[Info-vax] OT: IA-128 ???

[Arne Vajhøj]

Neil Rieck wrote:
> I hope you guys are correct that this phrase represents a MS s/w
> project. However, the use of the phrase IA-128 makes me wonder if
> we've seen a glimpse of something coming from Intel.
> 
> JF:
> 
> Way back in the early 1980's, a DEC instructor told the class that
> processor bit size was related to the programmer's view of the general
> purpose registers. For example, even though the 8088 had an 8-bit
> memory buss, it was (internally speaking) a 16-bit processor. Even
> though the 6502 had a few instructions that treated two 8-bit
> registers as a 16-bit pair, it was an 8-bit processor.
> 
> Obviously things changed when AMD invented AMD64
> http://en.wikipedia.org/wiki/AMD64
> which forced Intel to respond in kind with similar 64-bit extensions
> (a true 64-bit extension of the GP regs) called x86-64 and/or IA-64.
> 
> I'm not saying that this is Intel's intention, but Intel could develop
> a CPU with 128-bit regs without changing the buss interface unit
> (BIU).

The general accepted definition of a X bit computer is the size
of addresses not the size of registers.

There are good practical reasons why they often are identical,
but they do not have to be.

Even a VAX has somewhat 64 bit general register because q operations
could use Rn and Rn+1.

Arne