G05 “scanline” or tearing effect Atari Asteroids

Aniraf

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Is it normal for the Asteroids output to emit Asteroids which have a tear/scanline accross them as they pass certain areas of the screen? I wish I could get a picture of this, but essentially imagine the outline of an asteroid having an invisible horizontal line cutting through it and giving the effect of some offset pixels on either side of the asteroid.

I used the description of "scanline" because it would appear that this line is very slowly climbing up the screen. From what I understand, vector monitors would never have the equivalent of a scanline because of the way the image is drawn.
 
Are you seeing a connecting line being drawn very faintly connecting every object on the screen? If so you may have brightness or contrast up too high, turning those down will hide that line. Though this may not really be your problem, but it's an easy thing to try.
 
Issues in your analog section, or maybe late in the digital section. A bad DAC will do it, or one of the counters feeding it. You'll need a board repair.
 
Are you seeing a connecting line being drawn very faintly connecting every object on the screen? If so you may have brightness or contrast up too high, turning those down will hide that line. Though this may not really be your problem, but it's an easy thing to try.

It's not the brightness thing, I know that one. I wish I could snap a picture of this :/. Imagine if you were to draw an asteroid on paper, then cut the picture in half. You would then lay it back together about one millimeter shifted from perfect.
 
Issues in your analog section, or maybe late in the digital section. A bad DAC will do it, or one of the counters feeding it. You'll need a board repair.

Oh ok. I can totally do that if I know which part to replace. Are you talking about the "crystal" when you refer to the counter?
 
Oh ok. I can totally do that if I know which part to replace. Are you talking about the "crystal" when you refer to the counter?

LS191 TTL ... use logic probe to figure out which one ... there are many to chose from ... LOL
 
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