[rescue] Axil-255?

[Katherine Strojny]

Thanks James and Jeremy for the help.

James Lockwood wrote:
> A picture of the motherboard, even a blurry one, would be a terrific
help.

Here:
http://kstrojny.home.att.net/axil255.jpg (725 KB)

James Lockwood wrote:
> What configuration are the memory slots (type, labels, locations)?  I
> haven't worked with a 255 but the 245 (which was a close relative) used
> pairs of 72-pin parity SIMMs.  The SIMM pairings may not be physically
> contiguous on the board.

Memory appears to have a label on the system board for every two slots.
You can almost read the labels in the jpg link above if you zoom in.  In
case you can't:

   Front edge
J0403        J0404
J0303        J0304
J0401        J0402
J0301        J0302
   Back edge

Here's an extract of what Jeremy sent from memconf for comparison:
        $simmbanks = 8;
        $simmsperbank = 1;
        @simmsizes = (8,32);
        @socketstr =
("J0300","J0301","J0302","J0303","J0400","J0401","J0402","J0403");

(Yes, a little different...)

I was going by the SS1+ board layout and assuming J0403/J0303 was bank 0,
J0404/J0304 was bank 1, etc.  Maybe that's wrong.  Anyway, with 6 SIMMs on
each side, it powers up to the PROM monitor.

The SIMMs are 30-pin, 9 ICs per SIMM (can I assume that means parity?).
Various mfrs.  ICs are labeled as follows:

Toshiba TC514100ASJ-70 JAPAN 9219HCK  (4 of these)
(V-like logo) 9203 V53C400K70  (3 like this)
OKI JAPAN M514100A-70SJ 2492277 9A9Z  (2 of these)
(logo) KOREA 218Y KM41C4000AJ-7  (one left, the other one was the
overheating culprit)
OKI JAPAN 9A9Z M514100-80J 91105578  (4 of these)

The first four above are of the form shown on top in the following link.
The last type has a taller form shown on the bottom. Here's the pic:
http://kstrojny.home.att.net/simms.jpg (598 KB)

Jeremy RJ Towers wrote:

> You should simplify the board as much as possible, the memory is added
one at a time. Start with only the working 32mB module.

Sounds like good advice.  I tried to follow it, but unfortunately, I'm
still trying to figure out how to get the monitor to start with any fewer
than 12 SIMMs installed (6 on each side).  If I power up with fewer than 12
(like 10 or 8 or 1 or 2), I get memory errors (indicated by Compose light
on kbd, and the monitor never comes on).  Like I said, I don't know if I
can assume the memory banks corresponds to SS1+.  Starting to think they
don't, or they do but something got fried by the overheating SIMM.  Lemme
keep working on it.  Not sure if I need to be adding/removing in pairs or
what.

Any further insight is much appreciated!

-k