Understanding UNIX, X86, and Power PC

OS X is a UNIX OS, so I'm not quite sure what you're asking.

The operating system runs on top of the processor. Different processor architectures have different instruction sets, a different language for getting things done. OS X already runs on both the PowerPC architecture and the x86 architecture, and has done so since they originally started working on it.

Most programs don't do any architecture-specific stuff, but they'll still need to be recompiled to take full advantage of the change. Any applications that have done any assembly-level optimizations will have to be rewritten (at least the sections that are written in assembly).

Since your original question confused me, maybe you could explain exactly what you're looking for (as OS X is already Unix at its core).

I was wondering about whether there would be a necessary change from UNIX when there was a switch to x86. Based on your response it seems the answer is no.

That is correct. OS X will still be the operating system after the switch, and it will still have, at its core, BSD Unix. It'll just be recompiled to run on Intel chips.

Well, "recompiled" is glossing over quite a bit. 🙂

To answer the original poster, it's still UNIX, but MacOS X must be "ported" to x86 chips, a process akin to translation. For example, given books are often available in different languages but with the same content; the same goes for operating systems.

it's still UNIX, but MacOS X must be "ported" to x86 chips

And according to Steve Jobs keynote speech at WWDC, when he announced the Intel transition, OS X has been ported and running on the Intel processor (in the secret underground Apple labs) pretty much ever since OS X was first released over 5 years ago.

So it's mainly just a matter of continuing to build OS X for both platforms as updates and enhancements are added.

Steve

William,

From my original post:

OS X already runs on both the PowerPC architecture and the x86 architecture, and has done so since they originally started working on it.

So, OS X doesn't need to be ported, it's been running on PowerPC and x86 since the beginning.

well...two different osx builds...