[SunRescue] Bad - new NVRAM/TOD??

[Harry Regan]

Just reporting back, though a couple of other folks have
said the same thing...  The M48T02 NVRAM chips work like a
champ in IPCs-- no TOD clock problems.  I got a couple of 
IPCs in, swapped in the M48T02 chip and bingo!  Nirvana!
Well, maybe not Nirvana, but the machine worked fine...

--- original message ---

Date: 3 Jan 01 08:17:18 EST
From: Harry Regan <harry.regan at usa.net>
To: rescue at sunhelp.org
Subject: Re: [SunRescue] Bad - new NVRAM/TOD??
Reply-To: rescue at sunhelp.org

Hi Steve--

Yeah, I experienced the same thing and posted a message about 
it in December.  Since then, I've found out two additional data 
points. I originally ordered 200 NS chip for my IPX from Mouser 
and got the TOD error you reference. I ordered a 70 NS version 
of the same chip (also from Mouser) and got the same results.

Then I ordered the 150 NS version of the M48T12 from JDR 
Microdevices (they don't carry the M48T02), and it worked like 
a champ. They're $16.99 each from JDR, rather than $12.80 from 
Mouser for the M48T02. Mouser also carries the M48T12 chip, also 
at $12.80, but I haven't tried it (yet). 

So, despite what the NVRAM FAQ says, it looks like the MT48T12 
chip is the one to use. All the chips I've been playing with are 
from the same manufacturer, so it's not a vendor problem.

The ones that did NOT Work:

Manufacturer: ST Label: M48T02-70PC1
Manufacturer: ST Label: M48T02-200PC1

The one that DID Work:

Manufacturer: ST Label: M48T12-150PC1

I will sware that I successfully used an M48T02 on an IPC a while 
back.  Anyone out there have an IPC with a dead NVRAM chip willing 
to experiment with one of these chips? I'll send a free chip to the 
first one who volunteers!

P.S. I have not found a way around the TOD Clock error. I even 
tried some kinky nvramrc gymnastics, but the machine would always 
blow back to the prom prompt.


___________________________________________________________________ 
---- Harry J. Regan
---- Phone: 202.310.2719 
---- FAX: 212.202.3923
---- harry.regan at usa.net 
---- hregan at lepus.com


____________________________________________________________________
Get free email and a permanent address at http://www.amexmail.com/?A=1