PDP11/84 continued

From: Doc Shipley <doc_at_mdrconsult.com>
Date: Sun Sep 28 00:32:20 2003

Tony Duell wrote:
>>Doc wrote:
>> 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.

   Part of the problem was that since the NPG jumper goes on pins CA1 to
CB1, I thought the G727A goes in slot C. After discovering the mistake,
further thought and a look at a G7273 tells me that that logic was
screwed anyway. :(

> I thnik the problem is that you've moved the RX211 into a slot where the
> NPG jumper isn't cut. Put it back in the next-to-last slot, and put a
> grant continuity card (either type should work) in the last slot. Have
> all other slots dilled with G7273s for the moment (leave out the DELUA
> and the UDA50). See if you can get the RX02 to behave like that.

   Well, with only the RX211 installed in its original slot, the M9302
terminator properly installed, and G7273's everywhere else, the CPU
still hangs. With G727A cards instead of G7273's, the RX02 will boot an
RT-11 installation floppy.

> Once you've got that working, you'll need to check the backplane to
> remove the NPG jumpers on the slots where you put the UDA50 and the
> DELUA. Both are NPR/NPG devices. IIRC, the UDA50 is a 2-board set. You
> have to remove the jumper from the 'digital' card's slot, it doesn't
> matter about the other one, so you might as well take out both jumpers to
> avoid confusion.

   The above, and the fact that installing the UDA50 pair and trying to
boot DU0 hangs the box, tells me I'll have to pull the backplane and do
some snipping.

   Thanks *very* much for the help, everyone. Just getting a normal
boot off the RX02 validates the system and the backplane, and warms the
cockles of my heart!

   In other news, the PDP11V03-L that came with the 11/03 boots and runs
perfectly. It's not nearly as slow as I had expected, either.

   The friend who is helping with this and providing space for it all
was quite impressed with it. The 11/03 is several years older than he
is....


        Doc
Received on Sun Sep 28 2003 - 00:32:20 BST