Parity error on AMI Mark IV motherboard

[Stephen Hite]

  I got a 33-386 AMI motherboard 2 weeks ago and it's been working well
on Interactive 2.2 with the cache on and off except for one peculiar
thing:

   I've got a 50-50 chance of getting a parity error during the system
   shutdown with "powerdown -Y".  The address of the parity error,
   in particular, is 0x0023e4fe, whatever that means.

  My configuration is:

     ISC 2.2 with 2.2 development system
     33-386 AMI Mark IV motherboard
     Perstor card as primary with 2 MFM drives attached
     Adaptec 1542b as a secondary with a Seagate ST-296N attached
     8 meg of SIMMs at 80ns
 
  Does anyone have a clue as to why this would happen *only* on a 
powerdown?  This is really strange because the Mark IV is considered to
be one of the most reliable motherboards you can buy for any OS you choose
to run by many netters and dealers I've talked to.

  If I was getting a parity error during "normal" operations, I would be
tempted to blame the seating of the memory strips but this is not the
case.

  Thanks for the ideas!

P.S.  Besides the new motherboard, the only other things that are new are
      the 1542b and the Seagate SCSI drive.  

------------------------
Steve Hite
shite at sinkhole.unf.edu 
      -or-
...gatech!uflorida!unf7!shite