Question about OS4

[Themamboman]

Okay, I've read on and off about OS4 for a while.  One of the best features I'd read about it was its support for PPC's.   I was then under the assumption that it was PPC-only (no 68k support).

However, I was wondering just recently if this was true?  Is OS4 PPC-only?  Are those of us using UAE stopped at 3.9 until we can afford the PPC machine?

Just curious, because I remember Apple's transitional OS's supported both PPC and 68040 for at least 2 or 3 releases before going PPC only.

[alx]

Sorry, OS4 is completely PPC only.  A very small amount of code will  be ran through a 68k JIT emulator, but all the main stuff (including the entire kernel) is PPC native - and won't run under any emulator, as no Amiga emulator supports PPC.

I don't know much about MacOS, but they made the jump from 68k to PPC a long time ago, when the 040 was pretty fast - nowadays it cannot match current PPC hardware in any way.

[MasterOfReality]

Is OS4 PPC-only?

Yes

Are those of us using UAE stopped at 3.9 until we can afford the PPC machine?

Yes, although certain bits and pieces may become available for UAE (the TCP/IP stack, for example).

Just curious, because I remember Apple's transitional OS's supported both PPC and 68040 for at least 2 or 3 releases before going PPC only.

At the time PPC wasn't that much better than 68k in speed terms so a smooth transition made sense. These days we are in desperate need of better HW and companies like Eyetech need to make some money, so it makes sense to make people upgrade.

[Rogue]

Yes, OS 4 is PowerPC only. Certain invidiuals might be tempted now to jump in and tell you that is being developed on Amitlon (untrue). I just read somewhere else that it had been running on 68k before (untrue).  Fact is it is PPC only. ExecSG has never existed as 68k.

It was a matter of perspective really. Maintaining two separate code bases for 68k and PowerPC would be too much of a hassle. Apple's budget is definately a bit larger than ours.

Besides, AmigaOS 4 needs an MMU. To the best of my knowledge neither UAE nor Amithlon nor AmigaOS XL supports an MMU. This has nothing to do with virual memory (as in swapping to disk), which can be disabled, but rather because of the virtualized memory architecture. This rules out emulated systems.