And speaking of ALGOL
Paul Koning
paulkoning at comcast.net
Tue Aug 11 12:59:28 CDT 2015
> On Aug 11, 2015, at 12:20 PM, Chuck Guzis <cclist at sydex.com> wrote:
>
> ...
>> I suspect part of the reason is that Algol wasn’t all that popular in
>> the USA even if its heyday. Add to that the fact that most computer
>> designers weren’t all that skilled in software. And finally, as the
>> RISC experience has shown, it isn’t really worth it.
> ...
> What RISC does demand is a fast memory system. The 6600 had 1 usec memory interleaved 10 ways, so it could issue a read or write every machine cycle (100 nsec). Without that, the 6600 could well have been a real dog.
Every machine needs a fast memory system. CISC machines just as much, after all the number of memory references per operation of a given kind doesn’t depend on the sort of CPU architecture you use. All that changes is whether the cycles are issued by regular machine code, or micro-engine actions.
A full-up 6600 is 32 way interleaved; half size you get 16 way interleaving. Once nice benefit is that context switching takes only a few microseconds, because the exchange jump would swap current and new context at memory speed: 16 words issued at 100 ns intervals once the operation gets moving.
paul
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