As FulVal suggested, it can be done with dgVoodoo. I've just confirmed that, with it, software mode works fullscreen with the full-sized HUD and sepia effects. Here are instructions:
Note: The following is for DirectX 10 and later GPUs, since the dgVoodoo 2 wrapper requires it. For older, pre-2007 GPUs, follow the instructions at the bottom of this post for dgVoodoo 1.5, instead.
1. Download the dgVoodoo 2 wrapper
2. Extract dgVoodooCpl.exe
to your game folder. Don't extract the MS folder, itself.
3. Run dgVoodooCpl.exe
from your game folder.
4. Click the [ .\ ]
button in the upper-right corner to set the config folder to your game folder.
5. On the General
tab, set Scaling mode
to Stretched, keep Aspect Ratio
. That keeps the gameplay and movies in the intended 4:3 ratio (so there will be black bars on the sides on widescreen monitors) and seems to be necessary to get the nice sepia fade-in effect when maps first load.
6. Switch to the DirectX
tab and set Videocard
to dgVoodoo Virtual SVGA Card
(this is the key setting to force software rendering).
7. Remove the checkmark from dgVoodoo Watermark
at the bottom and click the OK
8. Run olcfg.exe
9. Select Direct3D [HW Accelerated]
and, preferably, the highest resolution that your monitor supports, then click OK
(If you're wondering what to set on the Advanced
page, it doesn't seem to me to make any difference when forcing software mode.)
10. Once you're in a level, press the minus (-) key to bring up the full-sized HUD (i.e. make the gold bar which says "ammo," "health," etc. appear at the bottom).
Note: When a level starts, you may get a warning message about failing to enable 3D acceleration. You can ignore it because you want it disabled to get software rendering.
Note #2: There's another method that involves adding LECDDRAW.DLL
to give you a "DirectDraw" option in olcfg.exe, but I found that it still requires dgVoodoo and limits you to no higher than 800x600 (with the method above, you can go up to 1600x1200).
Edit: Here are the instructions for pre-DirectX 10 GPUs:
1. Download the dgVoodoo 1.50 Beta 2
2. Extract dgVoodooSetup.exe
to your game folder.
3. Download and extract [url=http://jkdf2.com/files/ddraw_(hack_viewport3_clear2).zip]this ddraw.dll wrapper[/url] to your game folder.
4. Run olcfg.exe
and select 3Dfx Glide mode.
5. Once you're in a level, press the minus (-) key to bring up the full-sized HUD (i.e. make the gold bar which says "ammo," "health," etc. appear at the bottom).
If the game doesn't automatically run in software mode or not how you'd like, run dgVoodooSetup.exe and play around with the settings in it.