PDP11/84 continued

From: Doc Shipley <doc_at_mdrconsult.com>
Date: Sat Sep 27 16:03:00 2003

   After several hours with the 11/84 last night, it appears that I'm in
the same boat as Gunther with respect to the Unibus terminator.

   First off, in *any* configuration with an M9302 Terminator in A-B of
the last slot, the CPU hangs at boot at LED 77. I have plenty of G7273
NPG-grant continuity cards, as well as non-NPG knuckle-busters. Which
they are.

  I'm pretty sure my configuration of the card cage isn't right.
Here's the original layout (forgive any misalignment in the drawing -
Mozilla apparently translates tabs to whitespace, and not correctly):

        A B C D E F

|| M7677 - 11/84 Monitor ||
|| M8190-AE - CPU ||
|| M8637-BC - 1MB ||
|| M8637-DF - 1MB ||
|| M8191 - Unibus PMI ||
                || G7273 - NBPG ||
                || M7860 General Dev Interface? ||
                || M7860 General Dev Int. ||
|| M7819 - 8-Line Async ||
|| M7819 - 8-Line Async ||
|| TCU-150 - Custom serial splitter, NPG unkn. ||
                || M8526 - RX211 ||
|| UniB OUT || M7258 - LP11 Printer Int. ||


   The TCU-150 is entirely undocumented except for a couple of invoices
for etching and assembly. It's supposed to be part of a system of
splitting an available serial line into multiple comm channels, but
that's all I know. For whatever it's worth, the original configuration
map on the lid of the system unit is accurate, and appears not to have
been altered, so I'd guess that the backplane is in its original state, too.

   What I want is some variation of this:

        A B C D E F

|| M7677 - 11/84 Monitor ||
|| M8190-AE - CPU ||
|| M8637-BC - 1MB ||
|| M8637-DF - 1MB ||
|| M8191 - Unibus PMI ||
|| M7486 - UDA50-A ||
|| M7485 - UDA52 ||
|| M7521 - DELUA ethernet ||
                || M8526 - RX211 ||


   ...although the DELUA isn't strictly needed. Even without the DELUA,
with the last 5 C slots populated with non-NPG grants or with G7273 NPG
grants, I don't get a reasonable response from the RX02. And as I said,
with the terminator installed, the box just hangs at powerup.

   Can anybody tell me what I'm doing wrong?


     Doc
Received on Sat Sep 27 2003 - 16:03:00 BST