OS4 and 680x0 emulation

Hello,

i've installed OS4 and restored a backup from my old calssic amiga (68060)....
when i start voyager (the 68060 optimized version) it crashed at startup. then i installed the 030 version (with fpu) and now voyager started up. :-)

did the 68k emulator in OS4 not emulate the 68060? which processor doe it emulate?
have i to remove all my 68060 comiled programs and subst it with a other version?

thanx!

tanarri

- subject line edited by mikeymike - short and sweet is good :-) -

[mikeymike]

Try the original binaries, see what happens?

[DaNi]

The os4 uses petunia for emulate all 68k codes, the pre-release have built-in the 020 emulation, but the petunia full emulates 040+fpu (no mmu) http://amigos.amiga.hu/rachy/petunia.html,i think emulating programs or libraries using mmu can have any type of problems. The best method is install all 68k soft and choose the cpu for dont have problems.

Cheers

[xeron]

To be honest, expecting 68k Voyager to do anything but crash, even on a real Amiga, is at best unrealistically optimistic ;-)

Well written 68060 optimised applications will run fine under OS4, but whether it is best to install the 020 or 060 version i'm not sure.

[alx]

Well written 68060 optimised applications will run fine under OS4, but whether it is best to install the 020 or 060 version i'm not sure.

IIRC the emulation can emulate most 040 specific code, but programs with an 040 version tend to assume that there's an MMU (which obviously won't run, as DaNi says) - something like that at least :-D

[DeQuevedo]

Hi All

As far I know, Petunia ATM is included in Os4 as a interpretive emulator, an its a stippeddown version of the full power 68k emulador.

Its actually emulating  a 68020 with FPU but NO MMU, so the best choice for me is choosing the 020 / 030 version at the installer of the software, in order to avoid crashes.

The JIT version of petunia will emulate a 040 FPU (let see if MMU will be emulated or not), so yes, If were you I will erase all the 060 stuff of the backup in order to try it on Aone.

Best Regards

-DeQ

[Framiga]

Hi all,

don't use 060 optimized apps under AOS4.

020-040 should works fine.

Ciao

[Karlos]

I've ran stuff compiled for 020-060 with no problems at all on OS4. The user mode of these chips varies very little. It's only when an application directly uses some specific (usually supervisor mode) function of a processor (such as MMU or direct cache manipulation) you get problems.

In the best intrests of compatibility, since the interpretive emulator emulates 68020 + FPU I'd be inclined to use either 68020+FPU or generic 68020-68060+FPU (the latter doesnt have any FPU instructions the 040/060 can't directly manage) binaries first. It's most unlikely that there would be any noticable speed gains from an 060 optimised binary over an 020 one when dealing with emulation anyway.

[Kronos]

And what normal apps use MMU ? None !!
Only OS-patches and debugging-tools use it.

Dunno bout Petunia, but most emus will run best with 020/881 when the app uses floating-point and 040 if it doesn't since the emus  emulate an 040 with FULL FPU.

Running 060 binaries is a bit counter-productive since all improvement over the 040 are in the way it executes the SW, something that will make no difference for the emu.

It may even be that the emu has a harder time with the specially aranged instruction in a 060-bin (to make full use of it's parallel features) compared to a straight-down 040-bin. The instructions missing in the 060 compared to the 040 will also mean a small performance downgrade as the app will call replacement routines instead of simply useing the 040-instructions (which is supported by the emu).

[bloodline]

Does the 060 have a conditional move instruction?

[itix]

If you are installing browser and have fast internet: use datatype loaders :-D

[KennyR]

I've been using 68k emulation for over a year in MorphOS, and I've set up UAE too on the family PC. I think that, from a user point of view, CPU optimisations don't matter the slightest for emulation. 060 code optimised for branching won't run any faster than 000 code with old instructions. Even if there was a difference, modern CPUs (even as "slow" as a G3) won't let you see it. Not even without JIT.

[rachy]

Let's clean up the situation for everybody's good:

1. The Prerelase AOS4 CD does not contain Petunia in any form. It uses the interpretive emulator (formely known as Black box).

2. The interpretive emulator knows all opcodes up to 040+881, and a 060 has even fewer opcodes than a 040, so this cannot imply the crash at all. The system reports only 020+881 for compatibility reasons, but it does not bother too much. You can install any software what is not using MMU and special tricks/traps to determine FPU type and similar things on a non-system friendly way. (Like identify.library does - if I remeber correctly the name of it.)

3. Just as KennyR wrote: 68k processor optimized versions won't be faster normally under the emulation at all. (Probably the specially 040 optimized with MOVE16, but it is highly doubt.)

So all in all: if something crashes that is not caused by a missing opcode from the emulator. I suggest to install 020+881 software. :-)