Refresh rate differencies among versions of a same game

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Mr_Nutz
Posts: 32
Joined: Sat Jun 23, 2007 7:14 pm

Refresh rate differencies among versions of a same game

Post by Mr_Nutz »

Hello there

I've this doubt now that I can run Scummvm with vsync on, thanks to the OpenGL scaler :)
For example: DOS versions of Scumm games ran on 70HZ video modes (320x200@70HZ I guess), while MAC versions usually ran on more advanced display modes, like 640x480@60HZ.
Is that right for Scummvm also? Do MAC games refresh internally at 60HZ as opposed to the DOS versions? (NOTE I'm talking about internal refresh rates: I know the games don't actually redraw 60 times per second, but they relay on a fixed frequence on their original platforms, that's for sure!)

What about the AMIGA versions? Do they expect 50HZ modes?
(Again, I'm talking about "internal" timming the game is based, not the actual screen redraw speed wich was non-constant in every scumm/gob game I ever played, except maybe for the Ween's scrolling intro, wich I only got to play smooth in a VESAFB that replicates a DOS mode 320x200@85HZ, btw).

regards
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bobdevis
Posts: 567
Joined: Fri Jan 16, 2009 10:52 am

Post by bobdevis »

Are you actually having a problem?

If you do, then you probably should explain better what it is.
If not, then there is nothing to worry about.

Basically all the modern video card hardware/drivers figure out what to do on their own given any monitor frequency and application redraw rate.
Mr_Nutz
Posts: 32
Joined: Sat Jun 23, 2007 7:14 pm

Post by Mr_Nutz »

I'm not having a problem. It's a technical question.
I appreciate your interest in helping me, but that's not the kind of answer I need.
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eriktorbjorn
ScummVM Developer
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Joined: Mon Oct 31, 2005 7:39 am

Post by eriktorbjorn »

I don't know if this is an answer either, but as far as I know nothing in ScummVM knows or cares about the actual screen refresh rate.
Last edited by eriktorbjorn on Mon Feb 14, 2011 9:24 am, edited 1 time in total.
fingolfin
Retired
Posts: 1452
Joined: Wed Sep 21, 2005 4:12 pm

Post by fingolfin »

SCUMM internally measures time in "jiffies", which is 1/60th of a second. Take a look at ScummEngine::go in scumm/scumm.cpp. Then, the game script's can control via some variables how fast the main loop runs.
I am not aware of any differences for that in the Amiga version.
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