[Coco] Re: Re: CoCo Monitor

[Rodney V Hamilton]

In article <40DB8CB1.7010901 at worldnet.att.net>, 
robert.gault at worldnet.att.net says...
>
>Actually that was not a good example. What I should have said was:
>run
>10 PMODE3,1:PCLS2
>20 PMODE4,1:SCREEN1,1
>30 GOTO30
>
>In a PMODE3 screen, PCLS2 will fill the screen automatically with every 
>other vertical line. Then changing the mode to PMODE4 on an RGB monitor 
>would show alternating black and white vertical lines but on a composite 
>monitor will show either all red or all blue artifact color.

You can get BASIC to do the colors for you automatically by drawing
in PMODE3 on a PMODE4 screen, like this:

10 PMODE4:PCLS:SCREEN1,1:PMODE3
20 COLOR RND(4)
30 LINE-(RND(255),RND(190)),PSET
40 GOTO20

You can also get interesting effects by adding ",B" or ",BF" to the
end of the LINE command.  I called the ,B version "Night Gallery"
since it reminded me of the gfx bit in Rod Serling's TV show...

For fun, here;s an old 1-liner I did to do overlapping circles.

6 IFT THEN6ELSEPMODE4:PCLS0:SCRE
EN1,1:PMODE3:E=.88:FORT=0TO99:X=
RND(252)+1:Y=RND(190):R=RND(25)+
7:C=RND(3)+1:FORI=3TO5:CIRCLE(X,
Y),R,I,E:PAINT(X,Y),I,I:NEXTI:CI
RCLE(X,Y),R,C,E:PAINT(X,Y),C,C:C
IRCLE(X,Y),R,I,E:NEXTT:GOTO6