Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!decvax!decwrl!pyramid!ut-sally!std-unix
From: std-unix@ut-sally.UUCP
Newsgroups: mod.std.unix
Subject: Re: Job Control
Message-ID: <6051@ut-sally.UUCP>
Date: Mon, 20-Oct-86 05:26:04 EDT
Article-I.D.: ut-sally.6051
Posted: Mon Oct 20 05:26:04 1986
Date-Received: Mon, 20-Oct-86 21:42:07 EDT
Organization: IEEE P1003 Portable Operating System for Computer Environments Committee
Lines: 51
Approved: jsq@sally.utexas.edu

From: pyramid!allegra!cbosg!osu-eddie!bgsuvax!schaefer (Stephen Schaefer)
Date: Thu, 16 Oct 86 13:05:33 edt

I'd like to offer some observations from my experience concerning
windows.  I am very comfortable using the wm window manager (by Robert
Jacob, enhanced by Matt Lennon and Tom Truscott).  The present design
relies heavily on pty's and the 'select' call of 4.[23]BSD.  I use a
9600 baud line with a 24*80 screen, which is quite sufficient.  I feel
no need at all for bit-mapping until I want to draw pictures, or
preview some typesetting, which has nothing to do with windows.  I'm
guessing that it takes about half a second to repaint my screen - the
same amount of time as vi takes to show the next screen full.  Far more
often, the window simply scrolls.
	I had a chance to work with a 5620 for a while.  While I was
directly connected at 9600 baud to a 4.2BSD 11-780, I told it to act
like a VT100 with a 70*88 screen.  I was more than happy - for
editing, I used the whole screen, for shell interaction I used a half
screen to cut down on update time, and because I'm usually working on
a minimum of two things at once.  Ghosting of the phosphor was far
more of a problem than speed.  I also used the 5620 with a 3B2, shell
layers, and a mouse.  Pulling windows around was fun for a while, but
it never became important to me, the way switching from window to
window has.  The bit mapping was good for drawing pictures and
previewing typesetting, but I never saw what it had to do with
windows.
	I haven't mentioned job control yet - I use it when it's
available.  I very often want a process to freeze until I find it
convenient to get back to it.  I am willing to entertain the
possibility that windows could take over much of that function, but
when I suspend, I am usually thinking "suspend", and it would take
some thought (or re-conditioning) to consider switching windows.  A
second consideration is that I use GNU emacs, and it significantly
faster to ^Z and fg than to quit and restart.  I don't understand the
accusations that ^Z is a "kluge", unless these people are referring to
the implementation, which I haven't studied.  It was utterly clear,
from the first time someone showed it to me: hit ^Z, ask to see your
jobs, now choose how or if to continue them (in foreground or
background), but be assured that they are still there until you
dispose of them.  I survive without it when I don't have it, but I use
it when I do have it.
	In sum: windows are good for multitasking *me*, and appear to
depend on pty's and maybe select(2).  Bitmapping is good for pictures,
but is irrelevant to a purely text environment - which is where I am
almost entirely.  Job control is good for suspending processes, and is
nice for avoiding the load time of large programs.  The three are
independent facilities.  An expensive, full-featured system would have
all of them.  Less expensive systems could be missing one or more of
them and still be Un*x.  If I had to choose the most valuable one it
would be pty's, but that is probably just my taste.

Volume-Number: Volume 7, Number 74