PDP-11/23 Debugging

Ben Sinclair bensinc at gmail.com
Tue Nov 18 21:21:07 CST 2014

On Tue, Nov 18, 2014 at 5:24 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu>

> So, if the CPU checks OK, maybe the DLV11-J has a problem with interrupts?
> Is
> there a DL11 diag you can run on it? (If not, I can whip up a simple test
> to
> check it out.)

The diagnostics manual mentions this:


But, the only XXDP disks I have are the ones from AK6DN, and that test
doesn't appear to be on any of them.

>     > I have another memory board, but I know it's bad, so I can't try
> that!
> Probably the one you have passes the memory diag, though, right?

I've run a memory test program I found that's not part of XXDP, and I
believe it's fine, but is there a test in XXDP I could run? I don't see
anything in the XXDP manual related to an M8044/MSV11. Now that I think
about it, I probably should find a way to really verify the memory is

The MMU test from XXPP does pass, but I'm not sure if that also tests the

> If it's not an issue with the DL11 interrupting, it sounds like we may have
> to dig into that diag to find out what it thinks it's doing when it blows
> up.
> If I can get my tool-chain working (currently downloading the abs-loader
> isn't working right somehow), I'll see if I can figure out how to load it,
> and DDT along with it, and poke into it.
> Locating the fiche would be another way to go...
>         Noel

Ben Sinclair
ben at bensinclair.com

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