OS4 Classic, why disable the 68k ?

[vox]

Hi,
I just wondering why the onboard 68k is disable on the Classic version of OS4 ?
If it wasn't, would it be possible to run things without 'runinuae' or the likes ? or maybe it will speed up this as it wont need to emulate the 68k ?

Simplest answer is that whole OS4 is PowerPC and running native PPC apps is whole level of new experience. 68k WB friendly software will be working under Petunia, maybe even faster then 040 if PPC is 604 I suppose. AGA chipset should be even acessible? so even more software should work? (has anyone tested e.g. apps that used to crash on A1 on Classic OS4?
http://www.intuitionbase.com/ossoftware.php?category=3&letter=NON

Plus the context switching was known slowdown problem of PPC cards, so your PPC experience is full now :-)

[vox]

You are mistaken. The native chipset is still supported in OS4 on classics. Even hardware banging stuff tends to work since the hardware being banged is actually present.

Stuff that is critically dependent on 68K v custom chip timing might not work so well but then that's often a problem for faster 68K processors too.

Unless you are talking about using UAE on the classic machines, in which case, yeah, it's pretty slow.

Must say that some kind of "Radeon is emulating AGA, or FPGA on SAM 440/460" would be nice thing to see just because with AGA chipset not being emulated and Petunia 68k JIT it would make OS 4.1 backward compatible without need for UAE + almost all WB and productivity apps working.

In these terms Classic OS 4.0/4.1 is most backward compatible OS 4.x just because AGA is onboard (and supported by OS), making UAE mostly not needed.