"IBM Internal Use Only" Model M

[rua0]

So I picked up a Model M on Ebay. Didn't ask the seller to check the part number because it was a square badge, Queen's English board with "tested and working" in writing. Good enough for me. It arrived a few days ago and the markings on the back are quite odd.

First there's a sticker that says "IBM Internal Use Only". Then there's two stickers, both dated to 3/12/85, with two different part numbers. The first is 1386714 (I think, there's a scratch over the second digit). There's no record of this number on Wikipedia's list of Model Ms or the Deskthority list. The second one says 1390136. This ones on the Wikipedia list (although they haven't found a 1985 one before) and the Deskthority list.

Has anyone encountered a Model M with markings like these before? I'm a bit confused.

[mattlach]

1985 was the year the Model M was first introduced I believe.

If I had to wager a guess, this was probably some sort of pre-launch internal test sample.

You may have stumbled upon some sort of collector's item there

[E TwentyNine]

Internal prototypes generally don't have production stickers, and keyboard hardware development didn't take place in the UK.

But those are some early dates.   What you'll want to do is open it up and get a picture of the controller board, specifically the chip on it.

[rua0]

I opened it up last night for cleaning and to count any broken rivets. Here's some fresh photos of the PCB.

[E TwentyNine]

Looks like a standard production model, but early.  Nice find.

[JP]

Maybe it's like an asset tag and was used at some IBM location? Sort of like a "Property of..." tag. Another  guess is they had a policy in place to prevent certain equipment being used by consumers or IBM's customers for some reason.

[E TwentyNine]

IBM slapped IUO tags on everything.