Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cbmvax!jesup
From: jesup@cbmvax.commodore.com (Randell Jesup)
Newsgroups: comp.arch
Subject: Re: Personal OS
Message-ID: <11875@cbmvax.commodore.com>
Date: 28 May 90 05:42:40 GMT
References: <402@newave.UUCP> <3300131@m.cs.uiuc.edu> <9437@pt.cs.cmu.edu>
Reply-To: jesup@cbmvax (Randell Jesup)
Organization: Commodore, West Chester, PA
Lines: 46

In article <9437@pt.cs.cmu.edu> lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) writes:
>  Plus, that
>famous "bloat" leaves me with 65 processes on my workstation as I
>type.  Don't ask me what they all do.  Do I trust that they are all
>debugged?  Hah! I KNOW that some of them aren't, and I don't trust
>the rest.  Nor do I want the nightmare of making "easy modifications"
>to these intricate, hard-to-test things.  Is this "golden age" going
>to simplify them, going to reduce this bloat?  Would you like to buy
>this bridge I own in Brooklyn?
>
>In summary: if my workstation had a single address space, I'd sell it
>and buy something adequate.  (Sorry, Ed.)

	Sure, every one here (or their company) can afford full-blown
workstations, but not everyone can.  The speed issues you blew off do still
exist: an Amiga 3000 or 2500/030 running AmigaDos is a hell of a lot
snappier than the same machine running SysV Rel4.  For less capable machines,
like 68000-based ones (A2000HD, A500), running anything with more overhead
would be VERY painful (I know, I have a Sun-2).  :-(  Human-factors
research indicates that if response time is more than a very small value
(a few tenths of a second, I think), productivity drops considerably.  So
keeping a "snappy" feel to a machine (both interface and actual applications)
is quite important.

	Second, remember that 'single address space' and protection (and VM)
are all separate issues, especially on a single-user machine.  A single
address space is VERY useful in speeding up interactions between pieces of
software, and simplifying the writing of multi-threaded programs (think of
why threads have become popular).

	The Amiga FS (as has been mentioned here) is fast, even when compared
to much larger and faster machines.  (With cheap, small, 40 MB quantums Amigas
can easily hit 700K/s through the filesystem (largely disk rotation limited)).
The single address space makes this easier to achieve.

	Note: I'm not arguing for Lambert's OS proposal, just over a few of
the items on the list.  Nor do I say the AmigsOS is perfect; it's far from it.
However, it's pretty well-adapted to the marketplace and hardware it's aimed
at.  The challenge is in adapting it to more powerful hardware without losing
the strengths it has.  AmigaDos 2.0 (and the A3000) is a big step in that
direction.

-- 
Randell Jesup, Keeper of AmigaDos, Commodore Engineering.
{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.cbm.commodore.com  BIX: rjesup  
Common phrase heard at Amiga Devcon '89: "It's in there!"