Pushing additional lines into the playfield register.

[Joel D. Park]

I was just curious,

 

According to the info I've read, and now the new Tutorial that is being created by Kirk Israel, though the width of the playfield must be 20 pixels (Times 2, either Mirrored or Copied), it sounds like you can make the height as high as you want.

 

Does this just happen automatically, For Instance. Right now the screens in adventure are only 7 pixels tall, if I were to shove say 3 more pixels into the register, would it automatically adjust the screen and have some additional detail?

 

Is that how the high-res backgrounds for Activision games are done? Or do they use un-documented magic.

[Thomas Jentzsch]

Does this just happen automatically,   For Instance.   Right now the screens in adventure are only 7 pixels tall,  if I were to shove say 3 more pixels into the register,  would it automatically adjust the screen and have some additional detail?

Actually the screens are only 6 blocks tall (the upper and lower blocks are only half as high)

 

If you increase the number by 3, then the whole vertical screen size would be increased too. The game wouldn't display 262 total lines anymore, but 3 times the height of the vertical playfield-blocks more. This would cause the game to run with less than 60 Hz frame rate and the screen might not be completely displayed anymore.

 

Small differences are not a problem, but if you go to far, your TV might have problems to sync.

 

To overcome this problem, you have to reduce the height of the vertical blocks, so that the total number will stay close to 262 lines.

 

The vertical resolution of all graphics depend on the programmers skill. If you change the contents of the (e.g. PF-) registers every line, then you get that higher resolution (like the trees in Pitfall, the ark in Cosmic Ark or the cave lines in Thrust).

[Joel D. Park]

Thanks,

 

That doesn't sound like something I'm ready to worry about yet. :-)