Re: [stella] NTSC - PAL porting guide

Subject: Re: [stella] NTSC - PAL porting guide
From: Eckhard_Stolberg@xxxxxxxxxxxxxxxxxxxxx (Eckhard Stolberg)
Date: Mon, 10 Mar 1997 12:39:06 +0100
>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.

It would be nice, if you could do this, because I don't know enough about
colour systems to do it.

>>    orange               gold
>>    orange green         grey
>>    light orange         grey
>
>What seems odd about this is that the 16 hues on the left table do not
>match up with the right table.  There seem to be more hues available in
>NTSC...  For instance, there are no orangy hues in PAL, as these tend to
>come out "grey".
>

All the grey values might actually be a little bit different. That is why I
wanted someone else to confirm this, because I am a little bit red-green blind.

The brighter versions of orangebrown look orange.

>Shouldn't the 2600 be able to generate all the same hues in PAL as it can
>on NTSC?

No, while NTSC uses YIQ as it's colour space, PAL uses YUV. Since the TIA
produces the same coordinates on both TV standarts, they result in different
colours. Because the VCS only has 16 hues, they might not all have a 
corresponding hue in the 16 on the other TV system.


Thanks, Eckhard Stolberg


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