[comp.sys.ibm.pc] Isn't Parity a Hardware Concept?

Isaac_K_Rabinovitch@cup.portal.com.UUCP (10/02/87)

Has anyone heard of an AT clone blowing up with a "PARITY ERROR" without
there being an actual hardware problem?  Can this result from software
accessing the hardware in a flaky manner?  I'd appreciate hearing from
people who have had similar problems.  I also appreciate hearing from
people who think that the idea is preposterous.

For those of you who like case histories, here's my specific problem.  I
recently bought a used Zenith 241 with a standard controller, a high density
floppy drive, and a double (360K) density floppy drive.  The system has
512K on the mother board, and an add-in card brings conventional memory
to 640K and adds 1 meg of extended (that is, nonLIMS) memory.

When I got the beast, there were parity problems with the extended memory,
but the integrator who sold it to me now claims to have replaced all the
bad chips.  The Zenith diagnostics seem to confirm his claim.

However, I still have troubles when I try to run Fastback (latest version).
Whenever Fastback tries to format a disk, I get ++++PARITY ERROR messages
and drop into the debugger.  Now Fastback is one of those programs that
goes off and does things its own way, so one's first thought is "another
cloneland compatibility problem, let's try some other software."  BUT.
A parity error generated by software?  Is that possible?  If not, then
I have a hardware problem that only Fastback collides with.

mvolo@ecsvax.UUCP (Michael R. Volow) (10/03/87)

We also had the same problem of Fastback blowing up on a Zenith 200
series AT clone, with the same "+++++ parity error" message.  Fast-
back loaded, began to run, and then zingo!!!  We don't know if this
is a Zenith problem or a Fastback problem.  I had the same problem
when I tried to run CopyIIpc (Central Point).  There has been a 
problem with Zenith's EMS board, but it was not in the machine at the
time.

--Mike Volow, Psychiatry, Durham Veterans Administration Medical Center
  Durham, NC, 27712             919 383 3568
  mvolo@ecsvax.UUCP