[comp.sys.mips] Moby Magnum memory

mbr@lcs.mit.edu (Mark Reinhold) (03/23/91)

I have 32 4MB 80ns SIMMs, but I can't get more than 96MB to work in my Magnum
(the power-on memory tests fail).  I've tried sufficiently many combinations to
convince myself that no one chip is obviously bad, but that doesn't eliminate
the possibility of a bus loading problem or a broken SIMM socket.

Has anyone managed to get 128MB of third-party memory working in a Magnum?
Or 128MB of genuine MIPS memory?
--
Mark Reinhold                            mbr@lcs.mit.edu
MIT Laboratory for Computer Science      (617)-253-3538

rex@cs.su.oz (Rex Di Bona) (03/25/91)

In article <MBR.91Mar22124229@callebaut.lcs.mit.edu> mbr@lcs.mit.edu (Mark Reinhold) writes:
> I have 32 4MB 80ns SIMMs, but I can't get more than 96MB to work in my Magnum
> (the power-on memory tests fail).  I've tried sufficiently many combinations to
> convince myself that no one chip is obviously bad, but that doesn't eliminate
> the possibility of a bus loading problem or a broken SIMM socket.

We have two magnums with 32 memory chips in them. Both of these are at
104MB They have 24 by 4MB SIMMs and 8 by 1MB SIMMs. I have had machines
up to 128MB on both genuine memory, and third party memory (using 4.50).
I have used both NEC and Samsung 4MB SIMMs.

If you boot the kernel with the 'showconfig' option enabled what does
the kernel memory sizing routines tell you? What does the prom message
say is your memory size? Does the kernel say it's 128MB or does it stop
at 96Mb too? Does it fail reliably?

If you cannot get this to work, and I'm allowed, I have a modified
kernel which will give better diagnostics when it is booted showconfig.
If this is allowed under the licensing agreements we both have with
MIPS I could let you have a copy.  (Roger?)

> 
> Has anyone managed to get 128MB of third-party memory working in a Magnum?
> Or 128MB of genuine MIPS memory?
> --
> Mark Reinhold                            mbr@lcs.mit.edu
> MIT Laboratory for Computer Science      (617)-253-3538
--------
Rex di Bona (rex@cs.su.oz.au)
Penguin Lust is NOT immoral