[hatari-devel] Hatari 1.4 emulation bugs

Anders Eriksson ae at dhs.nu
Fri Nov 5 14:01:27 CET 2010


Hi,

while doing some testing, I found some bugs in Hatari 1.4 emulation for 
some demos (I'm sure there are more, but these are the ones I've seen so 
far).

All tested on Mac OS X 1.6 with Hatari 1.4. I'm aware that Monsieur Styckx 
have made some fixes regarding STe overscan since v1.4, but I've not been 
able to test that yet, so maybe the errors for More Or Less Zero described 
below are already fixed.

Anyway, here's the list:

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1.
Wave of the future / ICE
http://files.dhs.nu/files_demo/wavefut.zip

a) Top border flickers
b) Sound crackles a bit

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2.
More Or Less Zero / DHS
http://files.dhs.nu/demos/molz_hdd.zip

a) Fullscreens are shifted too much to the right (8px approx) - also seen in Cernit Trandafir and Tuttugandi (the 20 years STe megademo screen by DHS)
b) When using hardware scroller in fullscreen, there is graphic garbage in the right border (Firehorn pic and interference circles), also seen in Tuttugandi
c) Music and effects get unsynchronised after the plasma. In Hatari the sample loop that plays during the end of the plasma repeats four times, but on a real STe it repeats three times. The counter is on VBL and the soundchip is 25033 Hz. As far as I can tell either the VBL or soundchip frequency (or both) runs a little bit wrong speed (see video links below)

Videos to illustrate the audio sync problem

Real STe: http://ae.dhs.nu/tmp/molz_stesync.mp4
Hatari 1.4: http://ae.dhs.nu/tmp/molz_hatarsynci.mp4

If you listen carefully you can hear that the audio loop at the end of the plasma goes on four times on Hatari and three times on the real STe. It is easy to spot the wrong sync after the spectrum 4096 image were the colours flash in sync to the drum when the chunky fullscreen effect begins.

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3.
Space Tale / ICE
http://files.dhs.nu/files_demo/spactale.zip

a) Lower border in the intro with the two big sprites is not opened

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4. 
The Saw / Offbase
http://pacidemo.planet-d.net/archives/THESAW.ZIP

a) Audio is garbage


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5.
STNICCC 2000 / Oxygene
http://files.dhs.nu/party/stniccc2000/oxygen.zip

a) Vector animation ends after a while, music continues

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6.
Fullparts by Hemoroids
http://stknights.free.fr/uploads/fullparts.zip

a) The overscan flickers when a new line begins in the text displayer

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7.
Brace by Diamond Design
http://pacidemo.atarizone.com/archives/BRACE.ZIP

a) In the scrolltext screen with split low/med-res parts, the rasters flicker

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--
Anders Eriksson
ae at dhs.nu     http://www.dhs.nu/
ae at atari.org  http://www.atari.org/



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