Good post - thanks a lot, and welcome to Vogons!

I knew if you had cache chips on the motherboard that those were fake but if you have a module in the slot that should be real.

I beleive they are all the same PC Chips motherboards with different names (PC Chips, Elpina, Amptron, etc). The M919 is somewhat distinguished among 486's as being the last made 486 motherboard, though certainly not the best. It is the only 486 motherboard I've seen naturally with 1997 dated chipsets (although I soon plan to have MB8433's and HOT-433 w/1997 chipsets).

I actually bought a 486 PC new in Jan 1997 because I couldn't afford a Pentium at the time. It so happened to be the M919. I found the cache modules online a few years later.

I have one of these boards and I can definitely back up the claim that the cache module helps performance. I installed Win98SE and the difference with/without the module is very noticeable.

I see L2 cache modules for other computers/printers/whatever online and I can't help but wonder if any of them are compatible with the board. I was thinking of contacting a few companies to see if they have anything compatible, or failing that, find someone who can custom-make them at an affordable price.

I see L2 cache modules for other computers/printers/whatever online and I can't help but wonder if any of them are compatible with the board. I was thinking of contacting a few companies to see if they have anything compatible, or failing that, find someone who can custom-make them at an affordable price.

Supposedly not, there's been quite a bit of discussion about this over the years... they were apparently a proprietary pipeline burst module specific to the M919, not the COAST modules that were used on Pentium boards that look almost identical.

At least I tried a COAST module from a socket 7 board in my M919 when I had it and the machine wouldn't power on at all.

RG100 posted this link earlier in the thread http://motherboards.mbarron.net/models/486pci/m919v3.htm which will answer any further questions about the cache.

If you have the cache module would you mind taking some speedsys benchmarks and posting the graphs?

The Ultimate 486 Benchmark Comparison was done with a 1997 M919 and a cache module. They never did make a pipeline burst cache module for the M919; they all are standard asynchronous SRAM modules. The official manual states that pipeline burst would be available in the future, but never was. I think it was a marketing ploy. The official manual (which I have a copy of) also mentions the board supports 128, 126, 512, 1024 KB SRAM modules, but I have only ever seen 256 KB modules and doubt the 1024 KB modules were ever made.

There is a photo of the M919 module in the Ultimate 486 Benchmark Comparison thread, first page, where all the downloadables are. I tried 4 different Pentium-era COAST modules in the past, but none of them ever worked.

McMick wrote:

I have one of these boards and I can definitely back up the claim that the cache module helps performance. I installed Win98SE and the difference with/without the module is very noticeable.

I see L2 cache modules for other computers/printers/whatever online and I can't help but wonder if any of them are compatible with the board. I was thinking of contacting a few companies to see if they have anything compatible, or failing that, find someone who can custom-make them at an affordable price.

It's a proprietary cache module. Mechanically it looks like a COAST module, but electrically it is different. You might damage the motherboard trying to put a COAST module in. Unfortunately, if you didn't get one with your motherboard they are very hard to get individually.

I realize it's proprietary, that's why I was wondering if one could be custom-made. I mean, there's proprietary and there's proprietary. I wouldn't wonder that every piece the stick is made of is available seperately and that they all just need to be brought together by someone. Not me, of course, 😀 but someone.

That said, there are 256kB asynchronous write-back cache sticks that are advertised for printers and soforth, which may have nothing to do with COAST modules and may be potentially pin-compatible with the M919. But I'm not going to order every type there is and test the theory, obviously. What would be better is if someone can figure out a schematic of the stick and compare it to other products to see where the differences lie. Then it might be worth plonking down some "cash" to buy some "cache" sticks to test with. 😁

I don't doubt that the bad one I have can be repaired, but since the chips are surface-mounted, that leaves pretty much 0 chance that I'll be the one to fix it. I'll probably throw it up on ebay and see if I can get a buck or two out of it.

EDIT: I found a datasheet which describes the SRAM chips used:
http://html.alldatasheet.com/html-pdf/123446/ … /1/N341256.html

Here are the SRAM chips used on the green module:

http://www.ardiehl.de/eprsim/UM61256.pdf

EDIT: My bad one uses Alliance chips:

http://www.datasheetcatalog.org/datasheet/All … tor/mXususx.pdf

Sure it can be made, you just need a PCB printer and SMD station.

There are some 8 ns pieces in that datasheet.