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GideonZ / 1541ultimate

Official GIT archive of 1541 ultimate II sources
GNU General Public License v3.0
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Emulated SID in 1541U2+ does not work in Skyfox #185

Closed rittwage-zz closed 3 years ago

rittwage-zz commented 3 years ago

When you load the original game, it starts emitting a high pitched sound and never plays the audio during the title screen.

markusC64 commented 3 years ago

I cannot confirm this. Although audio is quite quiet, it is undoubtedly present on my C128 with 1541 Ultimate II+.

I am testing with the attached image from the original disk. skyfox.zip

Edit: Of cause at the speakers connected to the U2+.

rittwage-zz commented 3 years ago

I have a second SID in the right channel snooping at $D420. This channel plays such a loud noise you can't even hear the normal Skyfox music in the other channel. It could be a bug where the game touches the second SID at $D420, but at least with dual regular SIDs or an ARM2SID, it doesn't happen.

markusC64 commented 3 years ago

Clearly, snooping does not know to differ between I/O access and access to the underlaying ram. Which means that enabling only the channels you currently need is strongly adviced.

There is no known method to differ between I/O access and access to the underlaying ram on the expansion port other then soldering a wire to the PLA output. So Gideon will have no chance to improve that.

rittwage-zz commented 3 years ago

Got it, thanks!