I posted the "BeOS & XP & XP" question. I tried the patch and it didn't work. After re-reading the instructions I think I know why. The SSE instructions in an Athlon XP are not the problem, BeOS can use SSE. Removing them from the kernal does nothing. The boot file will still detect them in the processor and set itself up for an Intel. Then it uses Intel specific instructions (other than SSE) that the Athlon can't handle. That's how I understand the problem anyway, correct me if I'm wrong. I think what's needed now is a simple JUMP instruction at the beginning of the test for SSE to the point where the boot file sets up for an AMD.

You're right, the problems isn't the fact that BeOS doesn't support SSE--it does. The problem is that in AMD's implementation of SSE, the AMD processor actually identifies itself to the OS as an Intel processor. When BeOS tries to issue certain Intel-specific instructions, it crashes.

Here's information I posted some time ago about this:

Here's the deal:

The Palomino core used in the Athlon XP includes a full implementation of Intel's SSE instruction set. So far, no problem--BeOS fully supports SSE. But, AMD did something pretty weird. In their AMD's implementation of SSE, they force the Athlon to report that it's *not* an Athlon but an Intel chip! In effect, with AMD's SSE enabled, the Athlon misrepresents itself to the system as an Intel chip. When BeOS starts to load, it asks the system about the processor, BeOS is told that it's an Intel chip. When the BeOS kernal, thinking it's talking to an Intel chip, sends instructions to the CPU, it crashes the system. The Athlon XP tells BeOS it's an Intel chip and when BeOS treats it like an Intel chip, it crashes.

Disabling the AMD's wacky implementation of SSE solves the problem. This can be done at the motherboard firmware level.

At least one motherboard manufacturer provides boards that allow the AMD SSE to be disabled. All that's required for a motherboard manufacturer to provide this feature is to update the BIOS. Hopefully, Tyan, Asus, and the rest will follow suit and add this option.

I have no idea why AMD chose to do this with their SSE implementation. Perhaps they had a compelling reason to do this, but it seems completely insane to me. I'd still rather have an Athlon XP than anything from Intel, though.

If you have an Athlon XP system and can't boot BeOS, contact your motherboard manufacturer and ask them for a BIOS update so you can turn off SSE.

So why can't a command line be put in while in the BeOS advanced safe boot screen?
I do understand that the Model 7 Duron and XP/MP and moble4 all seem to use a similar core and there is patches out there to rebuild the kernel.