Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

Noel Chiappa jnc at mercury.lcs.mit.edu
Sat Sep 17 14:45:29 CDT 2016


    > From: Guy Sotomayor Jr

    > Why? What does the width of the ALU have to do with the "bitness" of
    > the architecture? If the programmer's view is 8-bits .., what does it
    > matter (other than performance) what the width of the internal data
    > paths or ALU are?
    > It's interesting from an implementation point of view but not really
    > anything else.

What he said (and others made the same point).

When talking about processors, "Architecture" = 'what the programmer sees'.


    > From: Fred Cisin

    > There are more than a hundred different parameters involved. There is
    > no definitive agreement as to which parameter is to be used for the
    > classification, nor even which parameterS. ... a product that has one
    > classification by one parameter, and a different classification by
    > another parameter, there will be disputed classifications, since
    > different parameters are more or less important to each viewer.

And this too.

(Which is why, for the 68K, I listed several of the main user-visible
parameters, and noted that they were all 32 bits.)

	Noel


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