Re: ancient OS history, ARM is sort of channeling the IBM 360

Lawrence D'Oliveiro wrote:

On Sat, 29 Jun 2024 18:22:04 -0000 (UTC), John Levine wrote:
 

... more often than not locate I/O is faster and easier.

 
Given all the caveats and restrictions, “easier” is not how I would
describe it.

Again, it depends.  For COBOL, you didn't have to specify anything.
The compiler set up everything for you for you, and it "just worked".

 
But perhaps we’re talking at cross-purposes. If Mitch did his TSS and
PL/I stuff in the 1970s, while you’re talking about the 1960s, then
that could explain it. By the 1970s, CPU/RAM speeds had improved to
the point where copying records a few hundred bytes at a time between
buffers was not the performance bottleneck; disk I/O was.

Yes, but given multiprogramming, even in the 1970s, you would typically
have several batch programs running at the same time, so during waits
for I/O, another program could use the CPU.  But using the CPU to move
records meant it couldn't be doing anything else at the same time.



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 - Stephen Fuld
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