMC 47. At least one user reported it working.

Re: IBM Model M keyboard on CX16

Posted: Wed May 08, 2024 10:50 pm
by Edmond D
I've got a model M made on the 4th of February 1989 in Mexico "Planta SD" which I can test out once I get time to put my X16 together. It's part number 1391401 serial 0000-SD-0208381 for reference/comparison.

For those who aren't aware the keyboard even has its own wikipedia page - https://en.wikipedia.org/wiki/Model_M_keyboard; in contrast Wikipedia has a few references to the X16, but no page of its own yet. ;)

Re: IBM Model M keyboard on CX16

Posted: Thu May 09, 2024 4:58 am
by ifilot
Thanks for the reply! Appreciated.

I am still running SMC 45, which explains a lot. I wanted to update the SMC, but I read on the releases page for the SMC that it is not safe to do so using the update tool, but one could use an external programmer.

I do have an external programmer (TL866 II). Is it a simple manner of putting the ATTiny in my programmer and flashing SMC.BIN to it?

Re: IBM Model M keyboard on CX16

Posted: Thu May 09, 2024 5:40 am
by Stefan
Basically yes, but you need to use the .hex file.

Also, you need to set the correct fuse settings when programming or ensure that the programmer doesn’t update the fuse settings. There’s usually a check box to do the last

Re: IBM Model M keyboard on CX16

Posted: Thu May 09, 2024 7:17 am
by ifilot
Thanks! I managed to flash the v47 firmware on the ATtiny 816A.

Initially, I still managed to overwrite the fuse settings (despite that I was pretty sure I checked a box not to do so), but I was able to set them to the right values

Code: Select all

E:FE, H:D4, L:F1
I can confirm that with SMC 47 the IBM Model M is fully functional! :D Thanks again for the great help!

Re: IBM Model M keyboard on CX16

Posted: Thu May 09, 2024 7:57 am
by Stefan
Great! We now have at least two model M success stories.