SCUMM: MANIAC: Support for the V1 built in demo.

[robertmegone]

Certain versions of Maniac Mansion(V1) for DOS, came with a built in demo alongside the full game.

It can be seen running here: ​https://www.youtube.com/watch?v=DzgKiGLLCkM&ab_channel=DFXPony

It looks like the demo was started by running a bat file containing 'maniac demo'.

I don't see a way to choose to run this demo in ScummVM, is there any chance that this option could be supported somehow?

[AndywinXp]

I just mapped a partial disassembly of Maniac Mansion v1; it seems that in order to launch the demo it is sufficient to run script 9 instead of the bootscript (script 1).

And I discovered... we were already (kind of) doing that!
...but only if the game is recognized as the demo version:

(from runBootscript())

if (_game.id == GID_MANIAC && (_game.features & GF_DEMO) && (_game.platform != Common::kPlatformC64))
    runScript(9, 0, 0, args);

I think that maybe we could put a checkbox in the game options for it to run on demo/kiosk mode...

[einstein95]

Until it's added as an option to the GUI, what you can do is run ScummVM from the command-line with the --demo-mode option, for example scummvm.exe --demo-mode maniac-v1-dos

[robertmegone]

Very interesting, I noticed that this --demo-mode flag actually seems to work for many of the ports.