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

[jdaggett at gate.net]

MIke

Actually it does make sense. The GIME chip can be set to keep 
fixed the upper 512 bytes of the memory map as 256  bytes of ram 
and 256 bytes of I/O. It is t his 256 bytes of ram that is imporatant. 
SInce 320x192x8 requires 61,440 bytes of ram for video the 
program that uses 256 colors would have to switch banks of ram to 
write to the video ram. 

The GIME can utilize two separate task running. One for video ram 
writes and the other for the program. The common bond of memory 
between the two tasks is located in the 256 bytes of ram located at 
$FE00 to $FEFF. 

james

On 10 Aug 2005 at 9:35, Mike Pepe wrote:

To:             	ColorComputer at yahoogroups.com
From:           	Mike Pepe <lamune at doki-doki.net>
Date sent:      	Wed, 10 Aug 2005 09:35:49 -0400
Subject:        	Re: [Color Computer] Re: [Coco] Hidden 256-
color mode
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> The way you're supposed to enter this mode also makes no sense to me.
> Unless the designers intended this feature to never be discovered,
> there's no reason to make it so complicated. It may be some clever
> state machine hack, but again it seems illogical to make this mode's
> selection such a bizarre hack.