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

[John Kowalski]

At 11:48 AM 05/07/2004 -0500, CoCoList for Color Computer Enthusiasts wrote:
>Hi,

>

>You partially answered your own question when you said  "...depending on the
>CoCo's mood". You may have noticed that there are quite a few games that
>will have a red or blue box and tell you to press reset until the correct
>color is displayed. It is all a matter of timing. The patterns are the same
>for red and blue or purple and green, it just depends on when the pixels are
>placed on the screen.


That's why I listed both orders of the colors that can appear when I run the
program on my CoCo 1 - red,green,blue,purple or blue,purple,red,green.

But what I mean about the green and purple variants is that even when I
toggle  the correct artifact colors (keep pressing RESET), in certain games
green and purple still appear incorrectly....  In Sea Quest, the sky will be
blue, fire will be red, *BUT* grass will be purple!

In other games programmed by other people, all colors will be correct - even
grass will be green.

Some people's games will consistently have incorrect green & purple on my
CoCo, while others will consistently appear correct.   In the games where
grass appears purple on *my* CoCo, did it appear green on the programmer's
own CoCo?

Do some CoCo 1s display artifacting differently than others?

The simple artifacted red and blue are consistent with *ALL* CoCo models,
but the extended, or complex pattern artifact colors like green and purple
may appear differently on different CoCo 1s.

This is what I want to find out - Are all CoCos equal?  Did the programmer
of Sea Quest (and other adventure games) simply make a mistake and paint
grass purple in his games?


Anyone with a CoCo 1, please type in this program and tell me the 4 colors
you see, and the order in which they appear.

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

Thanks!

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