[Coco] Will the *real* artifact colors please stand up?

[John Kowalski]

I was playing Sea Quest on Brad Grier's excellent Mocha emulator the other
day and noticed that the grass in the adventure was showing up as purple
instead of green (using complex artifacting).

Naturally, I assumed I made a mistake in the complex artifacting algorythm
and asked Brad to swap the green and purple colors - and he did.

Then I pulled out a *real* CoCo 1 and tried playing the same game...  And
the grass showed up as purple instead of green!   What the...!!??

I then tried other PMODE4 games that used complex artifacting and things
like grass did show up as green!

...Which leads me to my question...  Are the rarely used artifact green and
purple colors the same on all CoCo 1s?   Do the patterns that show up as
green and purple on one CoCo end up showing as other colors on other CoCos?


Could anyone who has a CoCo 1 please type in this short program and write
back what colors you see:

10 PMODE4,1:PCLS:SCREEN1,1:PMODE3,1:A=2:B=2.5
20 FORY=48TO143:FORX=(Y AND1)+65TO191STEP4
30 COLORA:PSET(X,Y):COLORB:PSET(X+2,Y):NEXT
40 A=A+1/48:B=B+1/48:IFA>3.5THENA=1
50 NEXT
60 GOTO60

On my CoCo 1 the program displays 4 bars of color - red,green,blue and
purple  (or blue,purple,red and green depending on the CoCo's mood.)

Please write back and tell me which four colors you see on your CoCo, and
what model CoCo you're using.

(Don't bother with a CoCo 3 - the green and purple bars will likely just
show up as grey and grey.)

                                         John Kowalski (Sock Master)
                                         http://www.axess.com/twilight/sock/