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From: mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga: Which replacment OS?/UN*X ??
Message-ID: <4237@jade.BERKELEY.EDU>
Date: Fri, 3-Jul-87 02:29:06 EDT
Article-I.D.: jade.4237
Posted: Fri Jul  3 02:29:06 1987
Date-Received: Sat, 4-Jul-87 12:59:23 EDT
References: <600@gryphon.CTS.COM> <1705@vdsvax.steinmetz.UUCP> <1576@stb.UUCP> <3979@jade.BERKELEY.EDU> <214@sugar.UUCP>
Sender: usenet@jade.BERKELEY.EDU
Reply-To: mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer)
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In article <214@sugar.UUCP> peter@sugar.UUCP (Peter DaSilva) writes:
<Well, la-de-da. Most UNIX systems don't support bit-mapped displays and
<windows at all, and I belong to the unprivileged masses who have never used
<such a beast.

Of course, you're ignoring that the terminal emulator that I mentioned
which ran on anything which was more than a glass TTY that you could
write a termcap entry for. Naturally there are more terminal emulators
for bitmapped displays than for terminals. After all, why emulate a
terminal if you've already got one?

<> And the original point still stands. For some reason, Unix modem
<> programs don't get very good throughput. Nuts - Unix terminals don't
<> get very good throughput. My CP/M-68K system came closer to pushing
<> 9600 baud out it's serial port than Unix does.
<
<We get 19200 and even 38400 out of the Unisys 5000 at work... and it's only got
<2 68000s to serve typically 15-25 users. It's frowned upon, but it's possible.

So? I can set unix serial lines to 19200 and 38400, and they sure go
faster than the same lines set to 9600. But the "9600 baud" lines
aren't going 9600 baud, and the 1200 baud lines aren't going 1200
baud. If you stack your 38400 serial lines next to something simple
generating 38400, and they actually go the same speed, then you've got
a point.

<> I use single-user Unix systems all the time, with little or nothing in
<> crontab. They swap quite a bit, too (something about *large* window
<> managers and tools).
<
<Once again, most small UNIX systems don't have gross window managers and
<tools.

But we're talking about what to put on a system with a bitmapped
display and a mouse. If it don't got a window manager & tools, forget
it. I might as well by a Stride & a z39. So how many small Unix
systems with bitmapped displace and rodents don't have gross window
managers and tools (like X, or Suntools, or NeWS)?

Of course, it doesn't take much *without* the window manager to make an
Amiga class machine running Unix (even something as small as v7) go
into agonies. Get a Fortune 32:16 with 1/2 meg, and try running
Unipress Emacs on it.

<> The multitasking analogy isn't quite right. Multitasking gives you
<> some basic abilities you didn't have before. Swapping just means you
<> get to run more and bigger applications before you run out of memory.
<
<That is a new basic ability: the ability to ignore memory limitations
<to a great extent.

No, it doesn't. Any single application must still be smaller than
physical memory. So any application that runs on your swapping system
will almost certainly run on a non-swapping system. If you'd been
arguing about virtual memory instead of swapping, your initial
assumption (the ability to ignore memory limitations) would have been
true. But the conclusion is still false.

The ability to ignore memory limitation just leads to lots of
programmers who ignore memory limitations.  The result is usually
larger, slower code to do the same thing that a non-vm system would
do, and enormous code with lots-and-lots of features.

There are programmers - and programming environments - that can really
benefit from vm. But they tend to be few and far between, and capable
of doing things with small memories that are beyond mere mortals and
simple programming environments.

<Of course swapping on the Amiga is a pretty problematical thing... and, also
<of course, nobody says that AmigaUNIX has to support it. Minix doesn't, for
<example, and it's a pretty close implementation of V7 UNIX.

Right, an Amiga unix port doesn't have to swap. But if you throw out
the nifty message-passing exec for the unix monolithic monitor, I
don't really want the result. The Minix approach is much better. Build
a good OS, using what the last 15 years have taught us about OS
design, and put libraries on top of that to emulate Unix.

<I often want to "swap" deluxe paint to disk while I run
<something else. Gobs of memory would do as well, but I don't have it.

So the Unix approach to high performance (throw resources at it until
it's fast) would work on the Amiga. But that works on anything.

	<mike
--
ICUROK2C, ICUROK2.				Mike Meyer
ICUROK2C, ICWR2.				mwm@berkeley.edu
URAQT, I WANT U2.				ucbvax!mwm
OO2EZ, I WANT U2.				mwm@ucbjade.BITNET