IBM M2 Terminal kbd help

[Tactile]

I have an IBM Model M2 42H0468 keyboard I'm trying to get running and I'm getting such odd behavior I don't know how to interpret it. I was under the impression after reading this that after a change of cable connector it would behave as a PS/2 keyboard. Well... that's not happening.

I've connected the kbd to a Teensy. The LEDs work perfectly, even using the LED test in Aqua's key test program.

With Soarer's converter V1.12 loaded onto the Teensy & HID listen running, this is the response when plugging the USB cable:

Code: [Select]

Waiting for device:.....
Listening:
rAA wEE rEE wF2 rFA rAB r83

remaining: 0000


Keyboard ID: AB83
Code Set: 2 (extended)
Mode: AT/PS2

wED rFA w02 rFA
The keycodes just don't make any sense, however. Just one example: pressing "k" lights up "\ |" in Switch Hitter. Here's the HID listen result of pressing "k":

Code: [Select]

r5D +31 d31
rF0 r5D -31 u31
In addition there are also quite a few keys which output nothing, not even seen in HID listen. To name a few:

ESC
Space
Numpad Enter

I've also flashed the Teensy with TMK PS/2 to USB converter code and the behavior is exactly the same.

There's a much longer story of what I've tried but I don't see the need unless someone who might be able to help has specific questions.

Does anyone have any ideas on how to make this work?

[Tactile]

UPDATE:

I've opened it in order to clean the contact areas between the controller PCB and the mylar sheet. And even though I'm not seeing any of the typical "bad caps" symptoms I'm going to replace them just because I'm here, anyway.

We'll see...

[invariance]

Keep us posted for sure.

I read the link and it indicated that it should work with a hardware converter and the only issue is if the key legends differ from ansi.
I take it that didn't work at all for you?

[Tactile]

The M2 did work, just not correctly. No key registered properly.

I'm pretty sure I've found the problem. The M2 controller board makes contact with the matrix traces on the mylar sheet through a row of contact pads. The PCB is simply held tightly in place with this row of contact pads resting against a matching row on the mylar sheet. There is no hard wire connection.

The behavior I was seeing just seemed to be related to the matrix being misread. I think one of these contact points wasn't making a proper connection. One row or column just wasn't being seen by the controller so the controller was just misinterpreting most keypresses (incorrect keycode sent) and not seeing or understanding some other keypresses (no keycode sent - a dead key).  The contact pads on the PCB just look... well... odd. Not corroded but slightly "blistered" is the only way I can describe it.

I'll work with it later today and clean, maybe touch up with solder, and do whatever I need to. In order to test my theory I'm going to initially skip the capacitor replacement & just work with those contact points. I can test it without reassembly by just pressing a finger on the mylar sheet.

[fohat.digs]

board makes contact with the matrix traces on the mylar sheet through a row of contact pads

I have gotten a couple of Ms like that, really stupid idea and bad way to save a couple of pennies.