Path: news.cs.umb.edu!hsdndev!wupost!uunet!olivea!isc-br!bunker!nuconvex!aminet!barrett
   From: barrett@aminet.uucp (Keith Barrett)
   Newsgroups: misc.forsale.computers,ne.forsale
   Date: 18 Jul 92 00:52:42 GMT
   References: <CIAMAC.92Jul13132631@picadilly.media.mit.edu>
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   Reply-To: barrett%aminet@nuconvex.com
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   Organization: Waterbury USENET/UUCP
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   X-Copyright: (c) 1992 Keith Barrett; May be distributed freely, Not for sale
   X-Disclaimer: Statements expressed are not representitive of any employer
   X-NewsSoftware: XRN V6.17 Amiga UNIX SVR4

   I apologize in advance for this, but this makes no sense:

   In article <CIAMAC.92Jul13132631@picadilly.media.mit.edu>, ciamac@picadilly.media.mit.edu (Ciamac Moallemi) writes:
   >
   >AT&T Unix PC for sale -
   >	1 MB Memory
   >	20 MB Hard Drive
   >	5.25 in Floppy
   >	1200 Baud Modem
   >	Full Manual Set
   >	Tons of Extra Software Pre-Loaded
   >
   >A great home unix box.  $300 or best offer.

   UNIX requires an absolute minimum of about 60 meg disk, and about 3-5 meg
   of memory. Plus it would take a lot of 5.25" floppies. There is no way this
   system could ever have supported UNIX. Am I missing something here?

You are missing facts and history.

The UNIX PC's have dynamically linked libraries, which is one reason
why they can use less disk space than classical bloated unix systems.
Not to mention that System V comes with so little functionality
compared to Berkeley unix that not much space is needed. Still, these
things do fine for minor C development and we even painfully taught
graphics on them, using uucp to our Sun network to support printing
and mail. If I'm not mistaken, most gnu tools will run on them (not
hard, since they have a 68010 processor).

Here's our UPC guru's reply to my query about address space and
whether the UPC did dynamic linking:

    Date: Tue, 21 Jul 1992 22:14:10 -0400
    From: eoneil@ra.cs.umb.edu (Betty O'Neil)
    To: ram@cs.umb.edu
    Subject: Re:  UNIX PC's

    Yes, both for dev drivers and shared libraries.  The 4th M of 4 M
    of VM is used for this.  The kernel is in the first .5 M, the user
    image in the 2.5M in the middle.  The video ram, PT, i/o regs are
    all above that in the address space.  This is all about UNIX on the
    UPC, of course.  20Mb however is a common disk size, not clearly 
    related to all this.--Betty


Note also that Version 6 and 7 unix all fit happily on much smaller
machines. In 1978 we ran unix on a PDP11 which had 256kB of memory and
two 5mB disks. The machine stood in a 6 foot high 19" rack, somewhat
bigger than our Sun 4/490 with 3gB of disk, 64mB of memory and a tape
drive. It supported 8 logins and tolerated 2-3 compilations or 2-3
active emacs's running (Can you old-timers say "Teleray 1061"? Gee
whiz, that thing is still in the termcap file! No _wonder_ unix is so
big. It's whole history is written in all its support files. If I look
hard enough will I find directories named "ken" and "dmr" in the
kernel string tables?)

As to the UPC's we found the drive's to be somewhat unreliable, but
generally replacable for around $25-40 (we recently bought some at Eli
Hefron).

Betty ported Xinu to these machines, the boards from which we now use
as standalone Xinu machines for OS courses. You can get her source
code with anonymous ftp to ftp.cs.umb.edu in directory /pub/xinu7300

A bit more history: AT&T originally tried to sell these machines for
about $4000(?) in 1986(?). They ended up donating a ton of them to
universities. For example, at that time we made a grant proposal to
AT&T for 10 3B2/400 machines--approximately a Sun3 class machine with
a BLIT terminal---and were awarded 8 3B2's and ___40___ Unix PC's (we
didn't ask for _any_). This was a common experience. About the same
time, the street price for them was about $900, so I suppose AT&T
couldn't even give them all away. The hardware was made by Convergent
Technologies, reasonably competently.


Bob Morris
ram@cs.umb.edu