Hi all! First post for me, though I've gotten a lot of good information off the VOGONS forums over the years.

I have recently assembled a win98/DOS gaming machine. It's working nicely in win98se, but I'm having problems with EMM386 under DOS (the one that comes with 98se).

First off, relevant hardware specs:
Chaintech 6BTM0 (440BX) with 500MHz P3 Katmai, 512MB RAM, TNT2, HighPoint HPT374 PCI IDE, 3c905 ethernet, vibra16 ISA

The problem is with the PCI HPT374 controller. When I boot the machine from it, EMM386 causes freezes during boot and/or disk errors in DOS (which one it is depends on what other drivers I load, it seems pretty random). If I remove the HPT374 and boot from onboard IDE, everything works fine. However since I have an SSD (through SATA-IDE bridge) in the machine, I'd really like to get it working so I can have UDMA/133 instead of the UDMA/33 the onboard controller is capable of.

If I don't load EMM386, DOS works well with the HPT374. I can load HIMEM and any other drivers, run games, etc. Only EMM386 causes this problem. I've tried with a minimal config.sys like so (autoexec.bat is empty):

1DOS=high,umb
2DEVICE=C:\WINDOWS\HIMEM.SYS
3DEVICE=C:\WINDOWS\EMM386.EXE RAM

With this, the machine boots to a prompt. 'dir' works. 'cd windows' works, but a 'dir' in there causes a disk read failure error. 'cd games' from the root also causes disk read failure. Again, everything works if I remove EMM386, the filesystem and disk are fine.

I've tried excluding various address ranges from EMM386 using the x= parameter with no luck. The HPT374 has option ROM mapped at db000-dffff, excluding that made no difference (not surprising, EMM386 already scans for option ROMs and this one has a valid header).

I tried installing FreeDOS and it seems to work well with the out-of-the-box HIMEMX + JEMM386 configuration, I played some games there and it was stable, but unfortunately some of the games I wanted to try didn't work (not sure if it was JEMM386 or something else in FreeDOS), so I don't think that's a good choice for DOS gaming. Strangely, using HIMEMX and JEMM386 under MS-DOS using the exact same parameters as FreeDOS used causes similar lockups as regular EMM386.

Any ideas would be appreciated! I can run DOS with the onboard IDE controller, but would really like UDMA/133 for win9x, and I don't want to swap cables around all the time.