14 Oct
2006
14 Oct
'06
5:22 p.m.
----- Original Message -----
From: "Chuck Guzis" <cclist at sydex.com>
To: <cctalk at classiccmp.org>
Sent: Wednesday, October 04, 2006 11:42 AM
Subject: Re: 486 EISA system
Just getting back to this project (seems I have been getting too many things
in lately). Anyway the 2 battery parts on the motherboard are: Dallas
DS1225Y-200 and ST micro MK48T87B-24. Is there a link to the discussion (or
website) on how to rig a lithium coin battery to this particular part? I
have a dremel, battery holder, and plenty of batteries so this should be
easy enough. Can the ST Time keeper RAM) chip also be rigged in this way (is
it the same part as the DS1287 mentioned above)?
On 10/3/2006 at 9:08 PM Teo Zenios wrote:
>Another Ebay find came in today, a 486 EISA motherboard and 5 cards.
>
>The motherboards seems to be this model:
>http://artofhacking.com/th99/m/U-Z/31111.htm , but I can't find a company
>name on it anywhere. It has 8 EISA slots seems to be setup for a 486 DX.
>it looks like there are 2 DALLAS real time clocks on it, and the machine
>complains the eisa config battery is low. Are there any cheap hacks to
get
around this?
Only one of these is an RTC chip, the other (DS1225V) is an 8Kx8 NVRAM. I
wonder if it might be simplest to replace this one with a similar FRAM
(Ramtron FM-1608) and be done with the battery issue, at least on the one
chip. The Ramtron chip is also cheaper than NOS DS1225Vs, BTW. You might
also be able to carve into the encapsulation with a Dremel to get at the
lithium cell as a very cheap dodge.
As far as the DS1287 RTC, it's been discussed on the list before (you can
carve into the epoxy and tie into the lithium cell contacts, or you can
just replace the chip).
http://www.maxim-ic.com/appnotes.cfm/appnote_number/503 has notes on
replacement.
Cheers,
Chuck