Re: [hatari-devel] A few demos with issues in 1.6.2

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On 23/07/2012 11:49, Anders Eriksson wrote:
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2. Digital World 3 / ICE
http://files.dhs.nu/files_demo/ice_kool.zip

a) some graphics garbage around lower border (second part)


Hello

problem because in the bottom part the demo changes video address in $ff8209 while the display is active. Hatari doesn't fully emulates this so far (on a real STE, it's a bad practice too, but in that case it "works" because the change happens when all pixels are black).



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3. Phantom / Arkham
http://www.atarimania.com/demo-atari-st-phantom_22143.html

a) endpart, screens jumps up/down.

The timings to remove top border are really tight, the switch to 60/50Hz sometimes happens 4-8 cycles to late. This might be a problem in Hatari related to some exceptions timings, but I don't know where. Note that the problem is less visible in STE mode, because on STE top border removal limit is 4 cycles later than on STF.

I think this demo might have been coded on STE and never tested on STF : during the kind of "sine ribbon" part, you get some kind of blue colors in STF mode, and a "better" shade of purple in STE mode. I think the palette was designed for STE with 12 bits and they didn't notice it gave bad results with 9 bits in STF mode :)

So, no easy fix for these 2 for now, they go on the todo list.

Nicolas



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