[Coco] Re: CoCo Monitor

KnudsenMJ at aol.com KnudsenMJ at aol.com
Thu Jun 24 22:28:22 EDT 2004

In a message dated 6/24/04 7:08:33 PM Eastern Daylight Time, 
robert.gault at worldnet.att.net writes:

> Take your Coco2 and in PMODE3,1:SCREEN1,1 draw vertical lines at every 
>  other horizontal position. Now issue a PMODE4,1 command without a 
>  SCREEN. You should see either a full red or blue screen.
>  By choosing various horizontal dot patterns, it is possible to get on a 
>  PMODE4 screen, white, black, red, blue, yellow, green, and several other 
>  colors.

Even better -- write a short BASIC program using the RAND function to draw 
vertical lines at random horizontal positions.  Alternate between white and 
black lines, so as the lines build up on the screen, there will always be an 
average of 128 out of 256 possible white lines.

You will see an ever-changing "aurora" palette of colors you never saw on a 
Coco before, smeared across the screen.  Just leave it running for several 
minutes, or hours, as background wallpaper.  Tell ignorant visitors it's the 
latest and greatest PC screen saver :-)

This is how I discovered artifact colors by accident, way back in 1983 or 
--Mike K.

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