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A comment on Secret Colours of the Commodore 64. Parent comment

Re:Secret Colours of the Commodore 64 by OnlyMortal on Sunday March 12, 2023 @06:49AM (#35118618)
Top and bottom border sprites were trivial. A single poke turned off those borders.

Side border sprites were trickier as you had to catch the raster and, to prevent flickering, time your code with a few “nop” instructions.

Then there’s the full screen scrolling trick. Not the 8 pixel shift. I mean full screen scrolling. It used a “bug” in the VIC.

Mayhem In Monsterland been an actual real world use: https://youtu.be/ldo2ewLBt3Y

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Re:Secret Colours of the Commodore 64 by pwrrr on Sunday March 12, 2023 @07:28AM (#35118889)
Yeah VSP. Although you could scroll the entire screen with $d016 by splitting up the fullscreen byte shift in the 7 frames before the shift :)
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Re:Secret Colours of the Commodore 64 by prvc on Sunday March 12, 2023 @09:19AM (#35119728)
Doesn't it support scrolling officially?
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Re:Secret Colours of the Commodore 64 by tinus_hn on Sunday March 12, 2023 @09:56AM (#35120060)
It supports scrolling up to 7 pixels but after that you have to actually move the memory backing the screen, and the cpu is slow enough that it’s pretty hard to do.
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