11/45 progress

From: Eric Smith <eric_at_brouhaha.com>
Date: Sun Feb 13 23:51:59 2005

Jay wrote about the PDP-11/45:
> Speaking of which, how can one test the voltages without an extender card?
> Maybe hunt down the right pins on the backside of the backplane?

Yes, that's how I've always done it.

> Then I've got a question about termination, but I'm still going through
> some documentation to see if I can figure that out myself.

The 11/45 contains two Unibuses, but they are normally connected
together with an M920 bus jumper, which goes between slots 26AB and
27AB. Slot 28AB would either have a Unibus cable or jumper to
another backplane or box, or a terminator.

The normal terminators are the M930 or M9302, though it's common to
use an M9301 or M9312 bootstrap/terminator module instead.

If Unibus B is used separately from Unibus A, it needs to be
terminated with a special terminator, the M9300. I can't find
detailed info on that.

Eric
Received on Sun Feb 13 2005 - 23:51:59 GMT