Drugwash - the mod is not as difficult as it looks in the photos. I used a fine tooth Xacto saw instead of a Dremel and cut either side of the pins, 3/16 inch or so into the epoxy, then scraped the material away with a small screwdriver. The heat from soldering is confined. You can get lithium AA or AAA cells.

It wouldn't be (too) difficult if there wasn't another IC right next to the Dallas on the side that needs operated on. I don't have any precision tools, will have to find something appropriate. No problem with the replacement battery - a CR2032 (classic BIOS battery for newer PCs) would be fine and I do have a few dismantled boards where I can take the battery holder from. AA or AAA cells would be overkill - not even the two 286 boards I still have around use such large batteries. :-)

So many projects, so little time.  :-)

Plenty of time, not enought focus. And oblivion getting in the way. Growing old too soon.