How can I get FS-UAE more accurate?

[Tigerskunk]

I have really bad issues with FS-UAE displaying everything fine, and when I test on real hardware stuff, especially bitplanes, seem to be wonky and doing weird shit.

This started when I implemented fetch x2. Everything looked working on FS-UAE, and on real hardware it looked all kinds of distorted. Got that solved, but it was really stupid having to copy stuff around to get it working.

Now I have problem with wonky bitplanes (which I guessed is somehow related to blitter or CPU load), and same problem: FS-UAE displays it perfectly, and on my real A1200 it looks all kind of weird and distorted.

Is there a "switch" I can turn on in the settings that prevents this, and do the same things happen on WinUAE? Maybe I need to use that one.

This really starts grinding me down.

Thanks for any help on this issue, mates...

[JoeJoe]

Mostly the problem is due to unclean programming. For example, the memory of the emulators is always filled with 0x00. This is not the case with the real hardware. Also registers are not filled with 0x00 at program start.

[Tigerskunk]

Originally Posted by JoeJoe

Mostly the problem is due to unclean programming. For example, the memory of the emulators is always filled with 0x00. This is not the case with the real hardware. Also registers are not filled with 0x00 at program start.

With both instances I experienced with FS-UAE displaying everything fine while on real hardware it was all botched it had nothing to do with these kind of things.

FS-UAE seems to have problems displaying certain AGA peculiarities.

Example for you: do a copper command each raster line setting $0100 to your wanted amount of planes two times.
FS-UAE will display it like it's no problem.
On my real A1200 the screen will start to freak out.

[Galahad/FLT]

Best test always is run it through winuae, its more accurate for cases like this because Toni has explicitly tried to ensure that behaviour is the same between emulated and real Amiga.

[Tigerskunk]

Originally Posted by Galahad/FLT

Best test always is run it through winuae, its more accurate for cases like this because Toni has explicitly tried to ensure that behaviour is the same between emulated and real Amiga.

Thanks mate, will give WinUAE a try.
Getting a bit tired of these kind of bad surprises by now with FS-UAE.

[FrodeSolheim]

Originally Posted by Galahad/FLT

Best test always is run it through winuae, its more accurate for cases like this because Toni has explicitly tried to ensure that behaviour is the same between emulated and real Amiga.

It shouldn't behave any different in FS-UAE compared to WinUAE. If it behaves differently, it should be only due to different "UAE version" (for example, FS-UAE does not include the updates from the most recent WinUAE versions yet. *), or different configuration.

- FS-UAE 3.x should have the same compatibility as WinUAE 3.3.0 beta 2
- FS-UAE 4.x preview builds should have the same compatibility as WinUAE 4.2.1.

I'm not saying don't test with WinUAE. In fact, it is a good idea. If you find something that works in WinUAE and does not in FS-UAE (with the comparable version), I'd like to know.

Also, please note that Amiga 1200 emulation isn't 100% correct (neither in FS-UAE nor in WinUAE) due to some (timing) internals of the 68020 CPU not being known.

[Galahad/FLT]

Originally Posted by FrodeSolheim

It shouldn't behave any different in FS-UAE compared to WinUAE. If it behaves differently, it should be only due to different "UAE version" (for example, FS-UAE does not include the updates from the most recent WinUAE versions yet. *), or different configuration.

- FS-UAE 3.x should have the same compatibility as WinUAE 3.3.0 beta 2
- FS-UAE 4.x preview builds should have the same compatibility as WinUAE 4.2.1.

I'm not saying don't test with WinUAE. In fact, it is a good idea. If you find something that works in WinUAE and does not in FS-UAE (with the comparable version), I'd like to know.

Also, please note that Amiga 1200 emulation isn't 100% correct (neither in FS-UAE nor in WinUAE) due to some (timing) internals of the 68020 CPU not being known.

I dont want you thinking I'm slagging FS-UAE off, but in my experience when it comes to programs or code failing, the side effects in winuae are the closest to the real thing where in 99% of cases, the same behaviour is exhibited on real as well which is perfect for diagnosing problem software.

Lots of other emulators try and mask issues whereas Toni goes out of his way to ensure that winuae acts the same.

[Muzza]

Consider the ROM you are using too. I went through similar problems when I started programming on the Amiga. More than once the difference in behaviour between emulation and real hardware was using the AROS ROM on WinUAE/FS-UAE. Using a genuine ROM under emulation would yield different results.
Now when I have a problem, I tend to run across different ROMs, different versions of emulators, different emulator settings (lots of RAM, little RAM, different processors) and real hardware. Bugs in my program will often cause a crash in one combo, but not the others.