Hacker News Reader

Comment by beat | Hacker News Reader

They kept that trick up for a long time. As of AIX 3.2.5 back in the 1990s, an "idle" RS/6000 ran 70% cpu utilization. They were super-fast and efficient in their day, too.

Dunno how true that is today, but I wouldn't be surprised if AIX still uses the same kind of tight event loop internally.

View on HN

RS/6000. Heh - I'm the only person left in my state who still knows how one of these works.

Diagnosing startup problems with all those super quick flashing codes was a nightmare.

Yeah, but SMIT is still the best old-school admin tool ever.

Back in the day, I considered doing an open-source knockoff, just to call it SMUT.

http://www.pimpworks.org/ibm/aixled.html

:-)

http://ps-2.kev009.com/rs6000/ - some fun stuff here

I played with one for a few years, felt pretty l33t dd'ing the kernel into the prep partition rather than using yaboot.

Presumably these were the pre-PowerPC machines?

I think John Cocke was working out the architecture of that line then. He's not often credited with it but he invented RISC with that effort. Hardware was built in research (called the 80x where I don't remember x) but the actual Power-PC was quite a ways in the future.

http://en.wikipedia.org/wiki/IBM_801

To me the brilliance in Radin's 801 paper was the belief that you could trust the compiler to do a better job. Essentially a compiler can have more than 10 fingers to find its way through optimizing code (optimizing assembly often means marking places with your fingers and glancing back and forth as your trace the logic of execution). That realization struck me at the time like a thunderbolt.

Cocke deserved his Turing, no question about it, however I see the intellectual antecedents of RISC being machines like Gordon Bell's PDP-6/10 (with a small, clean, orthogonal instruction set) and Cray's 6600 (with its overlapping execution units). CISC was a doomed effort to make assembly programmers more efficient.

Through the most popular compiler output today is a CISC instruction set, that output is simply run on microprogrammed emulators.

Yes, John and Fran Allen wrote the first optimizing fortran compiler and developed most of the optimization techniques and analysis used by subsequent compilers.

I knew John and it was that work that led him to design an instruction set optimized for compilers that was implemented in the 801. I'm less aware of George's contribution. Perhaps you could enlighten me.

I was simply referring to to famous 801 paper in the IBM R&D Journal of which Radin was the author.

Reply on news.ycombinator.com