80186 and now AMY chip

From: Eric J. Korpela <korpela_at_ellie.ssl.berkeley.edu>
Date: Wed Nov 22 11:45:09 2000

> Try asking programmers what width processors are instead of hardware
> engineers. They'll tell you that the 8080 and Z-80 are 8-bitters,
> and that the 68000 and IBM 360 (most models) are 32-bitters.

Nope, any programmer who cares how fast their code runs will let you
know that the 68000 is a 16 bitter. It's not like I've never coded
for 68K. I certainly prefer it to intel. That doesn't make it
32 bit.

> > No, every x86 chip since the original 386 is a 32 bit CPU since
> > the width of the integer ALU is 32 bits.
>
> Actually there is a 64-bit integer ALU in most recent x86 processors.
> Describing where it is and what it does is left as an exercise to
> the reader.

Are you talking about the use of the floating point unit for integer
multiplies and the addition of MMX/SSE stuff? I don't think that
qualifies. The bulk of integer operations are still done 32 bits at
a time.

> The reality is that there is no single "correct" measure of the
> "bitness" of a processor.

Ok, I'll admit that.

Eric
Received on Wed Nov 22 2000 - 11:45:09 GMT