You use Windows, yes?
With the funny M...boot up with it connected, then hot unplug it and hot plug it in again. See what happens. Either that or just try to enter your BIOS setup on boot with it (this may not work since key maps may be weird).
I'm thinking it'll start working. Same as all the terminal Ms of that style. SOL for definite info though, that part number is a dead end for google results.
Note: "boot up" means from power off...can't reboot, have to power off/power on.
Show Image(http://www.hexellent.com/files/14/teco-knapp.jpg)
Is that the Teco?