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

Chuck Guzis cclist at
Fri Sep 16 18:41:56 CDT 2016

On 09/16/2016 03:20 PM, Jecel Assumpcao Jr. wrote:

> Note that in the conclusion to this 1979 article, the Motorola
> engineers say "It is a 32-bit architecture that supports many data
> types and data addresses."

Unfortunately, that doesn't clear the picture any.

What would you call a Packard-Bell PB250, with its bit-serial ALU and
delay line memory?  It had a 22 bit word, with addressing granularity to
match.  So it's a 22-bit architecture?

The TMS9900 has already been identified as a 16-bit ISA, even with its
bit-serial ALU.

So some enterprising soul could device a shift-register-based MPU with
1-bit memory bus, but with a 256 bit word size and it would be a 256 bit

Now you understand my "Alice Through the Looking-Glass" quote.


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