First post, by Garrett W
2020 was a very rough year. However, if there's one positive aspect of it that I can find is that I got infected by the retro virus once again. Well, my wallet would have a different saying on that, but the free time/boredom chart showed a definite rise to unprecedented levels. In October, some family friend gave me 5-6 old PCs, including 486 systems with which I had never toyed around much, so I started diverging into even older systems, culminating in a search for a 386. So, somewhat recently I finally got my very own system, here are the specs:
UMC 82C481BF + 82C482AF based mainboard with Mr.BIOS EEPROM and 128K 20NS cache
Goldstar Prime 2C for my I/O needs
Cirrus Logic GD5422 1MB
3Com Etherlink III
Slow 1GB HDD (couldn't get my CF2IDE adapter going on this MB 🙁 )
I was running this system with zero issues at 40MHz, but then I hit them E-Bays and quickly bought a Cyrix based TI486DLC40 along with a Cyrix FasMath-33 (couldn't find a 40Mhz part), because why the hell not? I had heard that sometimes BIOSes might have issues enabling the L1 cache on the 486DLC CPUs, but I had never stumbled upon all the other issues that came with it. As such, since installing the chip, I've had a ton of issues and instabilities. Initially, I thought the FPU was to blame, what with the overclock and everything, but seeing as the same issues persisted even after its removal...
I'm using the most aggressive settings and timings possible in the BIOS, which were perfectly stable on the 386DX, so I thought perhaps something had to give, so I went ahead and used the absolute worst settings on everything, just to be sure. No difference. Then I read a bit on cache coherency with the L1 and L2 caches and it all started to make sense. As soon as I disabled both caches, everything ran fine, but of course performance is nowhere near where it should be. At this point, even enabling L2 cache solely will cause a crash or divide by zero error sooner or later.
I've tried a few utilities and suggestions seen in the forum, but I gotta admit I'm a bit in over my head, so I just cleaned my autoexec and config files to the way they used to be, made sure my Win3.11 setup was clean as well and will present them to you attached at the bottom. Any suggestions that should work for most systems that I could try on mine? Any help would be appreciated, as this system is a speed demon compared to similar ones online, I'm getting some real satisfaction from this 😜. Just for fun, here are some indicative scores from Phil's suite, from the tests I managed to complete with L1 and L2 cache enabled, even for a short while:
3DBench : 24.3 fps
PCPlayer : 6.2 fps
Doom (using FastDoom): 13fps
TopBench: 117 marks