Re: Procep SECAM Re: C16/Plus4

From: Anders Carlsson <>
Date: Wed, 2 Nov 2011 14:25:13 +0100
Message-ID: <0BD5B9DFC78C4B6FBE104E9F11FEB66D@ryds>
Richard Atkinson wrote:

> One of the luminance outputs of the GTIA had to be removed in order to 
> free up pins for the VCO interface, so the SECAM Atari 800/XL/XE only has 
> eight luminance levels (128 colours) rather than the sixteen (256 colours) 
> of the NTSC and PAL GTIAs.

Although out of scope for cbm-hackers, does this in some way relate to the 
SECAM version of the TIA used in the Atari 2600? While the NTSC and PAL 
versions output a bit over 100 colours each (the exact numbers vary and I 
can't be bothered to look them up), the SECAM Atari 2600 only outputs the 
eight base colours black, white, red, green, blue, cyan, magenta, yellow. I 
never tried to figure out /why/ that is, but your very detailed explanation 
of SECAM and removed luminance on the GTIA sounds like something similar but 
yet more extreme had to be done with the 2600.

Best regards

Anders Carlsson

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Received on 2011-11-02 14:00:27

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