[colug-432] SPARC "EEPROM" Battery Replacement

[jep200404 at columbus.rr.com]

On Fri, 03 Apr 2015 13:22:30 -0400, Rick Troth <rmt at casita.net> wrote:

> On 04/03/2015 01:03 PM, Bill Schwanitz wrote:
> > ... dead eeprom battery ...

I had forgotten about those. Was it actaully battery backed up 
RAM? If I recall correctly, at least some had a conventional 
low power static RAM chip, maybe with some clock stuff, and a 
battery potted in epoxy to look like a tall 24 or 28 pin DIP chip. 
I might be confusing your EEPROM thing for what I messed with.

If one is desparate enough, one can use a Dremel to grind through 
the epoxy to the lead frame connections to the battery to 
disconnect the old battery and connect a new battery
(with a socket!!!). I think there was some trick for loading 
data into it by plugging into a live socket in a running PC. 

I did the Dremel thing for testing. I had a good battery, but 
needed to test software's ability to detect some bad battery 
status bit. Instead of replacing the battery, I put a switch
in series to it, so I could connect and disconnect the battery. 
If I cared more, I would have used a SPDT switch to select 
between using the good internal battery, and an external 
variable voltage supply (battery through pot) with voltage 
meter, so I could have tested the threshold. 

Oh well, not my problem. :-)