Re: [TUHS] Interesting commentary on Unix from Multicians.

["Greg A. Woods" <woods@robohack.ca>]

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At Fri, 8 Apr 2022 17:34:27 -0600, Andrew Warkentin <andreww591@gmail.com> wrote:
Subject: Re: [TUHS] Interesting commentary on Unix from Multicians.
>
> I think it's useful to have both I/O and memory views for files.
> Things like commands that work equally well whether stdout is a disk
> file or something like a pipe wouldn't work so well in a system where
> disk files can only be accessed through a memory-like interface.
> However, I guess the I/O interface could just be implemented with
> library functions rather than real I/O syscalls for disk-like files.

I/O is good for I/O of course (e.g. to devices, like terminals and
printers and such), and if you can "attach" that I/O to a segment, or to
another program's I/O, all the better:

    https://multicians.org/myths.html#nofile

(One big complication forced by hardware limitations of the day was
rather limited file (i.e. segment) size, and thus Multics developers
invented multi-segment files, and as mentioned in that link, stream
access to them was often through the I/O mechanism, but of course this
was a simulation done by copying (I think) data from a mapped segment of
the file to a buffer in a heap segment.)

--
					Greg A. Woods <gwoods@acm.org>

Kelowna, BC     +1 250 762-7675           RoboHack <woods@robohack.ca>
Planix, Inc. <woods@planix.com>     Avoncote Farms <woods@avoncote.ca>

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