PDP-11/23 Debugging

Ben Sinclair bensinc at gmail.com
Mon Nov 17 14:38:20 CST 2014

Now I'm confused again! If I setup the BDV11 to control the LTC interrupt,
should I have W4 in or out?

This information on the JKDBD0 test says it will halt and store information
in memory, and to refer to the microfiche to find out what happened.
However, it also says it will print that banner message, but I don't see
that. I believe it's not even starting the test, but I'm not 100% sure.

On Mon, Nov 17, 2014 at 1:55 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu>

>     > From: Ben Sinclair
>     > I did not have a jumper on W4, so I added one
> Err, adding jumper W4 _disables_ the LTC interrupt; see pg. 324-325 of the
> "Microcomputers and Memories Handbook (1982)". (Since you were apparently
> seeing LTC interrupts before, it makes sense that the prior state of the
> board had them enabled...) If you don't have that book, worth picking one
> up
> on eBay - full of all sorts of useful info.
>     > The test I can't run .. is the JKDBDO CPU test. When I try to run
> this
>     > one it doesn't print anything and drops me to ODT at 037526.
> Hmm. Probably need listings, or something, to figure out what it's unhappy
> about. The only documentation I could find online is the "PDP-11 Diagnostic
> Handbook", and various copies of the content there, and it's not very
> detailed. (BTW, it's probably 'JKDBD0', not "JKDBDO".)
>     > The BDV11 manual says they are controlled through a register via
>     > software, so maybe I'm just not running anything that sets them.
> That would be my guess too.
>     > The only boot rom I have on the BDV11 is a TU58 boot loader, so if
> it's
>     > up to some other boot rom to set that LED register
> More likely the system software, not the ROM.
>         Noel

Ben Sinclair
ben at bensinclair.com

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