[Simh] VAX vectors

[Rhialto]

On Fri 10 Jul 2015 at 09:33:56 +0000, lists at openmailbox.org wrote:
> I think you could argue at the beginning System/360 did have things in
> common with what would later be called RISC although z/Architecture has
> overshadowed a lot of that RISC flavor in favor of more specialized
> instructions and addressing modes.

I recall reading that the whole RISC thing was more or less started with
compiler writes for the 360 noticin that in practice they only used a
rather limited subset of the available instructions. That got developed
in hardware in the POWER cpu and later in the POWERPC (PPC).

I did program on the 370 for a semester in uni, and it was after a
semester of pdp11. I really hated the 370, it was so horrible. There
were no relative addressing modes with offset more than 12 bits. And
even  in the 64-bit z/System there isn't, apparently... and each
instruction has its own different subset of addressing modes it works
with.

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert  -- The Doctor: No, 'eureka' is Greek for
\X/ rhialto/at/xs4all.nl    -- 'this bath is too hot.'
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