[vcf-midatlantic] Computer math (was 33! science project)

Dave McGuire mcguire at neurotica.com
Thu Mar 22 12:48:30 EDT 2018


On 03/22/2018 07:11 AM, Jeffrey Jonas via vcf-midatlantic wrote:
> Long long ago, I ran Whitesmiths' "C" compiler
> under CP/M on a Z80 system but forgot what data types were "native".
> I also have PL/1 for CP/M.
> 
> While "native" data types are definitely faster
> (word-sized integers), even the Z80 had math co-processors.
> Before it was on-die, there was a variety of 8087 math co-processors
> by Cyrix, AMD as well as Intel.
> So speed and precision were far from "standardized".

  The Z80 did not "have" math coprocessors.  There is no provision for
tightly-coupled coprocessors on the Z80.  That functionality first
appeared (in that side of the world anyway) with the 8086, for which
there were several coprocessors (not just math) designed.

  There are a number of generalized math coprocessors that could be made
to work with the Z80, like the venerable Am9511.  With all of these
designs, the Z80 never knew it was there, it was just another device
mapped into I/O or memory space.

            -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA



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