Doom & Build Engine games on Virtualbox

Yes, I know there are great source ports for Doom-engine games but I was kind of feeling the itch to play these in a true (or close to true) DOS environment via virtual machine. I know there's DOSbox but build engine games like Blood 3D can't be run at full speed at the highest resolutions (1280 X 1024). Has anyone tried these games using FreeDOS and VirtualBox? Someone claims on the GOG forums that Blood 3D runs at 100 FPS (!) on VB! Checked out setup guides on the net for setting up VirtualBox with FreeDOS but none are detailed enough to get 32-bit DOS games running with soundblaster.

cough, software rendering a build game at HD resoutions with no game engine hardware acceleration, will remain slower even if the host emulation system has hardware surfaces, because they need to be updated and uploaded to the gfx card for every redraw after the software renderer filled a buffer.

However, you COULD open the dosbox configuration cfg which is easy to find in the windows 8 start screen, or the XP and 7 menu bar, and change the graphics renderer to opengl by example to test if it is faster. on modern fast graphics cards this should at least improve the speed of upscaling the images.

Some years ago i played Dark Forces on FreeDOS on Microsofts Virtual PC. Runs smooth and without any problems.

The one and only time I tried to set up an "oldschool" DOS system via VB, my impression was that there was a GFX and sound bottleneck, even at plain VGA resolutions. It would ace CPU tests, as if you ran pure DOS on your Core i7 or whatever, but anything actually pushing graphics to the screen would be underwhelming, while even real-time sound emulation was less than stellar (choppy, laggy, etc.)

Makes sense, if you consider that VB is not designed for guaranteed real-time responsiveness and precise timing (unlike DOSBOX), which is required for games.

Thanks for the replies. Well, I did experiment with the OpenGL mode under DOSBox and found it plays Blood 3D (the most graphics intensive Build engine game, I think) decently at 1024 X 768 with between 60 and 80 FPS, which is very acceptable to me. The graphics whore in me of course wants to push it to the max and try to get 1280 X1024 but it starts to chug at that resolution at an average of 45 FPS. I was also thinking of turning an old 1800 Mhz machine I had with an ancient ATI Pro 9800 video card (my current system is i5, GTX 660 Ti-based) into a real DOS machine - I have an old Soundblaster 16 lying around and a free ISA slot on the motherboard - to use just for the more demanding first person shooters but decided that DOSBox is good enough providing I don't get too greedy with the resolution.

Now if only the source code for Blood 3d was released we could get a decent source port going for it.

I wonder how many folks end up missing the CPU Cycles option that DOSBox provides (and if this is a case of that). Sometimes things that are slow out of the box (heh) can be insta-fixed by bumping up the cycles, so I'd say try that first if you haven't yet.

On an semi-related-but-probably-unhelpful note, I did manage to get Doom and Blood up and running on my FreeDOS netbook thingy I hacked together a while back, though sound doesn't work since there aren't any drivers for that PC's particular audio chipset. I don't recall doing anything out of the ordinary to get the actual game to work (aside from maybe explicitly disabling sound in the setup tool; it's been a while so I can't recall).

Xaser said:

I wonder how many folks end up missing the CPU Cycles option that DOSBox provides (and if this is a case of that). Sometimes things that are slow out of the box (heh) can be insta-fixed by bumping up the cycles, so I'd say try that first if you haven't yet.

When I first started playing around with Dosbox I had noticed this being an issue in Wolf 3-D. It was strange, Doom ran full speed but I got like.. 10 fps in Wolf 3-D. Turns out Doom was triggering Dosbox to run the cycles at max but Wolf 3-D was not.

DOSBox automatically sets cycles to "max" when any DPMI program is being used.

I like more Dosbox (which is more accurate with CPU cycles). Tried once with virtualbox + Freedos / Windows 98 and the emulation speed was too high IMHO.

If you are curious you can try PCem, which can emulate a full Winchip CPU (or 386 and 486 clones, and if you compile the software for yourself you can emulate Intel Pentium CPUs) and the usual stuff, but the software is an alpha so the emulation speed is pretty slow (tried Win 98 on an emulated Pentium 166 and DooM 2 was unplayable)

chungy said:

DOSBox automatically sets cycles to "max" when any DPMI program is being used.

I don't think that really puts games like Blood in the right framerate though.

The problem with anything using dynamic CPU speed (and with emulators, in general) is that they tend to fuck up the games' built-in speed measurement mechanisms.

For example, a game might think the emulated CPU is fast enough and set its own (internal) delay too high, but only base this on a short test loop, which doesn't really make use of the emulator's full features (video output, sound etc.) or is heavily optimized by the emulator, and so the measurement is meaningless and misleading.

Setting the CPU cycles higher afterwards won't help much.