I've had an Intel Plato Socket 5 motherboard from new - these had a soldered Dallas RTC DS12887. In the motherboard user manual they wrote that the Dallas module is expected to last 10 years, however the one on this particular board had a 1994 date code, and it only died some time last year. So they probably work a lot longer than the stated 10 years.

Personally I would rather solder a socket in the board and swap the Dallas RTC every 15 years than attempt this "surgery" with the CR2032 battery. Anyway that's what I would like to do with my motherboard if I find someone who knows how to do soldering!

So fully charged Dallas RTC's are available? That would be nice, but like you I'd need to find someone who can really solder.

EDIT: Here's another link showing the results of surgery. However this person was able to remove the chip and re-solder after the work:

http://www.classic-computers.org.nz/blog/2009 … attery-chip.htm

tincup wrote:

So fully charged Dallas RTC's are available? That would be nice, but like you I'd need to find someone who can really solder.

Yes, you can buy them on Ebay. They aren't exactly newly produced, but with using a socket you can just swap them in 10 years time.

Of the Socket 4,5 and 7 boards I own with RTC's only two have died. Rest keeps on with almost 20 years since they were new.

You can find some on ebay, but be careful about the date code on them - I've read stories of people buying twenty year old "NOS" chips and they were of course DOA.

You can also get them new from the manufacturer:

http://www.maximintegrated.com/

Update: Well, upon closer examination the RTS sure looked like it was not soldered on but fitted over some kind of socket. Sure enough gentle prodding with a mini screwdriver cleanly released the 24-pin battery. Everything is new to me with this 486...

So, if I wanted to retrofit a coin battery holder I could follow the instructions I've already linked to, but I think I'll take the easy route and source a replacement of recent vintage. EBay lists quite a few but as MM says - you have to trust the picture and the date code. I'll take my best shot...

In the meantime I sourced a fairly inexpensive replacement motherboard complete with ISA riser board, ESS audio backplate and front panel cables. Now I have backup parts for any future problems.

While it is a bit of shameless self-promotion, one potential alternative will be this:
Possible DS12887 drop-in replacement

While I wait for what I hope is a fairly new replacement battery to arrive I just may try my hand at the chop and solder mod on the dead RTC sitting here in front of me. Just need to pick up a coin battery holder and borrow a decent soldering iron from someone - the one I have couldn't melt it's way through butter.

EDIT: first of 2 Dallas RTC batteries I ordered arrived from China. It was printed with 2011 date markings, but registered "CMOS Battery Dead" at POST. One down, one to go.

Ahhh, up and running again. Procured a pair of fully charged RTC batteries of 2012 vintage, for $7 plus $2 postage. Thanks China!

But now it seems my crappy drive caddy has gone down...

Link ? (China etc...) 😀

This was the eBay item:
http://www.ebay.com/itm/1PCS-DS12887-IC-Dalla … =item43c655c73e

The $ was different when I bid - it was for 2 pieces. Nothing about it to tell you it was better or worse that any of the other offers. But I did get 2 IC's with the same date stamp and they are charged.