Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!shadooby!oxtrap!mudos!Marc.Unangst
From: mju@mudos.ann-arbor.mi.us (Marc Unangst)
Sender: ufgate@mudos.ann-arbor.mi.us (newsout1.26)
Newsgroups: comp.os.minix
Subject: Re: dosread.c again
Message-ID: <696.2543BDEC@mudos.ann-arbor.mi.us>
Date: Mon, 23 Oct 89 14:42:01 EDT
Organization: FidoNet node 1:120/129.0 - Starship Enterprise, Ann Arbor MI

In article <3768@ast.cs.vu.nl>, ast@cs.vu.nl (Andy Tanenbaum) writes:
 > 1. Large model.  A real ugly hack forced by the brain damaged Intel
 >    architecture.  MINIX doesn't inherently have an 64K limit.  On the
 >    Atari you can have programs as large as physical memory.  I expect
 >    the arrival of the 386SX will spell the end of the 8088 and 80286
 >    within a couple of years.  At that point we can adopt a single linear
 >    32-bit address space, like MINIX-ST.

My point is about the here-and-now, not some distant point down the road.
Despite the fact that I really like having an OS with full source and
all that (hell, I *like* to hack), I'd also like to be able to use MINIX
for "real" things, too, like reading news, or running a BBS.  I only have
a V20 machine now, and that's why I'm running MINIX.  If I had a 386SX,
I'd be running Xenix/386 (or some other version of 386 Unix), not MINIX.

 > 2. Virtual memory.  I tend to regard this as obsolete.  With Bruce Evans'
 >    protected mode kernel and a 2M 386 you can have up to 2M of programs
 >    running at once.  That has to be enough for a personal computer.
 >    Thus I see virtual memory as something with a lifespan limited to
 >    the older machines, which will probably be gone in a couple of years.

As I said previously, I don't *have* a 386.  If I did, I'd be running
Bruce Evans's protected mode kernel.  However, virtual memory has been
around since Unix on the PDP-11, so I don't think it's too much to ask
for it to be present on an 8088 Unix.

 > 4. UUCP.  I believe Peter Housel posted something along this line (uupc).

Okay; I've never seen this -- I'll have to go hunting on bugs.nosc.mil.

 > 7. Boot off hard disk. I suppose it is possible, but a low priority item.
 >    Many people still use DOS and want to have the hard disk boot start DOS.
 >    You can't have it both ways.

Well, there are several ways you can do this:

        1. Make up a special "MINIX boot floppy" that just jumps to the
           boot track on the MINIX root partition, and boots from there.
           You use this floppy when you want to boot MINIX; although you
           still have to get the floppy out, the actual boot process
           occurs on the hard disk.
        2. Use FDISK to switch around the default boot partition whenever
           you want to boot MINIX.
        3. Have MINIX offer a "boot to DOS" option, where it just restarts
           and boots off the partition of your choice.  I believe that
           SCO Xenix does something similar to this, and this is probably
           the most elegant way of handling it.

 > 9. A format program.  I'd love it.  Any volunteers?

Maybe I'll give it a whack after I upgrade to 1.3d and get all of my
favorite patches/ugprades installed.  Who knows; by then, someone else
may have written it.

 >10. Backup.  There is no dump/restore, but I wrote a program called backup.c
 >    and posted it.  I use it all the time and find it quite adequate.
 >    You give it the name of a directory and put a floppy in the drive, and
 >    it looks for files that have changed since the last backup and saves them
 >    all.  I even have a shell script that calls the program with the right
 >    flags (which I posted).

Yeah, I saw your backup.c.  While it's perfectly fine for backing up a
few files (those that fit on one floppy), it's not good for backing up
your whole hard disk or something.  I have a version of PDTAR, which
supports multi-volume archives, so this isn't so bad...Still, it would
be nice to have something other than tar.

 >  Item                          DOS     MINIX
 > 4. UUCP                        No      Yes

Actually, DOS has at least four UUCP implimentations I can think of.  UUPC,
UFGATE, PC-MAIL, and UUMAIL.

 > 5. Mail                        No      No (except local mail)

Again, with the addition of one of the above UUCP programs, you can do
UUCP/Internet mail.

You say the score is 4 to 4.  I pretty much agree -- MINIX makes up 
for its (many) lacking qualities by being closer to Unix than DOS is
(and probably the closest I'll ever get on this machine).  I'll 
still use MINIX, and I'll still use DOS, but those additions would
make me use MINIX almost exclusively.

--
Marc Unangst
Internet: mju@mudos.ann-arbor.mi.us
UUCP    : ...!uunet!sharkey!mudos!mju
Fidonet : Marc Unangst of 1:120/129.0
BBS     : The Starship Enterprise, 1200/2400 bps, +1 313-665-2832