Josh I posted photo of a manual we had a long time but not too long
if you want to search the cctalk here.. Also always wondered which
plant built in... is this same basically as a pbp 8 or is it just
that they are both 12 bits? Thanks Ed# In a message dated 9/29/2020
11:26:36 PM US Mountain Standard Time, cctalk@classiccmp.org writes:
Hi all -- This is a long shot, but I was curious if anyone might have
information onthe Motorola MDP-1000 minicomputer. I picked one up recently and
I'mworking on restoring it. Of particular interest is the power supply,
whichis external to the processor and which I am missing. I think I have
thevoltages worked out (+/-5V and +/-15V), but there are a number of
othersignals on the power supply connector that I'm unsure of at the moment.
I've put a few pictures up here:
https://1drv.ms/u/s!Aqb36sqnCIfMpIVYmzKjFnsT3nHh8w?e=b2iqqv I'll note that this
isn't technically an MDP-1000 -- it's labeled as anMDP-6650 on the rear. I
suspect that this is a ruggedized version of the1000 intended for harsher
environments. The front panel of mine appears tobe identical to the drawings
of the MDP-1000 in the manuals I have. It also came with a binder of
documentation (but alas no schematics) thatI'll be scanning soon and getting
off to Al. It's an odd little system --5 12-bit registers, a 12-bit ALU, and a
12-bit Instruction Register, butthe memory is 8 bits wide. Instructions are
packed into two bytesnormally, but there's a special 64-byte region of memory
that can be usedto store "shared bytes," which allow encoding certain
instructions into asingle byte, taking the other byte from the shared region.
I've never seenanything quite like this. I wonder why they didn't just use
12-bit widememory... Also the process for using the front panel to examine and
deposit memory isinsane. Here's the instructions for reading a memory
location; it's 10steps. Depositing is 17.
https://1drv.ms/u/s!Aqb36sqnCIfMpIVWThgwlxgCMQo59A If anyone has anything on
this, let me know. Not expecting much, but it'sworth a shot.- Josh
