[Info-vax] Chinese Alpha?

[Arne Vajhøj]

On 5/3/2012 4:09 PM, glen herrmannsfeldt wrote:
> Bob Koehler<koehler at eisner.nospam.encompasserve.org>  wrote:
>
> (snip)
>>    8086 inherits archiecture lessons from the 4 bit 4004 via the 8 bit
>>    8008.  But current IA32 inherits actual instructions from 8086.  8 bit
>>    register instructions were part of the 32 bit 80386 and and 486, and
>>    I think they are still supported.
>
> The 8086 inherits instructions from the 8080, but the actual opcodes
> have changed. You can map the 8080 registers onto the appropriate
> 8086 registers, and rewrite assembly source using new assembly
> opcodes, assemble the result, and run it.
>
>>    Alpha inherits lessons learned from 16 bit PDP-11, 32 bit VAX, and
>>    36 bit PDP-10.  I suspect there are lessons learned from other PDP
>>    and I think I see a few things from IBM 360.  But it does not inherit
>>    instructions from any of those processors.
>
> I think I believe that. Without going through them one at a
> time, though, I wouldn't be so sure that there weren't any.
>
> Using only 32 and 64 bit load/store made it pretty different
> from the previous processors.

I would think that x86-64 is similar to x86 in somewhat
the same way as VAX was similar to PDP-11.

Alpha and VAX do not really share any characteristics. All
the VAX specific stuff was done as PALcode.

Arne