How CPU's work (was Re: Hi, I'm new...)

Chuck Guzis cclist at sydex.com
Sun Aug 6 23:15:54 CDT 2006


On 8/6/2006 at 10:41 PM Ray Arachelian wrote:

>It's worth a read to get a feel of the excitement the 68K caused back in
>the day when it was introduced.  Some of it is very funny, there's one
>issue where the author compares an Intel FPU to the 68000 running
>software floating point routines, and guess what, the 68000 actually ran
>FASTER!  :-)

I never did benchmark the 68881.  IIRC, the 68K was a big deal in the fab
business.  I think it used the then-very-new 3 micron technology.  My
biggest disappointment was that the CPU instructions weren't resumable
after a fault--i.e. with those 24 bits of address, there was no possibility
of virtual memory implementation.  I did hear of a scheme for using two
68Ks, one running a half-clock ahead of the other to get around this, but
that was prohibitively expensive.  16 MB sounded like a huge amount of
memory back then.

Cheers,
Chuck









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