rarest computers. was: RE: Xerox Alto Restoration + Emulation

You missed out the NEC 7220 graphics chip which is halfway to being a processor IMHO. So it's a 2.5 processor machine. I have one, still working... I also have, but have done nothing with it yet, a Whitechapel Hitec 20 and a lot of spare boards (not all from the same source). The mainboard is PC/AT formfactor (in fact it's in a PC tower case), and has 3 ISA slots. The other 5 connectors are DIN41612s, for the CPU board (MIPS R2000 CPU + FPU + MMU chips), RAM and video cards. The mainboard contains things like serial ports (although there are 2 more on the CPU board), SCSI, ST506 and floppy controllers, keyboard controller (an 8042, presumably PC/AT like), and so on. Does anyone have pinouts (or other hardware info) for the R2000 chips (I can get the exact numbers if anyone thinks they can help). All I can seem to find is programming manuals. I am supreised that London University didn't have any sort of computer before the late 1960s (that's when TTL came out IIRC). -tony