Recycling a Message by _Marc Melvin@1:110/1065.0_ to
_All_ (Date: 09.07.97)
MM> though I have to use this 30 line code to just draw a pixel... well, I
MM> would appreciate it if someone could help me out here... assigning
MM> $A000:0000 to 255 doesn't work with 640x480... yipes... :)
The problem is that mode 12h (640x480x16) uses planes. The VGA-RAM is  
divided into 4 Planes, each containig 1 Bit of all pixels. When the DAC  
has to write the pixel onto the screen it reads out all 4 planes to get  
the 4 bit color-number.
When you want to write a pixel you have to switch planes and write each  
single Bit of the color! So putting a pixel in 640x480 is a rather slow  
procedure :-( and the 30 line code you use appears to be a good  
approach...
To speed things up you can use a virtual screen and write a whole bitplane  
before swithing to the next plane.
MM> --- TriToss (tm) Professional 11.0 - #229
CU,                  Fido: 2:316/5.9
   Stephan         e-Mail: weini@sbox.tu-graz.ac.at
                      WWW: http://www.sbox.tu-graz.ac.at/home/weini
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