OK, here's what I did over the weekend. I reinstalled my extra 512MB of RAM to give me 1GB total with Win98SE and the computer recognized it, so I decided to try some suggestions given here and other forums, as well as ideas from that Tweak guide. For all these tests, my swap file was set to 524MB for min. and max., but this shouldn't matter too much because I was getting the same types of errors when it was set to 800MB in my earlier round of tests. Here's each group of tests I tried and their results:
#1. In System.ini file,
[vcache]
MaxFileCache= (tried 524288, 522240, 393216, 262144, 131072 and 65536)
[386Enh]
ConservativeSwapFileUsage=1
#1 RESULTS: 524288 exited Windows as soon as I started first map, then when I restarted I got the "Please enable Direct3D acceleration...." error. The other numbers gave me total lockup errors from just before starting the first match to 1 1/2 min. into the match with no clear trends.
#2. Tried disabling my DOS LEGACY drivers with the above MaxFileCache numbers.
#2 RESULTS: Each time I either got the game completely locking up, locking with the UT2003Build Critical Error, or the same above Direct3D error with no clear pattern.
#3. In System.ini file,
[vcache]
MinFileCache= and MaxFileCache= (tried same above values)
ChunkSize=2048
NameCache=4096
DirectoryCache=96
[386Enh]
DMABufferSize=64
PageBuffers=32
ConservativeSwapFileUsage=1
#3 RESULTS: Locking up from either starting match to as long as 2 minutes and 20 seconds into the match with either total lockup, UT2003 Build errors, or Direct3D errors as above. The longest I was able to play was with the vcache min-max set to 131072 and after 2 minutes and 20 seconds, I got the Direct3D error. Once again, no clear trends in the results.
#4. Once again as above with DOS legacy drivers turned off.
#4 RESULTS: Total lockups and UT2003 Build errors; although, I was able to complete my first map match in 3 minutes and 30 seconds, then start the second map and a lockup 1 minute into that one with 131072 as the vcache setting, then I got the UT2003 Build error. So, I guess you could say this was my best result overall for the weekend!
#5. As #3, but added MaxPhysPage=30000 to the [386Enh] section to limit the amount of RAM windows recognizes to 768MB (effectively running with 768MB instead). Also, the min-max vcache values tried were different (393216, 196608, 98304 and 65536).
#5 RESULTS: At 393216, I had an incompatible adapter error and the default desktop came up on the screen, WTF?! Matches ran for maximum of 6 seconds before UT2003 Build errors for the other values.
So, I'm done for now and plan on trying all this again once I reinstall Win98SE on this computer system (if ever, hehe). My guess is that I'll get XP in 8 months and install 10GB of RAM on my second system build in Feb. 2004 and be done with it. Since new games coming out lately seem to not run well in Win98SE (*cough* Unreal2 *cough*), then I'm sure I'll need XP for Doom3, UT2004, QuakeIV, etc. I'm glad other people have gotten this to work with 768MB and 1GB of RAM with Win98SE, but no luck here. For those of you that helped, thanks for everything!