AmigaOS 3.x programs on AmigaOS 4.x

[DavidF215]

How well do programs and apps created and compiled for AmigaOS 3.x perform on AmigaOS 4.x?   Do they run well, crash, run slower, have odd behaviors, etc?

[tboeckel]

That very much depends on the application.

If a program crashes with OS3 then it will definitely crash with OS4, too. It may crash with OS4 even if it runs very stable with OS3, since OS4 catches lots of invalid memory accesses which went unnoticed with OS3.

Usually they will run faster on OS4, because the PPC CPU is faster than the 68k CPU, even without JIT execution.

[xeron]

On the whole, compatibility is very good with system friendly apps.

If you have any apps in particular, just mention them here, and i'll let you know if they run OK (if i have them...).

[amigadave]

tboeckel wrote:
That very much depends on the application.

If a program crashes with OS3 then it will definitely crash with OS4, too. It may crash with OS4 even if it runs very stable with OS3, since OS4 catches lots of invalid memory accesses which went unnoticed with OS3.

I hope that is not true!

I would think that the developers of OS4 are smart enough to enable OS3 apps (the ones that don't bang the hardware) that run well, to continue to run well on OS4.  From the wording of your quote above, it sounds like you are saying that OS4 crashes while running some OS3 apps that usually run fine on OS3, but they crash an OS4 machine?  

I would think that the OS4 developers would have a better solution for trapping bad code in an OS3.x application instead of allowing it to bring the OS4 computer down.  Please tell me it works that way.

Usually they will run faster on OS4, because the PPC CPU is faster than the 68k CPU, even without JIT execution.

If they don't, then what was the point of porting the AmigaOS to PPC native?  I am sure they must run faster. :-D

[cv643d]

For example, HippoPlayer is a stable module player on 3.x. Never crashed on me before. On OS4 it works nice but everytime I quit it I get an error.

DeliPlayer and EaglePlayer refuse to play modules (or crashed), too bad since they would really work good on PPC to be able to enjoy multiple graphics scope and such.

[xeron]

amigadave wrote:
From the wording of your quote above, it sounds like you are saying that OS4 crashes while running some OS3 apps that usually run fine on OS3, but they crash an OS4 machine?  

On OS3.x, if you read from or write to somewhere you shouldn't, nothing stops it from happening. It could be harmless, or it might have corrupted something which doesn't immediately cause a problem, but might cause a crash later on (maybe even when you're using some other innocent piece of software that appears to be the cause of the crash!).

OS4 traps illegal reads and writes and suspends the program, giving a lot of useful information for developers to fix their broken software. Unfortunately, some old software is no longer developed, and so will always remain broken, but you can quite often continue execution of the program itself.

One upshot of this is that software developed for OS4 tends to be very stable, because OS4 provides excellent debug information when applications do misbehave, and actually, a LOT of the 68k software i used to use on OS4 has been replaced with new native software anyway.

But to get back to your original point, a LOT of OS3.x system friendly software runs just fine on OS4.x without issue.

If they don't, then what was the point of porting the AmigaOS to PPC native? I am sure they must run faster

Oh yes, apps run a lot faster on the PPC. Not only is the emulated code faster, but since the operating system and all its libraries are PPC native, they benefit from that extra speed too!

[amigadave]

@xeron,

Thanks for clearing that up.  I didn't think that the developers would allow old, badly coded OS3.x programs to crash the entire AmigaOS, but that is what the original comment I quoted sounded like he was saying.

[DavidF215]

Thanks for the feedback. I was hoping that 3.x programs would run decently on 4.x systems.

I have StormC v3 from my Amithlon CD. Does anyone know if upgrading to StormC v4 is worth it, or if an alternative, better compiler for 3.x/4.x exists?

Also, has the BOOL type in AmigaOS been updated to the ANSI C bool type? I was compiling some code I brought over to AOS that had bool types but StormC v3 made me change from bool to BOOL and false to FALSE along with adding an include statement for the boolean type--an odd requirement I thought.

[SamuraiCrow]

StormC 4 is worth it because just about anything newer doesn't support graphical use of the debugger and anything older doesn't support C++ very well.

bool should be supported on Storm C++ 4.