Hello,
My brother brought a Model M home this morning. Presumably, its model is 1391412 (Largest numbers on the backside. I assume this is the model number). It's dated 1st April, 1992, made in the UK. Logo is gray, top left corner. The F9 and "Numpad -" key caps are missing, but there's a gray stub that they were mounted on, that is still present. Both keys are operational. It also comes with a detachable cable.
Weirdness starts here. The PS/2 end of the cable only has 4 pins. Upon closer inspection, there seem to be traces of the missing pins where they used to be (Pins #1 and #3 clockwise from 12 o'clock). However, the traces are very faint and are covered with black plastic. My brother insist that there were only 4 pins initially. I'm not so sure about that. Keyboard works, however. I don't know what to make of it, is that a normal occurence?
The keys feel very weird as well. Admittedly, I've never used a mechanical keyboard, but the thing is that the backforce from the keys makes them not trigger properly sometimes. Maybe I'm not pressing hard enough, who knows? I can also hear the springs inside when I press the keys properly and they produce this mildly annoying sound in addition to the click.
