Sick RL11 controller help
staylor at mrynet.com
Sat Oct 28 18:01:49 CDT 2006
I have a PDP-11/34a UNIBUS system, and the RL11 controller just died on me.
I haven't a spare RL11 to diagnose it with, so I've been toggling in whatever
test programs I can find.
The RL02 drives I have, the cables and the packs are all verified good by
booting and testing them on an 11/53 system.
The symptoms are as follows:
o No drive will boot. CPU halts.
o Using vtserver, I can copy the first 8 blocks from any drive back to the
vtserver host, but then fails on block 8 with HNF (Header Not Found) in
the CSR. Always block 8 (blocks 0 thru 7 always read fine).
o A toggle-in oscillating head positioner test code (from the manuals) seems
to audibly indicate the head carriage is moving back-and-forth continuously.
o The machine seems otherwise unaffected. I can toggle in and test basic
machine functionality for memory, CPU, interrupts, etc.
It seems quite certain that I have a RL11 controller that has stopped working properly.
Not having any other UNIBUS disk systems or any way to boot XXDP, I can't do any further
The machine and disk were working fine, and I was even running diagnostics on it when the
My question is this: Is such a sector addressing failure at all common enough that
someone could suggest replacing one or more components on the RL11 controller before
I try to obtain a replacement and chuck this one into the trash?
Perhaps someone has a working controller they could sell?
Thanks in advance,
staylor (at) smedley (dot) mrynet (dot) com
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