MS-DOS version correct speed
1 year ago
Île-de-France, France

Hi there,

While speedrunning the MS-DOS version, and even if I always played this game mute when I was young, I was a bit worried that the fact there wasn't any sound effect during the whole run would make it boring to watch.

So I investigated into the game files and found out that I could activate the sound effects by running the install utility and select soundblaster. But I was quite surprise to notice that the game runs now faster than before! This can be noticed in the starting menu, where the music is played faster.

I tried to switch back to normal, but whatever sound card I select for sound effects (even none), the game still runs faster, while my DOSBox conf didn't change.

Here's what I have in my CPU section: core=auto cputype=auto cycles=fixed 20000 cycleup=10 cycledown=20

I use this for Prince of Persia, but I could set a new FB-only conf if necessary.

So I have two questions: 1 - do you think my game runs at the right speed in my current PB (which I posted in another topic of this forum)? 2 - and if so, do you have an idea about why it runs faster now and what option I should use in order to correct this?

EDIT: so, I checked with the 25th anniversary edition, and indeed the game is running faster than normal. I tried a few changes on the CPU options, no luck.

So I thought that since the changes came from the sound card, it should be related to that. Luckily I saved my old fb folder before launching installer, and I could see the differences in FB.CFG: Previous config: BLASTER = A220 I5 D1 New config: BLASTER = A220 I7 D1

Switching back to I5 slowed down the game to normal speed but also removed the sound effects.

In DOSBox.conf, I have this: [sblaster] sbtype=sb16 sbbase=220 irq=7 dma=1 hdma=5 sbmixer=true oplmode=auto oplemu=default oplrate=44100

Switching irq to 5 sped up the game again while putting back the sound effects. So I reached an impasse there. Do anyone have any idea about how to get sound effects with the right speed?

Edited by the author 1 year ago
United States

Try exiting the game (not DOSBox) and run FB.COM again. I have that too, where the speed is wrong the first time (like it doesn't throttle down from 70Hz to 60Hz). It might be a random timing bug, but it usually works on the first restart. In my config, I have the exec set up like this to make the game automatically restart when you exit:

:run goto :run

Île-de-France, France

I don't have a file. Maybe I need to run the installer to create this? I start the game by running FB.exe.

In any case, exiting the game and starting it again doesn't correct the speed, sadly. I'm starting to think this is the right speed and the one we get when soundblaster isn't correctly set is unintentionally slow (maybe because some routine is constantly looking for the sound card).

United States

Oh, FB.COM is the crack launcher, but running FB.EXE should work just the same. Don't worry about that.

I retested, and it seems like you'd need to use the modified exec with the goto call. Somehow the quick action tricks the game into adjusting the speed correctly. Basically, the game is supposed to run at 50fps naturally, but it inits to 60fps based on... something? Very unclear.

I want to look deeper into this, but sadly I don't think it will happen anytime soon. Apologies if you can't get this to work. I'll let you know if I discover any other workarounds in the meantime.

VelCheran likes this
Île-de-France, France

I tried to create an EXEC file containing exactly what you wrote (except for the COM replaced by EXE), but it doesn't work: when I run it, it just waits and doesn't do anything.

United States

You probably don't need a loop. Just modify your DOSBox config to run FB.EXE twice in a row. I feel if it's going to work, it should do so after one restart only. There may be other factors contributing though, so I can't say definitively.

You can send me your config file if you want me to check it out. Also, I didn't ask before, what DOSBox version are you using? Not sure if it matters much, but I could do some testing based on that.

VelCheran likes this
Île-de-France, France

You're a genius, thanks a lot! I added FB twice at the end of my conf file, and the restart sets up the right speed. Awesome :)

TascoDLX likes this