Re: [stella] NTSC - PAL porting guide

Subject: Re: [stella] NTSC - PAL porting guide
From: Nick S Bensema <nickb@xxxxxxxxxxxx>
Date: Sat, 8 Mar 1997 15:48:54 -0700 (MST)
>
>
>
>On Sat, 8 Mar 1997, Eckhard Stolberg wrote:
>>    NTSC                 PAL
>> 
>>    grey                 grey
>
>It would be useful to establish actual RGB values for 2600 output instead
>of just names.  I realize that these are the 16 hue values available.  You
>won't be able to establish true RGB values just by grabbing screens
>because the 2600 may be slightly off its center calibration and going from
>RF or composite to RGB results in unpredictable results.
>
>But it could be calculated mathematically.  If you establish that there
>are 16 hues, and 8 luminances per hue, then you should be able to convert
>HSV to RGB to get at the internal values the 2600 is attempting to
>generate.  I could probably do it if noone else wanted to.

Huh?  Uh, WHY?  I'm just interested in which value makes a good yellow,
or a good blue.  There's not much else to it.

The truth about Atari hue-luminance video is that the luminance controls
saturation, not brilliance.  $20 makes a deep red, which could easily
fade to white by incrementing to $2E and shifting to $0E.  But you cannot
fade to black from it.

We must also consider that PAL is a much more delicate format than NTSC.
I never would have dreamed that if the vertical blank time were off, the
color would be out of whack or missing, but apparently it is true.
Also witness the apparent color differences in PAL versions of 
Supercharger games. 



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