Non Volatile RAM checksum error!!

[Jeff Miller]

	I have had this repetitive problem with my SGI 4d/20 system that
I am rebuilding. Every time I try to boot, cold-start or reboot the
system, I get the following sequence of events:
(Actually, I usually get just the error message, with some or all of
the other stuff. The following is what I always get after powerup)

----------------------------------------------------------------
Console DUART test                      PASSED
Memory walking bit test                 PASSED
Memory address uniqueness test          PASSED

Non-volatile RAM checksum is incorrect: Initializing the non-volatile
  RAM parameters.
Interrupt mask registers test           PASSED
Graphics subsystem test                 PASSED


Non-volatile RAM checksum is incorrect: Initializing the non-volatile
  RAM parameters.
----------------------------------------------------------------

	I suspected that the problem might be a low lithium battery, but
my DVM quickly cleared up that question. Besides, my clock keeps *perfect*
time, even with the power off for 2-3 days (more, perhaps, but that is about
as long as I care to leave it off 8-)

	I suppose that this could be a software problem, since I have not
been able to find any information about how to initialize the NVRAM in the
limitted number of manuals that I own. My problem is that the system
keeps telling me that it is, "Initializing the non-volatile RAM parameters,"
and yet the system complains that the parameters have not been initialized.

	A friend said that the problem might be a bad NVRAM chip on the
motherboard. Can someone tell me whether or not the NVRAM is really an
EEPROM or just simply a battery-backed CMOS static RAM? Perhaps it is
combined with the clock/calendar chip, as it is with some of Motorola's
clock chips. (The clock chip in my system happens to be made by National
Semiconductors --> DP8572AN <-- I have no spec sheet on it...)


	Any comments, solutions, remarks, etc. would be GREATLY
	appreciated!

jcmiller at hydra.unm.edu