Odd it has no cache TAG chip unless it is U34 (cannot read it). You should be able to add 4 more identical cache chips and probably have to change a jumper to get to 256k.
Too bad it has a Mr.Bios and not the original BIOS, ....did some digging but found not much so far....
Found some basic info on the Alaris Leopard Plus 486SLC2-66 computer: max 64Mb ram. upgradable to 512k cache. came with Microid 1.61 bios. 5 ISA, 3 VLB. 1 Para and 2 Serial ports. came with IBM 6324 14" monitor.

Awesome. Thanks Horun for the info you found. Appreciate you very much. I have 4 of the cache chips ordered, once i get them i will give it a shot and see if we can jump to 256k.

lowlytech wrote on 2021-07-17, 21:44:

Awesome. Thanks Horun for the info you found. Appreciate you very much. I have 4 of the cache chips ordered, once i get them i will give it a shot and see if we can jump to 256k.

Wish I could find more info on your Leopard Plus board, seems no one documented it and from archives Alaris Inc. quit building computers in 1995 (switching to video devices) and all tech info on them was removed from their website prior to 1996.
IBM has very limited info on it even though they manufactured it for Alaris, they do not have the jumper settings in their archives (have not found any yet)
http://web.archive.org/web/19961029032529/htt … om/about_al.htm
If you could take a better top picture of the motherboard (like your 20210716_182546.jpg but more centered and better over all focus) and possibly save the BIOS (use ROMSAVAT.exe from Getrom.zip) it would help.
As far as what jumpers do what: As far as I can decode from the board layout: JP6,7,8 are for cache size. JP1,2,3 must have something to do with CMOS. JP12, 13 have to do with adding a 486 cpu to the socket. Of course am probably wrong 😀

added: "Question: I have heard of IBM-made motherboards called "Azure," "Opal," and "Leopard." What processors do they use, and are they available as upgrades?
Answer: These motherboards are made by IBM for use in OEM systems. Azure used the Blue Lightning (486BL2/BL3) processors, while Opal contained the 486SLC2 processor. They were used by a number of OEM vendors. The Leopard motherboards were designed for, and supplied, to Alaris Corporation only. They used either the 486SLC2 or 486SLC3 processors, depending on the model. None of these motherboards were available directly to end-users; only as part of OEM systems."
from bottom of http://ps-2.kev009.com/pcpartnerinfo/ctstips/b01a.htm