SCUMMVM port for DOS

K00L-A1D · Post by **K00L-A1D** » Thu May 26, 2011 9:14 pm

I am doing a study on old games and their system requirements. I would like to test a lot of old games and run them on old machines and see what the actual requirements are for the specs. I would like to take a computer with lots of RAM, take a computer with a fast CPU, see if they will run....

I would appreciate if someone could give me a DOS exe for scummvm.
Yes I would like to run scummvm in dos, and see how that would reflect the system requirements, if this scummvm, has made the requirements larger or lesser. What do you think? and could anyone help me?

Post by **eriktorbjorn** » Fri May 27, 2011 4:17 am

As far as I know, there is no DOS version of ScummVM. The "standard" desktop version of ScummVM uses the SDL library for graphics, sound, etc. and I haven't ever heard of anyone porting SDL to DOS. So making a DOS version of ScummVM would presumably mean writing an entirely new backend, just like when porting ScummVM to a new platform.

The standard version of ScummVM can probably have a lot higher requirements than the original game did. After all, we have to simulate a 256-colour palette, some of the sound hardware, etc. Of course, a DOS backend could possibly go back to using that hardware direcly. Then again, what would the purpose of a DOS version be? Would people actually use it to play the games, or would it be just an experiment? I can sort of imagine someone porting ScummVM to DOS for his own amusement, but I have much more trouble imagine anyone doing it just to satisfy someone else's curiosity...

E-Male · Post by **E-Male** » Fri May 27, 2011 5:08 pm

You could try running the Windows version with HX DOS Extender:
http://www.japheth.de/HX.html
(if that works, please report back)

K00L-A1D · Post by **K00L-A1D** » Sat May 28, 2011 3:57 pm

To Erik,

I was not asking someone to make this DOS port, I have heard it was already made. I was curious as to what you would project if the system requirements of a DOS port would go down, as this is what I predict because the programming in SCUMMVM is probably more efficient.

To the other guy,

I am trying out the HX DOS extender right now...

fingolfin · Post by **fingolfin** » Sat May 28, 2011 4:32 pm

The requirements would go way up for most games. Or code is not at all trying to be "more efficient", to the contrary: Original engines often sacrificed portability in order to squeeze the last drip of performance out of the underlying hardware. Weird tricks and hacks were employed to save a few bytes of RAM here and a few CPU cycles there. We don't bother to do that, which often results in cleaner, and most importantly, more portable code. But the system requirements go way up.

K00L-A1D · Post by **K00L-A1D** » Sat May 28, 2011 4:45 pm

Are you sure the requirements would go way up. I do not think that some games were programmed all that well originally especially in DOS where it seems doing work around tricks to were the norm to get around a bad Operating System which in the long run probably make the requirements go UP. I would like to test this. I bet you for games like SQ4, it would go way down. What do you think about that?

md5 · Post by **md5** » Sat May 28, 2011 9:02 pm

K00L-A1D wrote:Are you sure the requirements would go way up. I do not think that some games were programmed all that well originally especially in DOS where it seems doing work around tricks to were the norm to get around a bad Operating System which in the long run probably make the requirements go UP. I would like to test this. I bet you for games like SQ4, it would go way down. What do you think about that?

I'm sorry I'm not sure I follow your logic here. SQ4 had a lot of so-called "timer bugs", where it calculated game delays incorrectly, with the assumption that the underlying hardware wasn't fast enough. Nowadays, the hardware is way faster than what was available during that era, so the game goes insanely fast on modern computers. This leads to issues like actors teleporting instantly and kill you (like the sequel police in SQ4), or the game not waiting at all for certain puzzles. These bugs are fixed in ScummVM.

However as fingolfin said, hardware requirements go UP in ScummVM compared to the original interpreter, as we have to support a large range of different game interpreters and versions, as well as a large number of platforms, leading into more complex code than the original.

Stryfe · Post by **Stryfe** » Mon Aug 08, 2011 4:58 pm

I installed FreeDOS on a 2005 PC, so it had more recent hardware than the machines DOS originally ran on. Per E-Male's link, I installed the HX DOS Extender.

After running the command from the following site to start ScummVM, it seemed to be working fine, minus some mouse issues. But to be honest, those were more likely than not DOS hardware related.

http://www.unet.univie.ac.at/~a0503736/ ... lists#toc4

md5 · Post by **md5** » Mon Aug 08, 2011 7:27 pm

Stryfe wrote:I installed FreeDOS on a 2005 PC, so it had more recent hardware than the machines DOS originally ran on. Per E-Male's link, I installed the HX DOS Extender.

After running the command from the following site to start ScummVM, it seemed to be working fine, minus some mouse issues. But to be honest, those were more likely than not DOS hardware related.

http://www.unet.univie.ac.at/~a0503736/ ... lists#toc4

Wow, that's quite impressive indeed! According to what the site says, HX-DOS is able to run certain Windows programs (SDL-based programs like ScummVM included) under DOS! First time I see this

Now, I wonder how well this will work with DOSBox...

Mau1wurf1977 · Post by **Mau1wurf1977** » Tue Aug 09, 2011 12:37 am

Ok so let's say you get ScummVM to run in DOS. You will have the same issue as with running real DOS. No sound.

If your machine has PCIe, where the sound coming from in DOS? PC speaker is all you are getting.

And in this case, just use standard DOS. Through software you can disable the internal CPU Cache and you can also reduce the FSB and multiplier of your CPU. It will be very very slow...

This way modern DOS games run just fine on a modern Phenom II or i7. This is something I have tested and it works

NovaCoder · Post by **NovaCoder** » Thu Aug 11, 2011 6:34 am

It's quite easy to see how much of an overhead ScummVM is vs the original interpreter.

For example, go and grab an Amiga copy of say Monkey Island 2 and play it on an Amiga, then run ScummVM and play the same game on the same machine

BTW, I haven't tried this myself yet but I've been meaning to have a look.

K00L-A1D · Post by **K00L-A1D** » Sat May 19, 2012 5:35 pm

I believe there should be LESS overhead, because the games were made when it was easier to do things like video and audio. Can anyone find a game that has LESS overhead than its original interpreter.

Freddo · Post by **Freddo** » Sat May 19, 2012 6:15 pm

K00L-A1D wrote:I believe there should be LESS overhead

Then your belief is false, and fingolfin already explained why earlier in this thread.

dr.zeissler · Post by **dr.zeissler** » Sun Jul 28, 2019 1:57 pm

Interesting old toppic here

I am using a Pentium200mmx with Win95b DX5 and I got some early ScummVM 0.60 installed.
Some things that I found out:

1. sdl.dll: It's better to stick to an older one, even if there is another/newer one included in the scummvm package.
The Mouse slows down dramatically if I use the newer ones, if the is a "lot" of movement in the screen and you move the mouse, all animation freezes.
2. The old ports do support tv2x with all scanlines to be 100% perfect with no pattern.
3. I must admit that games like "sky" are to slow on my p200mmx. I did not find a dos-port that is perhaps faster then the win95version.

Any suggestions what machine do I need if would like to get a smooth gameplay on the old-titles?
Does it make a difference if I choose win98se/dx61 instead?

Greetings
Doc

SCUMMVM port for DOS

SCUMMVM port for DOS

Overhead

Re: Overhead

Re: SCUMMVM port for DOS