[Color Computer] Re: [Coco] Hidden 256-color mode

James Diffendaffer jdiffendaffer at yahoo.com
Wed Jul 27 15:46:40 EDT 2005

Ok, that was a mess so I'll try again.

16 color registers with added YY value = 32 bits, not 128.
And I said it backwards the first time as well.

--- In ColorComputer at yahoogroups.com, "James Diffendaffer"
<jdiffendaffer at y...> wrote:
> Just a small observation here.  If the display hardware can handle
> intensity why not support YY in the palette registers?
> Hmmmm... was another 128 bits of storage and loading the YY value
> rather than having fixed YY values really that much of a space saver
> on the chip?
> --- In ColorComputer at yahoogroups.com, "James Diffendaffer"
> <jdiffendaffer at y...> wrote:
> > > Since the CoCo 3's palette entry format is really XXRGBRGB then 
> > > YYRGBRGB makes sense, giving a total of 16 colors out of 256 if the
> > > upper two bits are put to use for the intensity.
> > 
> > Excellent point on the palette format but isn't that 64 colors rather
> > than 16  (4 bits = 16 colors, 6 bits = 64)?
> > 
> > It's probably going to have to match the palette data since it's
> > bypassing the palette lookup hardware unless they want to modify the
> > bits.  Changing the order of the lines to go from YYRRGGBB to YYRGBRGB
> > doesn't require gates but it makes sense to directly output data in
> > the same format anyway.

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