🚀 go-pugleaf

In article <PCG.92Dec19162224@decb.aber.ac.uk> pcg@aber.ac.uk (Piercarlo Grandi) writes:
>On 13 Dec 92 05:00:19 GMT, johnl@iecc.cambridge.ma.us (John R. Levine) said:
>
>(somebody)> NeXTStep is said to not run on the Cyrix 486 chips because
>(somebody)> "they are not real 486's".  No one has come up with a
>(somebody)> reliable reason _why_ NeXT doesn't think they are "real
>(somebody)> 486's" or why NeXTStep won't run on them.
>
>The most probable reason seen so far is that there are some small
>supervisor state differences between the Cyrix and the Intel part.  If
>so, I would venture that it is about enabling (and then flushing at the
>right moment) the cache on the Cyrix.  It is not necessary to do so, but
>if one does not (and one has to do so on most old 386-like motherboards
>on which the Cyrix part is usually mounted) then performance is little
>better than with a 386.
>
>johnl> I don't have any real data, but I expect the problem is that the
>johnl> Cyrix chip doesn't have a floating point unit.
>
>No, this cannot be the reason. As a rule the Cyrix 486DLC CPU chip is
>sold with the Cyrix Fasmath (a 387) coprocessor, the combo being touted
>quite reasonably as a 486DX equivalent.
>
>Moreover NeXTStep is said to run on the 486SX Intel chips, and those
>don't have a corprocessor either.
>
>FUD, FUD. Ah Intel, Intel. :-)


I don't see where this has anything to do with Intel.  Cyrix decided that
they could make some money by cloning a best selling CPU chip.  Obviously,
they have missed something.  A curious individual with a 486DLC system, a
486DX system, two logic analyzers, and two NeXTStep bootdisks should be
able to track down the problem.

-- 

Rick Kelly	rmk@rmkhome.UUCP	unixland!rmkhome!rmk	rmk@frog.UUCP