Re: Memory tests

[dempson@actrix.gen.nz (David Empson)]

Wayne Stewart <waynejstewart@gmail.com> wrote:

> I acquired a few RAM cards and wanted to test them. For some like the
> Apple II memory card I used the self test but for the Applied
> Engineering cards I thought I'd use their RAM testing software because
> it shows which chip is bad. I decided to use a IIgs upgraded IIe, a
> ROM 01. First card I tried was a 1.5mb GS-RAM. The test showed most of
> the RAM as being BAD. So I decided to move the RAM chips that it
> indicated were good to the first bank and RAN the test again. This
> time it showed totally different chips as being bad. I put that aside
> and decided to test a ramfactor that had passed it's built-in self
> test. The software indicated that most RAM was bad. I'm now thinking
> that maybe the IIgs had bad RAM so I ran it's self test which it
> passed. At that point I switched to a different ROM 01 and both cards
> passed the test.
> I haven't used this IIgs much as it came with a bunch of stuff I
> acquired this month. I'm still thinking that there may be a memory
> problem in the IIgs. Any other suggestions?

The RamFactor has a single byte I/O register and three byte
auto-increment address register in the $C0nX space. If a RamFactor fault
is being reported in that IIgs, I'd be inclined to suspect some kind of
slot I/O access problem rather than a IIgs memory issue.

Did you try the test with the IIgs set to standard and fast speeds? (I
wouldn't expect that to be a problem, unless the RamFactor has some kind
of minimum recovery time between reads or writes. Never heard of such an
issue.)

Does the IIgs have an accelerator? If so, the problem might be related
to the accelerator's mechanism to slow down when accessing slot I/O
locations.

Are there any cards in other slots? If so, try removing them. One of
them might be interfering somehow. Also try the RamFactor in a different
slot in case you have a faulty slot. The slot must be set to Your Card,
of course.

For reference: the IIgs memory test only checks its built-in memory, not
anything in the IIgs memory expansion slot, but I wouldn't expect a
RamFactor memory test running in 8-bit mode to be touching anything
outside bank 0.

-- 
David Empson
dempson@actrix.gen.nz