🚀 go-pugleaf

>>NeXTStep is said to not run on the Cyrix 486 chips because "they are
>>not real 486's".  No one has come up with a reliable reason _why_ NeXT
>>doesn't think they are "real 486's" or why NeXTStep won't run on them.

>I don't have any real data, but I expect the problem is that the Cyrix
>chip doesn't have a floating point unit.  Next's own systems have all
>had standard FPUs, and reviews of NeXTStep say that it won't run on a
>486SX, only a DX.

A 10/21/92 semi-official net posting on NextStep claims it runs on SXs:

   General Requirements:
   CPU - 486 based PC Compatible Computer. This includes 486SX, 486DX,
   486DX/2. Future Intel Microprocessor designs in the x86 family will
   also be supported. ISA or EISA expansion bus. 486DX and 486DX/2's are
   recommended for better performance.

   Will NeXTSTEP 486 run on the Cyrix 486SLC?
   No. The Cyrix chip not a true 486.

I asked for an explanation of "true 486" in comp.sys.intel. A Next person
seemed to imply that Next didn't want to bother resolving the supervisor
state differences between the chips. Nothing very convincing. I had a theory
involving "arrogant propeller-heads", but the Next person didn't agree with it.

My guess is that NextStep is sluggish enough that Next saw no reason to bother
with the Cyrix parts, which are lower performance than Intel 486?Xs.

I've also seen Intel apologists and employees repeat the "not a 486" claim in
various groups. They've succeeded admirably in their primary goal, which is
to sow Fear, Uncertainty, and Doubt as widely as they can. What I haven't seen
yet is an explanation. I'll ask the question again here:

	Please tell me exactly WHY the Cyrix isn't a 486? What is it that
	Intel feels is the essence of a 486?

	Let me say a priori that a response of "made or licensed by Intel"
	isn't sufficient in and of itself.