Re: Bouncing an idea here...

[rubywand@aol.com (RUBYWAND)]

In article <4aiv94$3g3@bcfreenet.seflin.lib.fl.us>,
z008729b@bcfreenet.seflin.lib.fl.us (Martin Gruen) writes:

>
>  I was thinking about the 3200 graphics mode and how it was accomplished

    3200 colors in 320 mode comes from being able to select one of 16
palettes for each of the 200 scanlines. For games that handle different
stuff in different parts of the screen-- like an adventure which shows
sky/roof in the upper 10%, char status in the lower 20%, 
buildings/maze/monsters in the middle 50%, etc.-- using extra palettes can
make the display more attractive and interesting. 
 

>  Has anyone attempted an equivalent using the 640x200 resolution?  Can 
>it be forced to take more colors, or to have different pallets per line? 

>Is that 1200 colors?
>

   In 640 mode, each dot can have one of 4 colors. It possible to have 16
colors on a line; but, these are distributed over dots in groups of 4. If
you want to be able to move 
a 640-mode sprite (like a monster figure) smoothly at true 640 resolution,
you are stuck with 4 colors/line. 4 x 200 = 800 colors in 640 mode.

   Each of the 200 Scanline Control Bytes let you select a Palette and the
Resolution for the line. So, a game might use 640 mode for the lower 20%
devoted to text I/O and 320 mode for the rest of the screen.

   You are allowed 1 interrupt per line, which might be used to set the
palette for the next line, adjust a sprite, etc.. You are not allowed to
change palettes in mid-line.

  
>  One more thing, are there any games that have been created using 3200? 

>I usually only see graphics viewers/paint programs and demos.
>

   A few games have used multiple palettes in a limited way (e.g. to show
an impressive title screen).  So far, there is no full-featured Painter
utility which allows creating pics with multiple palettes.