Draw on screen border in Commodore 64
- by Stefano Borini
Ok. I hope it does not get closed because I have this curiosity since 25 years and I would love to understand the trick.
In the commodore 64 the border was not addressable by the 6569 VIC. All you could do was to draw pixels in the central area, the one where the cursor moved. The border was always uniform, although you could change its color with poke 53280,color if i remember correctly.
Nevertheless I clearly remember games intros where the border was featured with graphics, like it was fully addressable. I tried to understand how it worked but never got to the point. legends say it was a clever use of sprites, which could, under some circumstances, be drawn on the border, but I don't know if it's an urban legend.
edit: just read this from one of the provided links
Sprites were multiplexed across
vertical raster lines (over 8 sprites,
sometimes up to 120 sprites). Until
the Group Crest released Krestage 3 in
May 2007 there was the common
perception that no more than 8 sprites
could appear at one raster line, but
assigning new Y coordinates made it
reappear further down the screen.
This is evil.... you beat the raster and reposition the sprite before it gets there...
