From: Dave Horsfall <dave@horsfall.org>
To: The Eunuchs Hysterical Society <tuhs@tuhs.org>
Subject: [TUHS] Re: Clever code
Date: Tue, 13 Dec 2022 14:53:40 +1100 (EST) [thread overview]
Message-ID: <alpine.BSF.2.21.9999.2212131444030.1473@aneurin.horsfall.org> (raw)
In-Reply-To: <CAMYpm85A7ACZ1mYRjrKDNNRVPh-wnZVXAN=bkjr6FXHeeM2suw@mail.gmail.com>
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On Tue, 13 Dec 2022, Rudi Blom wrote:
> I vaguely remember having read here about 'clever code' which took into
> account the time a magnetic drum needed to rotate in order to optimise
> access.
Sounds like you're referring to SOAP (Symbolic Optimal Assembly Program)
on the IBM 650; the programmer wrote the code "straight down" and SOAP
reordered it for rotational latency.
> Similarly I can imagine that with resource restraints you sometimes need to
> be clever in order to get your program to fit. Of course, any such
> cleverness needs extra documentation.
Try writing a bootstrap program in 512 bytes :-) Self-modifying code was
the order of the day...
> I only ever programmed in user space but even then without lots of comment
> in my code I may already start wondering what I did after only a few months
> past.
You could be clever in kernel space too, such as taking advantage of
the DATIP/DATO cycles on DEC's Unibus when updating a memory word i.e.
read/modify/write.
-- Dave
next prev parent reply other threads:[~2022-12-13 3:53 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-13 3:30 Rudi Blom
2022-12-13 3:41 ` Warner Losh
2022-12-13 3:53 ` Dave Horsfall [this message]
2022-12-13 4:03 ` George Michaelson
2022-12-13 8:05 ` Ralph Corderoy
2022-12-13 9:45 ` Dagobert Michelsen
2022-12-13 7:47 ` Ralph Corderoy
2022-12-13 19:56 ` Dave Horsfall
2022-12-13 11:46 ` John P. Linderman
2022-12-13 14:07 ` Douglas McIlroy
2022-12-13 14:31 ` arnold
2022-12-13 14:48 ` Ralph Corderoy
2022-12-13 15:10 ` Douglas McIlroy
2022-12-13 15:34 ` Stuff Received
2022-12-13 15:56 ` Ralph Corderoy
2022-12-13 23:02 ` Harald Arnesen
2022-12-14 7:31 ` arnold
2022-12-15 18:06 ` Marc Donner
2022-12-15 18:08 ` Marc Donner
2022-12-15 6:30 ` [TUHS] Delay line memory (was: Clever code) Greg 'groggy' Lehey
2022-12-13 15:52 ` [TUHS] Re: Clever code Bakul Shah
2022-12-13 16:14 ` Ralph Corderoy
2022-12-13 16:30 ` Bakul Shah
2022-12-15 6:39 ` [TUHS] Sector interleaving (was: Clever code) Greg 'groggy' Lehey
-- strict thread matches above, loose matches on Subject: below --
2022-12-13 18:02 [TUHS] Re: Clever code Noel Chiappa
2022-12-13 17:58 Noel Chiappa
2022-12-13 18:51 ` G. Branden Robinson
2022-12-13 20:14 ` segaloco via TUHS
2022-12-13 20:58 ` Warren Toomey via TUHS
2022-12-14 2:28 ` Luther Johnson
2022-12-11 20:03 [TUHS] Re: Stdin Redirect in Cu History/Alternatives? Larry McVoy
2022-12-12 2:15 ` [TUHS] Clever code (was " Bakul Shah
2022-12-12 9:48 ` [TUHS] Re: Clever code Michael Kjörling
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