I debated whether this was actually worth adding as a shared project, as it is a really simple thing to build by itself. In the end I ended using them myself, simply because I kept forgetting which pin went were - and the last one I built was always inside an old PC by that point. With that out of the way, I should probably say a bit about what it actually is...

Going back to the golden age of IBM PCs and compatibles, there was a requirement for a RTC-chip in order to keep the time when the computer wasn't powered on - something that inevitably requires the presence of a battery! At one point you had the chip and some kind of battery next to it, but in order to make it more of a one-chip solution the battery ended up being sealed into the casing. And so we went from horrible leaking barrel-style batteries, to the DS1287 as well as the later DS12887. Originally thought to outlast the practical usability of the machines, but being into old computers simply isn't about being practical about things.

As for a short-term solution to my problem, I decided to build something out of a stack of DS12885 chips - mostly as those still seem to be available for purchase. To make it easy to assemble, you just put the board on top of the chip. Pins with suitable solder pads above them are then bent up and over, then soldered into place (use a bit of double-sided tape if you need to). The remaining component is a 32.768KHz crystal, and a CR2032 battery holder with loose wires to complete it. The battery holder might come as a surprise, but it's there to allow for a socket to be used below the chip without being in the way of any expansion cards (hide it somewhere if it annoys you).

When making a order of this PCB, make sure to specify a PCB thickness of 0.8mm, as that seems to be sufficient for this purpose. PCBWay will usually add an order number to the board, a spot for this information has been added to the back of the PCB - so make sure to select "Specify a location" when answering the question about removing product number.

NB! Included Gerber-files are slightly changed from the version shown in the pictures, mostly just to make it look a bit nicer.