Atari ST demo without using pixel graphics, entirely made from background colour raster splits. Released at Sommarhack 2024 Zero Bitplane Compo. Demozoo: demozoo.org/productions/352740/
Nearly Incredible !! Amazing 68000 and st mastery / coding skills here !!! I still can guess how many of these effects can be without bit planes / bitmap with such a precision ! It must be a very intelligent construct of tricks and optim. done in several stages of coding before assembly. Huge work & mastery !!! Nice looking fx with many new school like. Music and gfx with that tech constraints rocks !! Respects.
OK, well done - that’s the first jaw-drop moment I’ve seen on the Atari ST since all four borders were opened with a 4096-colour fullscreen back in … 1990? Was it Sync, or Level16? I forget now, but I do know that a full-blown 100% rasters-only demo is something to write home about.
Looks rather VCS-like, which is probably somewhat expected given that you are "racing the beam" for graphics here, though in an even more extreme fashion than tended to be done on the 2600.
Btw maybe a trick to try is to use instead of a few colors repeately after each other at the screen and let the 68000 change after each other. That might even make a higher res possible? For instance in screen memory etc and let the 68000 alter the 4 colors. (And it has been a long time coding the Atari ST mostly in GFA Basic with some assembly. So when I say color 0 color 1 color 2 color 3 I mean the first 4 colors in the hardware registers. ) P.S. How many 68000 clock cycles do you have for 8 pixels? Pretty impressive timing calculations
Not for this competition, there were no pixels allowed. Only background colour. The tech you talk of is used in other demos where it combines bitplane data and rapid colour switches. For example our demo from 2020: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-lm7D8gmEKJI.html (spider screen, tunnel and rotozoom)
It's smashing the background colour a bit yes. But no the black lines are not to save CPU. Just a lame coder doing a black line instead of special case loop (taken dbra is 4 cycles less blabla).
A single register move to the colour register is 8 cycles, and when timing it's one cycle per pixel. There is also the ability to use a 12 cycle instruction to shift everything by 4 pixels.
