I think what I might try is swapping the controller board out of the Boscom and into the IBM.
Okay, when we last left Our Hero, he had rewired an IBM Model M 1390572 with a PS/2 connector from a defunct keyboard and - on testing - succeeded in causing a seemingly-permanent crippling of the keyboard port on his younger daughter's PC (she is now using Rip's 'Bad Daddy' vignette as her desktop).
I have since received an IBM Model M 1394167 from Kishy and I have the following report:
1. I've heard the Model M called a 'battleship' and the 122-key terminal emulation Model M's 'aircraft carriers'. If that's the case, then the 1390572 is a super carrier, since it has a full inch in width and length on the 1394167.
2. The 1394167 is the 'father' of the Boscom 122 BO40B56 that I've been using for a few weeks. The internals on those two are very similar, while the guts of the 1390572 are different. The biggest difference between the Bos and the IBM is that the plastic keywell on the Bos has the 'drainage channels', where the IBM doesn't. Both cases, however, have the 'drainage holes' at the front.
3. I pulled apart the 1394167 and while the controller was completely different, it had the same ribbon inputs and the same six-pin cable connector. Since Kishy had said that the conversion of his keyboard amounted to splicing in a new cable, I decided to swap the controller from the 4167 into the 0572, along with the cable I'd cobbled together. I confirmed that the cable pinouts matched what I had written down for the six-pin connector on the board and put everything together.
The question of course was: where to test it? I didn't want to risk one of the adult's computers (mine, my wife's, my son's) and Trinity's computer was already broken (Bad Daddy!). That left Shelby's computer. I hemmed and hawed for a minute; but reasoning that I could always plug in a USB keyboard (such as that now sported by Trinity's computer), I gave it a try. I plugged it in, booted, launched NotePad and experimentally whacked at a couple alpha keys.
IT FREAKIN' WORKS!
I was able to use all the alphanumeric keys (and without any of the odd repeating that Kishy had). The function and special keys are different, so they'll need investigated and remapped. But, I think we've got a winner!
For the curious, the dimensions of the keyboards in question are:
Model M 101 Key: 19.25 x 8.25 x 1.75
Model M 1394167: 20.75 x 8.5 x 2.25
Model M 1390527: 22 x 9 x 2.25
For the morbidly curious: I'll post the remapping results when I get that done.