Re: [stella] What's an acceptable scanline count? (NTSC)

Subject: Re: [stella] What's an acceptable scanline count? (NTSC)
From: Thomas Jentzsch <tjentzsch@xxxxxx>
Date: Mon, 14 Jul 2003 23:05:45 +0200
Zach wrote:
> After reviewing the replies to my question, I believe that 280 is a safe upper-bound. (Wall
> Ball is also 280.)

Yes, but IIRC soem people have had problems with those games. I would
stay a bit below if possible.

> So if I were to do, say, a reduced scanline version of Air Raid, do
> you have any tips on how to proceed?

Disassemble it and look for the writes to TIM64T. There should be two,
one for the upper and one for the lower part outside the display
kernel. Reduce both values until you get the desired scanlines. Then
check if the game still produces a constant scanline line number.

If you are having problems, use the trace function of z26.

It's normally quite easy. Only games that need all the extra CPU time
are tough.

Have fun!
Thomas Jentzsch         | *** Every bit is sacred ! ***
tjentzsch at web dot de |

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