I thought that was a caching issue? *ponder* That sounds so familiar to me. "Turn caching on for the CD-ROM drive using SMARTDRV." If it plays perfectly under VDMSound...

What happens if you allocate more CPU cycles to DOSBox?

I have tried 3,000..25,000 cycles to no effect. The result is identical.

I don't really see how it could be CD-ROM related since I copied the whole thing to hard drive. Just for good measure, I also attempted to play it from CD, but no effect. Does the same if I copy the whole thing to a 350MB RAM drive.

Agreed, sorry, I was thinking while I typed - the smartdrv suggestion was what I thought the original problem was. 😀 i.e. Sierra's suggested resolution to the problem.

Are your VDMSound and DOSBox SoundBlaster configurations identical? I thought VDMSound defaulted to IRQ 5 while DOSBox defaulted to IRQ 7.

I have no solutions - I'm simply throwing things out there for consideration. 😀

else try an older version of dosbox like 0.61

Actually, he didn't mention what version he was trying in the first place.

Also, have you installed this patch: http://dlh.net/cgi-bin/patdl.cgi?lang=eng&sys … ile=kq6cdhi.zip

That is a patch for the Windows version.

Oops...

That patch is for the Windows version only.

The intro video does play properly with 0.61 (sound is messed up, though). 0.62 and later exhibit the problem I'm experiencing. (I was testing with 0.63 and CVS before).

I'd be glad to go bug-hunting myself, but I have no idea where to look for this type of bug... Does anybody have any suggestions on where to begin or any hints on how to determine what actually happens?

Have your tried all four core types in the latest CVS? (simple, normal, full, dynamic)

Yep. All identical.

If I'd have to make a guess as to what's happening, it'd be the following:
the video decoder decodes several frames of video ahead of playback, storing them in off-screen video memory pages (unlikely, since this would require 64k of video memory per frame and it's decoding at least 5 frames ahead) or in something like EMS pages. When replaying them, something goes wrong in swapping the pages back in, displaying a frame ahead of time. It's very difficult to verify this, though.

I'm thinking about creating some code that allows me to view a graphical representation of memory while debugging, to easily identify bitmaps.

That would be interesting and useful for debugging.

Does the game require EMS in order to run, or can you turn off EMS in DOSBox and force the game to use XMS instead to see if there's a difference?

It does sound like it's decoding several frames of video to video memory, and that somehow the visible frame is being overwritten with a later one before it swaps over the next one that's supposed to be visible.

So much for that theory 😢
Disabling EMS yields no improvement, nor does telling the game's installer "don't use your machine's extra memory".

BTW, HunterZ, I appreciate your thinking along.

Interesting that you get good video results with 0.61, but not with later versions. Could be DOSBox, but it could also be due to different versions of SDL.dll.

Reminds me of a similar problem with Arena. Works fine with 0.61, black screen in later versions.

One thing to try: Set environment variable SDL_VIDEODRIVER=windib before launching DOSBox.

try without sound ? (as the sound was messed up in 0.61 but image was correct)

I tried using DOSBox 0.61's SDL.dll will the new version. No effect. (Although I doubt SDL could actually predict future frames).

Disabling the sound also disables the intro (it switches to displaying text only, no movie). Tried different sound card drivers. Again, no effect.

Does the game have a selection of video drivers/modes that you can choose from?

It only has VGA320x200x256 and a B&W driver (which also doesn't display the intro, replacing it with the text).

I just confirmed this, too. The floppy version's intro is different from the CD's and both exhibit the same behavior. .63 and CVS.

hmm yeah I recall Ierioume talking about it sometime.
Dunno should be something in the beta tester forum. We never figured out what wrong, but as it's non-fatal it doesn't have a high priority either.