I didn't watch the movie (or looked at other posts) but I know this problem extremely well, the reason for this is, that the SP fix doesn't like DOSBox's screen drawing.
To solve it, just use the original executable and not spfix63.exe - if you are unable to acquire one, don't worry, just use spfix63 but set the speed reducing factor to zero. In order to do that, just hit the + key several times (the one that's on the Numpad - to the right of the keyboard) during a level, OR, start the game with the command line parameter for factor 0 slowdown (IIRC the command is: "spfix63.exe * 0" but read the spfix documentation to be sure).

After you've set the slowdown factor to zero, just use DOSBox's cycles to increase or decrease speed.

HTH,
Og

Og thanks for your quick reply.
I have the original supaplex.exe but I like the spfix63.exe because of its new capabilities (save game, load game etc.).
I tried what you have suggested, but still have trouble.
when reducing the factor to zero, either I get a stuttering screen or a super fast Murphy.

Anything else?

Start it with

spfix63 h

@Matrix:
I didn't really use spfix much before, but now I looked and indeed it's only full speed (which is the speed I play at) or stuttering. Original EXE works fine though.
I didn't even remember that spfix had saving and loading options (long time since I read the documentation) - IMHO that's cheating (something that I don't like to do(unless I finished the game w/o cheating first)).

@h-a-l-9000:
Thanks for the tip, it works well 😀
BTW, after I wrote the earlier post, I searched and found this message, does it mean that using your patch will enable to run spfix63 without t "h" parameter? Because I tried downloading the latest CVS (from AEP) and changing machine to vgaonly but it didn't help 😖 am I doing something wrong or is the mentioned supaplex fix is for something else? (BTW, I'm only asking because I have another game with the same problem (only more serious))

that patch isn't in the cvs yet. That is why it is not in AEP builds.
Which game does have a problem ? Might be another testcase.

Thank you all for your help.
I already tried the H command line option, but then I saw that I applied it with applying a speed factor (*n) 😜
Without a speed factor the H option works great.

Qbix wrote:

that patch isn't in the cvs yet. That is why it is not in AEP builds.
Which game does have a problem ? Might be another testcase.

It is an Israeli kiddie game, if you can direct me to a compiled build with hal's latest changes, I'll be happy to see if it works. See attachment for a recording of the issue.

Maybe on mr. Hal's homepage?

I looked but didn't see it there, unless it's in the "megabuild" but even if it is, the build's date is older than the aforementioned patch.

Yes it's too new 😉

og check your pm