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Subject: Bad memory suspected
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Date: Tue, 1 Feb 2000 00:02:20 +0100 (CET)
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From: wjw@iae.nl (Willem Jan  Withagen)
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Hi,

Being probably bitten again by some bad memory, I'm considering applying
some of my old (VLSI) testingskills to this. However.....

I'm in dire need of some hints, some because I haven't kept up with the
intimate details of Intel hardware, nor do I know how to get a lineair
memory space for all the fysical memory available in the system.

The starting problems are:
1) I'd like to do this als a loadable kernel module, so one would load this
module on the boot-prompt and let it eat away CPU time until it is rebooted.
Now is there a module example which I can use to get me an easy setup for
plugging inthe memory-test modules. Starting with simple things like
"walking 0 and 1's", but ending up with O(n^2) tests to check for
dependancies on surrounding values

2) Cache is a friend and a fiend in this: It helps fast execution of the
code, but prevents data really getting to the silicon. So all experience in
this is welcomed. Bluntly I can disable all caching (which would be nice for
starters), but once we get to the more complex testingpatterns CPU-cycles do
start to count.

3) PC memory layouts used to be a major art just by itself in the old days
when we still used DIP 4116's, how is that in the current time with SIMM,
DIMM, RAMBUS, PCI-bridges, ECC, .....
Any pointers to nightly reading material??

Thanx,
--Willem Jan

I once had a TRS-80 test run for 3 days, before it gave in, but then the
error was reproducable and pinpointed the actual chip to be replaced. Which
did fix the problem. 
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