On Fri 10 Jul 2015 at 09:33:56 +0000, [email protected] 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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