Here comes my contribution to the Sommarhack 2022 party in Sweden…
Certainly not the most original screen in the world, but it is the first full overscan scrolling (without syncscroll), packed in less than 256b.
This program respects the general bytetros rules : 224b code + 32b header = 256b executable file !
It finished 7th of the 256-byte intro competition of Sommarhack 2022, out of eight entries; the winner was Shiraz by Marquee Design.
In 224 bytes of code, the program does what the big fullscreens of 1989 did. It opens the top border with a short 60 Hz switch and synchronises with the electron beam by reading the video address counter. Then, on each of the 274 lines, it switches to high resolution to open the left border, to 60 Hz to open the right one, and to high resolution again for a moment to stabilise the line, before opening the bottom border. The picture is filled with noise, made of a value mixed by EOR and ROXL instructions, as in my 32B Noise.
These border switches are explained on the Atari ST Fullscreen demos history page.
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