You probably mean a DECStation 2100 or 3100. Those are both R2000 based, only difference between 2100 and 3100 is that the 2100 runs at 12 MHZ and the 3100 at 16. NetBSD supports them quite well. Probably the fastest small workstation at the time they came out (1989). They look like, and use the same (or very similar) case, power supply, peripherals, as VS3100/30/38.