11/44 basic newbie help request

Careful: the M9312 is for the CPU end of the bus, and besides the near-end termination, it provides for diagnostic and boot ROMs, so it is *not* a replacement for the M9302, but it's counterpart for the other end of the bus. As such, the M9312 goes into a MUD slot (*modified* UNIBUS device), which has some pin designations differ from a *standard* UNIBUS slot, which is the reason why the regular terminator (M930 or M9302) needs to go into the last (=standard) slot, not anywhere in between. Hence, the M9312 (designed for MUD slots) must NOT go into the last slot for the same reason. Further, there are some (five? W1 through W5?) jumpers on the M9312 that connect pullup resistors to certain bus lines. There are CPUs for which the jumpers need to be in, other CPUs have equivalent resistors on the CPU boards, so the M9312 jumpers must be out for these. I don't have the details at hand, but can look them up if you don't find the manuals elsewhere. Another near-end terminator and ROM board would be the M9301, but this one doesn't have the pullup resistors. If the /44 needs external pullup, you would be bound to use the M9312. ROM chips are NOT interchangeable between the two boards. Guy Sotomayor wrote: ... -- Andreas Freiherr Vishay Semiconductor GmbH, Heilbronn, Germany http://www.vishay.com