1 Sep
2011
1 Sep
'11
1:43 p.m.
Sounds like the software has a problem rather than the
hardware. I looked
back at earlier posts; you said you tested the RD53 in a MicroVAX 2000,
and
the RQDX3 in a BA23 uVAX II. But did that test use
the same
RQDX3 with the RD53 in the uVAX II? I /think/ the format put on an RDxx
by
any revision of RQDX3 is the same, though new firmware
might change things
like RCTs in ways not transparent to old firmware. But the format used by
RQDX1 and RQDX2 is quite different to RQDX3 and I wonder if the drive is
the
"wrong" format? Isn't a uVAX 2000 the
same format as RQDX1/2?
The format did occur to me, but I thought that being readable in a 2000 it
would be OK in a II since the 2000 came later than the II. I have not
low-level formatted this RD53 as it worked in the 2000 without issue once I
had unstuck the heads. I will try the problem RD53 in my working II and see
if it is readable there. If not then I'll reformat the RD53 in the 2000
because I did this once before on an RD53 that I use in my working machine.
The last possibility I can think of is that there are
a few active devices
on an
M9058. They're mostly Schmitt triggers and
open-collector inverters used
to
buffer signals from RQDX to drive (and v.v.), but some
are differential
buffers
for the MFM data. Maybe one of those has gone.
You could of course test the M9058 in the BA23. Just ignore the BA23's
normal drive cabling and connect the RQDX in the BA23 via the 50-pin cable
to the M9058, and cable the drive to that as if it were in a BA123. The
M9058
has no connections to the backplane except for power
and won't interfere
with anything else.
If the formatting things above do not work I will try this. I am also hoping
to borrow an M9058 from a friend, that may also help to narrow down the
problem. There are not many ICs on the M9058 and most of them look to be
easily replaceable, but I would need to diagnose which one is the faulty
one.
Regards
Rob