More on building PDP-11s

From: Eric Smith <eric_at_brouhaha.com>
Date: Wed Dec 17 20:21:36 2003

I wrote:
>> Since all of the PDP-11 systems with "real" front panels used Unibus,
>> you can generally use almost any Unibus or SPC peripherals on any of
>> the CPUs. Memory is a little bit trickier; the high-end CPUs like the
>> 11/45 and 11/70 require special memory.

Tony wrote:
> Not so in the case of the 11/45. You can use normal Unibus memory cards
> on that machine, although you need to put them in an MUD slot in an
> expansion backplane, not in the memory slots on the CPU backplane. You
> can also use the core-based system units.

Yes, well, it's also possible to use Unibus memory on an 11/70, but
you have to set jumpers on one of the CPU cards. The Unibus memory will
not be cached, nor will the RH70 Massbus adapters be able to access
it.
Received on Wed Dec 17 2003 - 20:21:36 GMT