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From: ast@botter.UUCP
Newsgroups: comp.os.minix
Subject: Re: Future Patches To Make Minix Usable in the Real World
Message-ID: <1205@botter.cs.vu.nl>
Date: Wed, 10-Jun-87 05:15:21 EDT
Article-I.D.: botter.1205
Posted: Wed Jun 10 05:15:21 1987
Date-Received: Sun, 14-Jun-87 20:38:08 EDT
References: <114@jc3b21.UUCP>
Reply-To: ast@cs.vu.nl (Andy Tanenbaum)
Organization: VU Informatica, Amsterdam
Lines: 57

In article <114@jc3b21.UUCP> gordon@jc3b21.UUCP (R. Gordon Price) writes:
>There are some glaring problems with using MINIX...

Most of the problems are caused by my desire to make the system run with a
256K 1 floppy disk system, and run reasonably well with a 640K 2 floppy disk
system.  In other words, I do not assume that people have a hard disk.  Why?
A recent survey in a local computer hobby magazine showed that only 5% of
the readers had a hard disk.  95% worked with floppy only.  In my own dept.
I know that very few students have hard disks, and even among the faculty
members here who have a computer at home, I believe that I am the only one
with a hard disk.  Obviously for a corporation $500 more or less for a PC
doesn't make much difference (unless, like American Airlines just did, the
corporation orders 8000 at a time, in which case the issue is at least worth
thinking about).  For students who have to borrow money from the bank to pay
their tuition and have to eat at the university cafeteria 3 times a day 
because that is all they can afford, acquisition of a hard disk is a major
purchase that has to be weighed against other ways to spend money.  As time
goes on and hard disks get cheaper, this issue becomes less critical and the
situation may change.  For the time being, I don't want to ignore these
people, as all the other UNIX systems have done.

Your specific comments:

1) No floats.  I agree, they would be nice, but I haven't personally used
   a number > 32767 in years.  Is anyone working on floats?

2) Who would ever try to run MINIX on floppies??  Poor people.

3) Multiuser.  See Andrew Valencia's posting of last week for multiuser.

4) The / directory is a flying joke.   Every system works poorly when the disk
   is full.  Most users work in /usr/something not /.  Again, with floppies only,
   space is definitely cramped.

5) RAM disk is dumb.  On a floppy system it is critical.  360K is too small for
   bin, but 240K RAM disk + 360K just makes it (barely), leaving the second
   floppy for user files.

6) No swapping.  Ever try swapping to a floppy?  I did.  The first version of
   MINIX did just that.  To make a long story short, it didn't work real good.
   It was a lot of code, so I threw it away.

7) 640K limit.  The 8088 arhcitecture does not encourage use of memory above
   640K, but a RAM disk driver for extra memory shouldn't be too hard.

8) Booting from hard disk.  This fix has been posted, but I don't like it.
   First of all, you lose hard/floppy compatibility.  Second, if your hard
   disk ever gets flakey, you can't do anything.

9) FSCK should be renamed "Fragment,Crash,Collate,Kill".  You are
   not supposed to fsck device 0, only 1-4.  Device 0 is the raw disk.

MINIX is being ported to the 68000 (Atari ST), but again we are assuming that
some users (probably most users) have floppy only, and the system will be
designed for that.

Andy Tanenbaum (ast@cs.vu.nl)