• Please review our updated Terms and Rules here

PDP-11/23 plus rebuild/memory error

P

pizzaengineer

Experienced Member
Joined
May 10, 2015
Messages
84
Location
Leominster, MA
I have some pieces and I'm trying to put together a working PDP-11/23 plus. I have a BA11 enclosure with H7861 power supply and a H9276-A card cage. The sticker on the card cage says Option 11/23B. I purchased this enclosure with no boards in it.

I bought some modules and the CPU board is a M8189 and the memory board is a M8067. The CPU board is in the top slot and the memory board is directly below it. When powering it on the run light comes on for about 5 seconds and goes off and I get this output:

KDF11B-BJ ROM V1.1
ERR 1 NO MEMORY
ERR 6 TRAP 10
173414
@

Before I begin troubleshooting the memory error could someone please tell me if this is a supported configuration? I attached some pictures of the setup. Any help would be appreciated. thanks.
 

Attachments

  • P_20160828_141151.jpg
    P_20160828_141151.jpg
    95 KB · Views: 14
  • P_20160829_152008.jpg
    P_20160829_152008.jpg
    94.2 KB · Views: 13
  • P_20160829_152021.jpg
    P_20160829_152021.jpg
    99.1 KB · Views: 12
  • P_20160829_152035.jpg
    P_20160829_152035.jpg
    94.3 KB · Views: 12
  • P_20160829_152044.jpg
    P_20160829_152044.jpg
    102.8 KB · Views: 14
I don't see why it shouldn't be, as long as, as Al suggests, the mem board is jumpered correctly.

I'd start by removing the RAM board to see which which board gives the error. Perhaps it's an ABAB backplane? I can never remember which is which.
 
pizzaengineer said:
I have some pieces and I'm trying to put together a working PDP-11/23 plus. I have a BA11 enclosure with H7861 power supply and a H9276-A card cage. The sticker on the card cage says Option 11/23B. I purchased this enclosure with no boards in it.

I bought some modules and the CPU board is a M8189 and the memory board is a M8067. The CPU board is in the top slot and the memory board is directly below it. When powering it on the run light comes on for about 5 seconds and goes off and I get this output:

KDF11B-BJ ROM V1.1
ERR 1 NO MEMORY
ERR 6 TRAP 10
173414
@

Before I begin troubleshooting the memory error could someone please tell me if this is a supported configuration? I attached some pictures of the setup. Any help would be appreciated. thanks.
Click to expand...

This is the correct way to set up the machine with only these two cards. I would check is to see if the memory board maps the to the lowest address change (0->Memory Size of Card). While halted, see if you can use ODT to check if any of the memory is addressable at low address 0 and saves data deposited to it.

http://scandocs.trailing-edge.com/micropdp11-volume1_system_cpus-EK-245AA-MG-001.pdf explains the error messages.

See http://www.psych.usyd.edu.au/pdp-11/hints.html for some simple checks to run on the machine. Its mostly for a PDP-11, but Q-Bus debugging is mostly similar.

Jerry
 
pizzaengineer said:
I have some pieces and I'm trying to put together a working PDP-11/23 plus. I have a BA11 enclosure with H7861 power supply and a H9276-A card cage. The sticker on the card cage says Option 11/23B. I purchased this enclosure with no boards in it.

I bought some modules and the CPU board is a M8189 and the memory board is a M8067. The CPU board is in the top slot and the memory board is directly below it. When powering it on the run light comes on for about 5 seconds and goes off and I get this output:

KDF11B-BJ ROM V1.1
ERR 1 NO MEMORY
ERR 6 TRAP 10
173414
@

Before I begin troubleshooting the memory error could someone please tell me if this is a supported configuration? I attached some pictures of the setup. Any help would be appreciated. thanks.
Click to expand...
I have the same issue. My M8189 displays the same message. I am not sure if the problem is coming from CPU or the memory board (M8067). Had you figured out the issue ?
 
cmao said:
I have the same issue. My M8189 displays the same message. I am not sure if the problem is coming from CPU or the memory board (M8067). Had you figured out the issue ?
Click to expand...

A few weeks ago i also had been testing an 23+ with some mem.
I got the same error message. This happened during testing an 3rd party 256k board. A set of 2 in an antistatic bag, wrapped together with some wire over 2 handles.
I put only the 2nd module into the chassis - et voila - no error message, testing 256k 1 2 3 4 5 6 7 8 9.
Added the other module - testing 512k 1 2 3 4 5 6 7 8 9 - all good.

So i assume your memory is not confiured right, it may eventually be defective; but i don't think so.
Up to now i also didn't have a defective cpu board that acted this way.
hth
 
Chiming in with my 2¢, since I had the same issue with a similar config:
  • 9273 9 slot 18 bit Q/CD Backplane
  • KDF11-BA M8189 CPU card
  • MSV11-P M8067-LB 512KB Memory Board
steps taken:
  • I changed the starting address on the card to match my system
  • I removed the W1 & W2 0 ohm grant continuity resistors from the RAM card (correct for Q/CD backplanes)
  • I wired the 19th bit bus on the backplane across the first two slots, thinking maybe the error was because the the full address space of the RAM card wasn't present, and that what was causing the error (I'll go back and make this a full 22 bit backplane at some point).
I was getting the exact same error as reported above until I jumpered the RAM card for an 18 bit system. I suppose if I added all remaining buses on the backplane, I may not have had to do that. I'll confirm when I go back and rewire it, but for now, 256kB will keep me moving forward.
 
Yes, if you have a 22 bit memory board, but only an 18 bit backplane or 18 bit CPU you are in for trouble.

Everything needs to either match or be configured as the lowest common denominator.

Dave
 
The KDF11-B should support the full 22 bit address space though, right? I just need to fill out the rest of the data/address lines on the backplane. Any reason to extend those lines down the full set of slots, or can I just do the first few slots, assuming it's only used for RAM?
 
It depends upon what cards you are planning to use in your backplane of course.

If you plan to install a disk controller or a network card, they will use DMA, so they will require the additional address bits also.

You can do a few and add to them later...

Dave
 
You must log in or register to reply here.
Back
Top