Query: Is model=CD32 functioning correctly?

[giantclambake]

I'd actually stumbled across some oddity wrt CD32 emulation before ...see #1377 ... at the time, I thought it to be an isolated example, caused by the fact the intro anim was very different from the layout of the title itself (game assets), so I just left 'sleeping dogs lay' as the expression goes --- now I just found this example, and it very much looks like a bug...

To recreate:

Download & unpack this CD32 title -> http://ftp2.grandis.nu/turran/FTP/TOSEC-ISO/CD32/Commodore%20Amiga%20CD32%20-%20Games%20-%20%5bISO%5d/Kang%20Fu%20(1996)(ALTER%20interservice%20-%20Greed)%5b!%5d%5bAmiga-CD32%5d.zip

NOTE: This title ran very poorly with the base CD32/2mb+8mb '020 machine type -- the 2 beginning splash screens were 'shimmering' like these were being displayed in a hires interlaced mode, and once the game menu screen appears, music is totally broken and graphics very bad, with these images appearing much smaller than the emulation window itself...(odd). I figured the best idea, was to first see if I could tweak amiberry settings, to get this title running 'properly' --- this is the resultant config.uae file I used, that addresses all these problems...

Kang Fu (1996)(ALTER interservice - Greed)[!]CD32.uae.gz

With the above configurata done (and Kang.Fu.1996.ALTER.interservice.-.Greed.CD32.uae is in conf/ ), I start the emulation by double-clicking on the Kang Fu (1996)(ALTER interservice - Greed)[!]CD32.cue file icon --> this works as expected, with amiberry direct loading the .cue file, loading in the associated config.uae file, and starting the emulation immediately....

• CD32 bootscreen comes and goes...
• the Greed splashscreen is displayed...
• the Kang Fu splashscreen is displayed...
• the intro screen and music starts... //lasts for a minute or so...
• intro screen & music dismissed, replaced with water-color image //load screen...
• water-color image is replaced, with scrolly Hi Score overlay, but the image is smaller and shifted, and graphics/music stutters badly...

• hit F12 key, pops GUI --> hit F12 key again to dismiss GUI and resume emulation
• water-color image, with scrolly Hi Score overlay is now correct size, and graphics/music working correctly

Expected: Hitting the F12 key twice should not be required to correct the graphics anomaly (which shouldn't happen in the first place ofc ;)

Indeed, I can't even imagine how the F12 key/GUI are participle here, but, there it is =)

Any ideas?...obscure bug of some kind?

TIA

[midwan]

The two screens shown on startup are indeed Hi-Res Interlace, so if your line mode is set to Single, they will appear as flickering.
Looking into that, it appears that the default setting in amiberry.conf was indeed to have line mode as single, which was useful when running on slower platforms, but no longer an issue after the split.

I've changed that to be Double, to avoid the interlace artifacts - but of course, it won't overwrite the setting you may already have now, so you can change that manually if you want.

The other issues I could see here, are related to the audio playback from the (virtual) CD. I think the CDDA support needs some improvements, but it's going to take a bit of work to get done.

[giantclambake]

Thanks... with default_line_mode=1 that does indeed fix display of the first 2 screens.... that's a win...

...but again, this title runs horribly on the CD32 2+8/020 machine emulation. I think I need to stop right there, and query why this is so...ie; typically speaking, CD32 emulation is better than this OOTB... retest...

• double-click on the Kang Fu (1996)(ALTER interservice - Greed)[!]CD32.cue file icon... //Note: no associated config.uae
• CD32 bootscreen comes and goes...
• the Greed splashscreen is displayed...
• the Kang Fu splashscreen is displayed...
• the intro screen and music starts...horribly, with music playback and graphics overlay stuttering badly
• hit F12 key, pops GUI --> hit F12 key again to dismiss GUI and resume emulation
• NOW graphics and music working as expected

This also happens when it gets to the highscore scrolly/music ...ie; the image display is now correct, but you still have to hit F12 twice to fix the music/graphics stuttering.

..so.. one bug down, and one yet to be squashed here I guess ;)

[midwan]

I haven't found a proper solution yet, but I noticed that if disable the Cycle Exact (Full) option in the Chipset panel, the audio does seem to behave better in the intro sequence.

There are still some corrupt graphics flashing on the screen in the same sequence, instead of the normal rotating logo that should be there. But that happens on WinUAE as well, so I think it's a different kind of issue. I managed to get it to show once during my tests, while opening the GUI, fiddling with settings then going back, but never again - so I'm not sure what did it.

[midwan]

Reported to WinUAE regarding the graphics corruption: tonioni/WinUAE#331

[giantclambake]

Thanks ~ interesting, your description of the issues differs slightly by the sounds of it, but no problem, that's what YT is for ;)

https://www.youtube.com/watch?v=Y-qYqgAdEh4

It's difficult to pin down, because the mere act of opening/closing the GUI effectively corrects the situation ~ ergo, you're left with setting an emulation option before you start the title, so hitting the F12 isn't part of the test...

This is what I found -- starting from the GUI with expanded (2+8) CD32 preset, changing one of the following options avoids the issues with this title...

• GUI -> CPU and FPU panel --> set 68020 CPU Speed to 'Fastest possible' ....or.....
• GUI -> CPU and FPU panel --> set CPU type to 68030 ....OR.....
• GUI -> Chipset panel --> disable Cycle Exact (Full)

Somehow this reminds me of a title I was testing a number of months ago (I forget the title name now), wherein Toni had intimated this was something odd in the chipset code, which has many little hacks in it, which is why he was rewriting the chipset code....and that he likely wouldn't look at issues like this again, until the chipset code rewrite was done. Perhaps this issue is also related here? Sitting on hands....

[midwan]

Toni replied, the gfx glitches are most likely due to 68020 timing issues, so they won't get fixed anytime soon.

There's still the issue that only happens in Amiberry, regarding the sound problem depending on the CPU/Chipset setting, which does not happen on WinUAE. I haven't figured out why that is, yet.

In any case, this is not a generic case about CD32 emulation I think, more about this specific title that behaves erratically.

[giantclambake]

Yeah, saw Toni's comment ~ you're right, if it doesn't happen in WinUAE then it shouldn't happen in amiberry either ... ideally speaking ....

As to whether of not this is a CD32 emulation issue, or title specific, I'll just have to keep testing CD32 titles to divine ;)