HDERR: the continuing saga

[Brant Cheikes]

Sigh.  Intermittent HDERRs continue to appear in my unix.log.  I
checked the power supply as Thad Floryan suggested; you couldn't ask
for more accurate voltage output.  A sample log entry:

HDERR ST:51 EF:10 CL:FFA1 CH:FF00 SN:FF0C SC:FF02 SDH:FF24 DMACNT:FFFF
DCRREG:94 MCRREG:D300 Tue Dec  6 03:20:14 1988

I even found:

HD:Spurious interrupt Tue Dec  6 10:56:05 1988

Would some kind soul with access to the HD controller specs please
post the meaning of all bits in these registers: ST, EF, SC, DCRREG,
MCRREG.  I understand CL = cylinder low, CH = cylinder high, SN =
sector, SDH = head.

If anyone has an informed opinion on whether it's the disk or the
controller (or ?) at fault here, I'd appreciate very much to hear it.
-- 
Brant Cheikes
University of Pennsylvania
Department of Computer and Information Science
brant at manta.pha.pa.us, brant at linc.cis.upenn.edu, bpa!manta!brant