Why screen size varies across games?

[pkupcik]

Can anyone enlighten me why some Amiga games are displayed in full screen, some games take up about 3/4 of the screen and some games some other weird portion of the screen? Is it to accelerate games when they use less of the screen? I've also noticed that AGA games are more likely to run full screen than not. Why? Is there a way to force games to use full screen?

[pkupcik]

I have PAL A1200 and tried using it with composite output on PAL TV or RGB PAL to VGA NTSC converter on computer monitor - both with the same result. Most of the games are too short, e.g. Lotus, Lemings, Street Fighter, Chuckie Egg, Test Drive, etc. Some seem to be just a little bit short, say 1/5 of a screen which would probably explain the PAL vs NTSC optimization, but some are way short, like 1/3 of the screen, eg. Lotus 2. Most of the AGA games I have seem to be either full screen or just 1/5 too short.

[pkupcik]

I looked at Lotus 2 again and it looks like the screen is only about 1/5 short which would be the missing pixels from 256 PAL resolution compared to 200 in NTSC. And because the game has extra black border around the whole screen, the bottom gap looks extra tall (when you add both gaps together) - I guess I was visually tricked thinking the gap is larger than that.

[pkupcik]

so you are using a pal amiga, what are the games? are they pal or ntsc? I think overscan is more likely a reason for the varying size of screens. Overscan uses more memory so many games dont use it.

I have only ever had ntsc amigas and games and the screens on many were different.

Yes I'm using PAL A1200 and I'm in USA, but I do also own PAL/NTSC TV. The games I tried I believe are PAL, e.g. Lotus 2, 3, Lemmings, Indiana Jones, etc.

I just did another test though with Lotus 2. I booted Amiga in NTSC mode by holding the mouse buttons on reboot and when I played Lotus 2 the screen was nicely stretched all the way to the bottom. I guess I will need to try playing games in NTSC mode to have the picture stretched across the full screen. Does anyone know how to force NTSC boot by default?

[pkupcik]

Now I've read somewhere that there's a way to configure WHDLoad to force either PAL or NTSC for each game. Does anyone know how to do that? That would be great if I could pre-configure that on game by game basis.

[pkupcik]

OK, I figured it out, I can use TOOLTYPE to configure each game to use PAL or NTSC, that way I configure each game individually depending on whether it looks and works better in PAL vs. NTSC.