PDP11/23 More dumb questions - test-drb@ccmp.vtda.org

27 Mar 2000

The cards are, from one end:
M8192
M7195
M8067
M8045
M8059

There is an RX50 double floppy drive and an RD50 hard drive.
It's difficult to work out what these are cabled to as they all plug into an
interface behind the backplane.

I've also found out that it ran Venix in it's first life. It was connected
to a PDP8/A that I also have but can't do anything with because of it's
state.

I'm unclear about the switches and lights, but I have the run light on, the
DC light on, the fixed disk write protect switch out and it's red light out,
and the fixed disk ready switch out with it's green light on.

There seem to be some (slight) behavioural differences depending on which
serial port I plug the terminal into.

Hans

-----Original Message-----
From: CLASSICCMP(a)trailing-edge.com &lt;CLASSICCMP(a)trailing-edge.com&gt;
To: classiccmp(a)classiccmp.org &lt;classiccmp(a)classiccmp.org&gt;
Date: Tuesday, 28 March 2000 0:49
Subject: RE: PDP11/23 More dumb questions

...
 >Anyway, I start the VT220 before the PDP and it
gives a message VT220 Ready.
...
 >I power up the PDP and basically get nothing at
all. The only sequence that
...
  gets any
response is hitting the halt button. The terminal then says:
165262
@
When I hit the Restart button after that nothing happens for about 2
minutes.
Then an "&" prompt appears.
Nothing I type in gets any response after that. Typing "help" gets no
response. 
The "165262 @" prompting is from ODT.  ODT is a very simplistic monitor
that lets you modify memory and registers and start or single-step
through instructions in memory.

165000 is a common (but not the most common) address to put a ROM'ed
bootstrap at.  I'm guessing that when you halted it it was either doing
the self-test or waiting for an external device to come ready.

The "&" prompt I'm not so sure about.  It's possible that this is a
prompt
from the bootstrap monitor (some Emulex bootstraps will say that) or
maybe it's from the OS/embedded application.

>The machine is in a BA23 case and was a PDP11/23 I think, but has a PDP11/73
...
  CPU upgrade.
There is a full height ST506 hard drive reputed to be 30Mb in
size, which spins and makes all the right noises.
Any suggestions? 
What would help the most of all is an inventory of cards in the backplane.
If they're DEC cards they'll have a "Mxxxx" number on the handle. 
Third
party cards you'll probably have to pull to identify.  Also tell us
the exact position of each card in the backplane, and what cards are cabled
to what drives.

I suspect from the less-than-perfectly-standard bootstrap address of
165000 that you've got a third-party controller in there with on-board
bootstrap, though of course there an infinite number of permutations that
things could have been set up for!

--
 Tim Shoppa                        Email: shoppa(a)trailing-edge.com
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