[hatari-devel] Another SYNC demo, another one not emulated ... :)

[Troed Sångberg <troed@xxxxxxxxxxx>]

(but this time it's not something I've found - we're just making use of czietz' discovery of desyncing GLUE and Shifter videomodes)

https://demozoo.org/productions/325847/

It's using the GLUE-color/Shifter-mono option which is compatible with both ST and STE. With scanlines 512 cycles long the Shifter manages to output 1280 pixels per line, giving rise to the interesting resolution of 1280x200 pixels.

(Each line still 160 bytes, as usual in color modes)

This is "easy" to use on real hw, if you have one of the ubeswitch (STVGA) adapters where you can toggle between color or mono pin being output to the screen.

The whole trick relies on the Shifter not knowing anything about UDS/LDS, and thus it's possible to set one videomode in GLUE/Shifter with a regular ffff8260 call, followed by one setting the videomode in Shifter only by another call to ffff8261.

czietz original post: https://www.atari-forum.com/viewtopic.php?t=34108

(The opposite trick, GLUE in high res and Shifter in color, only works on ST since on STE it will give rise to BLANK being constantly on)

regards,

Troed