deskthority

To my knowledge, 1390131 means square logo and AT cable.

Now, since SDL cables are trivially swappable, the cable doesn't mean much.

However, the 1390131 I have here features a PS/2 cable, an oval logo, and a strange Xeroxed-look label.

See album. at http://imgur.com/a/wcuGz

The board looks like a 1391401 in all but label.

Now, I could see a few possibilities:

* Actual rare product-- oval logo 1391031.
* Hybrid - start with 1390131, replace top cover (or conversely, replace bottom on 1391401)
* Weird fraud or warranty thing (explains sticker?)

Now, I'm not too irate yet... it's still a buckling spring board and I paid an okay price for it, but I wouldn't have bought it if it wasn't a 1390131.

Where did you buy it? "prepared_mind"? "monedas"?

Looks like a frankensteined board to me. Model M parts are easily swappable between models, e.g. my SSK has the controller of a standard Model M.

Further notes...

Componentry with date codes are late 1987; one sticker says "01/88". Key assembly (wire stabilizers on + and enter only) seems similar to an '87 1391401 I already had.