View Full Version : Early IBM Model M Identification

April 8th, 2010, 03:13 PM
I was reading in someone's thread about the XT 286 keyboard, and it made me start thinking that I may have one. I dug out this Model M from my keyboard rack that I had picked up from behind a Goodwill, I was driving by and saw it in the rain, someone had left it there after-hours so I saved it.

Anywho, the keyboard: It's got a silver IBM logo in the top right, no "Personal Computer" or anything, but it does have space for more lettering below the IBM. It otherwise is fairly normal, except one glaring difference - no numlock/capslock/scrolllock lights or indicators of any kind. The area is covered in plastic.

The numbers on the back:

Part No 1390120
S/N No 2158709
Date 27OCT86
Plt No F2 Model M

So it's from late October 1986. On a hunch, I hooked it upto my Zenith Z-140, an XT machine, and it worked. I then took the Zenith's keyboard, just to make sure, and plugged it in via PS/2 adapter to my main PC, and it did not work. This is an auto-sensing XT/AT keyboard - neato.

Is this what was released with the XT-286?

ClickyKeyboards had several of these pass through, so there's nice pics there. The box they had says "IBM Enhanced Personal Computer Keyboard".

Here's one on ClickyKeyboards that is almost the same age and nearly identical to mine:

April 8th, 2010, 04:43 PM
Yeah, it's believed the early LED-less** Model Ms were for XT-286s (or at very least some other late-model XTs).

I almost picked up a 1390120 once but the bidding can go fairly high on ebay. Ultimately it didn't go for too much but I won't spend much on stuff like that...especially Model Ms. The older they are the less life they have left (plastic rivet-based design means with every drop or bump they lose more of their lifespan). At the time I was also watching an M5-2 so that's what I went with.

**: but don't determine this based on photos alone without part numbers. Some IBM dumb terminals used LED-less Model Ms but the controller PCB is designed for use on those terminals. They can be adapted/hacked for use on PS/2 but not right out of the box.

April 8th, 2010, 05:07 PM
Yeah I'm aware of that, as I have terminal boards too. This, as above, has the right model numbers and such.

Didn't really specify, but the thing works just fine and I'm actually using it to type this. :P

March 16th, 2011, 08:18 PM
these keyboards will still work with newer PCs. However, there is some work involved. You have to build your own controler board inside the keyboard. You can find instructions on GeekHack forums for modifying the model M. These old keyboards use up to 100 times the current as newer USB models too, but again, there are adapters and converters that will do the job. I am currently using a model M made in 1987 on my new PC with no adapters. It plugged into the ps2 on my mobo and worked straight up. I also connected my AT keyboard to my computter using an AT to PS2 adapter and it works as well. (I'm using my AT keyboard to type this) These keyboards are not auto sensing. At least I have never heard of them as beinng auto sensing. The circuitry just isn't there. More than likely, the keyboard PS2 driver was already installed on your computer as part of the OS.