Ah, I understand now. Thanks for correcting me on that before I spread more bogus information! By the way, the Dallas DS1387 is simply a DS1385 with an internal battery. They literally just bent some pins up on the DS1385, plonked a battery on there, and then encaptulated it in expoxy. If you can find a DS1385, you can essentially make your own maintainable DS1387.
I looked up the motherboard, and the original diagram shows a symphony SL1287 in that socket, which is essentially a rebranded Dallas DS1287.
You seem to have the same motherboard being discussed in this thread: Symphony 80486 VLB motherboard
The motherboard info page is this one: https://stason.org/TULARC/pc/motherboards/U/U … VS486F-3VL.html
Unfourtunately, I could not find the original user manual, so it was most likely one of thousands of generic motherboards produced over the years. I would start with trying a Dallas DS12887 to see if it works, most of the time it's a drop in replacement for the DS12887. There are some occurrences where it does not work, however, so your best option might be to go the 1287 + dremel route.
If you wish to find a replacement 1287 to hack on with a dremel, ebay is your friend. Same with the 12887, that's where I got mine.
Keeping track of all those model numbers is a pain, 🤣.
"And remember, this fix is only temporary, unless it works." -Red Green