| Posted By
Dunric
on 2004-04-16
19:40:51
|  PAL vs. NTSC question?
I have a few misc. Plus/4 games, some that are PAL. These don't run at all on my NTSC Plus/4 (the screen just scrolls endlessly when I type RUN). Do I need to patch my NTSC Plus/4 unit through a VCR or something to my Commodore 1084S monitor? That was how I was able to play Atari 2600 PAL games on my NTSC monitor previously.
Any ideas?
Sincerely,
Paul Allen Panks
dunric@yahoo.com
Phoenix, AZ USA
P.S. I'm thinking of converting several more of my C64/128 adventure games over to the Plus/4. However, I am having difficulty emulating sprites. Can I save a sprite on the C-128 in bitmap format, i.e. via SPRSAV, and then LOAD it on the Plus/4?
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Posted By
Crown
on 2004-04-17
09:22:37
| Re: PAL vs. NTSC question?
Based on the symptom (rolling screen), I would say that these games are using some advanced raster tricks to open up to border, this involves writing some line numbers into the raster line counter where the meaning of the value is different on PAL and NTSC due to the different screen height. This can result in a broken picture where the vsync sygnal is very very late and in these cases the monitor starts to wrap the picture and roll it...
If this is done by an intro before the game, then you could just press SPACE skipping it and hope that the game behaves better.
Otherwise the software would need to be patched for NTSC (if possible at all), or a real PAL machine has to be used.
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Posted By
TLC
on 2004-12-22
07:17:59
| Re: PAL vs. NTSC question?
Yep, and there's something more to consider... It's been a common programming practice to write TED registers directly (I mean, you'd use LDA #$18 / STA $FF07 to turn multicolor mode on, instead of the more correct form of LDA $FF07 / ORA #$10 / STA $FF07). Nobody argued about that, since everyone have been using PAL Plus/4's. If someone such these programs on an NTSC machine, he'd have noticed that they switch the NTSC machine to PAL mode. ...No, you won't get a standard PAL picture on the screen, since the crystals needed for the two modes are different; you'd get a "slow", nonstandard videosignal instead, with which no displays are compatible.
So, I suggest something like this: the sw you tried turns the NTSC machine to PAL mode accidentally. If it's a serious problem (not just skipping an intro or so), then it'd need some patching to work with NTSC machines. You'd have to patch (at least) the $ff07 accesses in the code.
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