Demo no longer runs on latest WinUAE - assistance?

[Foebane]

This demo here:

http://www.pouet.net/prod.php?which=56885

It seems this production has always been troublesome with WinUAE, looking at Google, but on a version of WinUAE released earlier this year I was more or less able to get it running to the end, albeit with some bitplane flicker.

However, trying it now on WinUAE 3.2.1, it starts off OK until the air-raid siren ends and the music begins, but it then stays black and then the demo locks up with a tone, and eventually gurus (if I recall correctly).

I used exactly the same settings as I did before, and I can't figure out how to get it running.

Any ideas?

[Toni Wilen]

Cause probably is very unexplained black screen issue in 3.2.1 (which I can't duplicate and only happens in some systems or something) if 3.2.0 works.

3.2.2 beta will appear very soon.

[Saghalie]

Not sure if this will help but whenever I tried running it, it crashed using the 060 chipset. I ran it using the 040 chipset and it worked just fine.

Regards,

Saghalie.

[Foebane]

I used to run it on 040 as well, but it doesn't work now on 3.2.1 and 3.2.0 neither.

It could be down to my config, but then I'm not sure about how the different memory types work on the higher-end systems. My A4000 setup is: 8Mb Chip, 256Mb Z3 Fast and 8Mb Motherboard Fast, but I think this may actually be overkill, and I was told that too much memory can be a bad thing for the Amiga. I'm simply attempting to use a config that covers everything I'm likely to run. What's the best thing I can do?

[Foebane]

Couldn't solve the problem in the end, but just went back to 3.1.0 instead, where it worked fine, despite some odd flickering.

[Toni Wilen]

If you really want some help, you need to include all required information, most importantly config file and log files (log file from both working and non-working version)

EDIT: Make sure config makes sense, "impossible" config = you are on your own, nothing is guaranteed when running not-that-system-friendly programs like demos or games.

EDIT2: Also always test without JIT (if it was enabled).

[Foebane]

I have just run the same files (WB, demo, configs) on versions 3.1.0 and 3.2.1 of WinUAE, and these are the logs I produced (Dropbox):

https://www.dropbox.com/s/n6fl1xqrse...3.1.0.zip?dl=0
https://www.dropbox.com/s/281bfopyhe...3.2.1.zip?dl=0

I ran the demo on 3.2.1 without JIT and it progressed a bit further, starting the 3D mainpart, but it eventually froze in the same spot (ran twice).

Hope the files help, and tell me if my RAM config is possibly to blame, as I'm not sure if there's conflicts or not.

[jbenam]

You can start by reducing the Chip mem to 2MB - no Amiga ever released had more than that because of an hardware limitation

Have you tried with a Quickstart config?

[Toni Wilen]

Black screen seems to be JIT FPU related. Probably something related to 64-bit compatibility update.

EDIT: It was introduced in 3.2.0b16.

[Foebane]

Originally Posted by jbenam

Have you tried with a Quickstart config?

My hardware configs are based on the Quickstart ones - I just select the model I want from Quickstart, then tinker with the settings to get the ones I want and then save.

[Toni Wilen]

Bug found (It was FPU rounding related) and technically bug was not my fault

Cause for flashing in demo probably is the usual: too fast CPU/chip ram access speed.

[Foebane]

Originally Posted by Toni Wilen

Bug found (It was FPU rounding related) and technically bug was not my fault

Explain? I'd love to hear where you tracked it down.

[Toni Wilen]

It was side-effect of Visual Studio "feature".

32-bit FPU rounding mode function changes both FPU and SSE2 rounding mode.

64-bit version only changes SSE2 rounding mode. (Apparently because x87-like FPU is considered legacy feature and use of SSE2 is the way to do it in 64-bit Windows because all x64 CPUs have it). There is no function to set FPU rounding mode..

320b16 introduced code (by Frode) that sets FPU rounding mode that works in both 32-bit and 64-bit, to allow 64-bit version to work correctly with JIT because it uses x87 FPU instructions.

SSE2 unit rounding mode was not anymore updated and so far everything appeared to work but some function used SSE2 instead of FPU (compiler decided SSE2 is better than x87 FPU instruction): unexpected rounding mode was used in some situations and this demo didn't like it at all.

Fixed version always sets both, x87 FPU and SSE2 rounding mode.

UAE maps 68k FPU instructions to host FPU instructions for performance reasons. Some emulators use softfloat library for accuracy, especially exceptions can only work correctly if using softfloat, fortunately practically no one uses FPU exceptions.

[Foebane]

I see now, thank you very much!