Andrew@cup.portal.com (andrew scott lagodzinski) (12/16/89)
HELP!!
I have been upgrading my 512K RAM expansion board to 2MB. I removed all
of the old chips, and installed augat sockets. I also cut the 3 hard wired
jumpers and installed 'real jumpers' which I moved to the 2MB position. I
also cut a trace and replaced it with a 33 OHM (1/2 Watt) resistor. I was told
about this stuff from Thad at one of the recent AT&T user group meetings.
So far so good you say? Well last night I installed the new chips
(256K X 1 120ns, HM50256P120). Today I installed the board in my 3B1, the
far right slot if you are facing the front of the machine. I turned it on and
waited to see if my handy work was any good. Upon booting, I got past the
loader screen ( whice didn't say anything about the expansion RAM) and to the
screen which has the dotty background. I then recieved a PANIC message.
#NMI (parity error in unmapped page) at 0 X 90004 (*hpte: 0 X 12D1)
panic: Unknown Bus Error
well I thought I would reboot and run the diagnostics on the RAM. Doing so I
started running the test.
EXPANSION MOMORY TEST
Adress Connection Test
Test will begin at 200000, end at 27FFFF
Adress Connection Test
Test will begin at 280000, end at 2FFFFF
Adress Connection Test
Test will begin at 300000, end at 37FFFF
Adress Connection Test
Test will begin at 380000, end at 3FFFFF
Data Bus Test
Test will begin at 200000, end at 27FFFF
Testing .
** ERROR **
Test : Expansion Memory test.
Subtest: Data bus test(walking 1's)
Pass : 1
Error : Momory error as Address 0: Wrote 1; Read Back 101.
Enter y [Y] to Abort, Return to continue:
Pressing return gives the same with the address incrimented by 8. Does
anyone have any clues as tto what might be the problem.
System is a 3B1 with 2MB mother board (p3..p5) 40MB HDD, 3.51 OS.
Could some one possibly send me the docs on how to do this mod the correct
was. I believe these are from John Milton.
Thanks....Andrew
Andrew Lagodzinski andrew@cup.portal.com (OR) ..!sun!cup.portal.com!andrew
413 Pinehurst Ave
Los Gatos, CA 95032
Home: (408) 371-7205