Contents | < Browse | Browse >
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Have Two Amigas?  ParNET 'Em!                     Philip A. Vedovatti %%
%%                                             vedovatt@u.washington.edu %%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Like many Amiga users, last year I upgraded my system from an Amiga
500 to an AGA machine, the A4000.  Having put a fair amount of money into
my old system (an '030 accelerator, hard drive and so on), I decided
to keep it so I could run old demos and play games on it.  As most A500
owners know, even today it's quite a functional machine.  However, the
500 somehow ended up packed in its original box, under my bed.  Maybe
it was lack of desk space at the time, or just my excitement of using
the A4000, but the 500 just wasn't getting any use.

I started to miss some of the old programs that would only run on my
500, so I pulled out the old machine and set it up.  I had moved to a
new city and had a little more desk space, so the A4000's little brother
got its place next to the other machine.  The A500's hard drive had lots
of music files, IFF images and other useful programs.  I thought there
must be a way I can hook these two machines together so I can access all
the goodies on the 500 from my 4000.  I didn't really want to spend a
lot of cash for networking hardware, and I didn't want a null modem setup
since you can only access the other machine through a terminal program.

Enter ParNET.  Back in 1988, Doug Walker and John Toebes of the Software
Distillery developed a software package to allow one to connect two Amigas
together using a modified cable that connects the two parallel ports.
Matt Dillon, of DNet fame, wrote the original parallel device for Parnet.
Since that time there have been several other programs developed to
utilize the Parnet connection, and I will talk about them later in this
article.  I decided to set up a ParNET network between my two Amigas a
few weeks ago.

THE CABLE -- MAKING THE CONNECTION
----------------------------------

To develop any kind of network, you need, of course, some kind of hardware
piece to connect the two machines together.  The ParNET cable is fairly
easy to make from a standard DB-25 printer cable if you have a little
knowlege in electronics, and a tester to make sure your connections are
correct.  I opted to do it the easy way and buy a cable.  There are
several sources for ParNET cables;  I ordered mine from Redmond Cable,
a reputable computer cable company.  The cost was $24 U.S., plus $3
for shipping.  Just ask for a ParNET cable, they'll know what you're
talking about.  The parallel port of the Amiga 1000 is different from
the other Amigas in that its port has a male connector, whereas the
other Amigas use a female connector.  A1000 owners will need either
a different cable, or an adaptor to make the cable fit.  Once you have
your cable, just connect each end of the cable to the parallel ports of
the two machines.  You will, obviously, have to disconnect any printers
connected to the machines if they use the parallel ports.  One word of
warning: Do NOT connect a standard parallel printer cable between your
Amigas.  You need to use a modified ParNET cable, or you may damage
your parallel port hardware.  Also make sure your machines are OFF
before disconnecting or connecting cables.

THE SOFTWARE -- Setting up the NET:
-----------------------------------

Obtaining the ParNET software is relatively easy.  The original ParNET
package is available on Fred Fish Library Disk number 400.  If you
get it from there, you will have to install all the files by hand.
There is a better solution, however.  Vernon Graner, formerly of
Commodore, put together an excellent installation package called
"ParBENCH", which uses the Commodore installer utility to put all
the files where they need to go, and set up the scripts for a point-
and-click network setup.  I highly recommend this package; it is
available on Aminet for Internet users, and several PD houses carry
it as well.  You will have to edit a script file called "ParNET-DriveList"
on each machine.  This file is used to tell the other machine what
devices are available, i.e. hard drive partitions and floppy drives.
Once you've installed everything, you're ready to go.  You should be
able to connect machines with different operating systems.  My A4000
is running Kickstart 3.0 while the A500 is running 2.04.  Lastly, if
you want icons to appear for the devices that you access on the network,
copy the file Node.rinfo to each partition.  If you want an icon for
the ramdisk you will have to copy it each time you power up.  You can
edit the network startup script to copy it automatically when you start
the network.

USING THE NETWORK -- Couldn't be easier!
----------------------------------------

To run the sofware after installing with ParBENCH, all you have to
do is click on the "Boot.Host" icon on one machine, and click on the
"Boot.Client" icon on the other machine.  It doesn't matter which is
the client or host, since the network is peer-to-peer; that is, each
machine can access files on the other without restriction.  Once you
have done that, a disk icon will appear on each machine with the volume
name of "Network".  If you know how to access drawers on the Workbench
(duh!) with the mouse, then you already know how to use the network.
Just double click on the Network icon, and you will see icons for each
of the devices on the other machine (if you have copied the Node.rinfo
file to each device).  You can delete, copy, transfer files, and run
programs just as if they were on the machine in front of you.

You can easily access the network from the shell as well.  The device
name for the network is NET: so if you want to access the ram disk
on the other machine, you type cd Net:ram (notice there is no trailing
colon.  ParNET accesses devices as if they were drawers).  To access
the Utilities drawer on the other machine, you would type:

cd Net:sys/utilities

If you are using OS 2.04 or higher, there are a few caveats.  When
using the shell, some commands do not work properly.  Most seriously
are the dir, list, and copy commands.  Never fear, there are several
fixes for this.  First, you can use some of the PD "list" or "ls"
commands instead, such as Nico Francois' "llist" which works quite
well.  An even better solution is getting a program called "NetPatch"
by Matthias Scheler which patches the system to allow you to use
the dir, list and copy commands normally.  I used NetPatch version 1.1
and it worked on both my 2.04 and 3.0 machines.  I have since added
a line in my Boot.Client and Boot.Host scripts to run this patch when
the network starts up.  There is another, newer ParNET filesystem
written by Olaf "Rhialto" Siebert floating around the nets, which
is supposed to fix the above problems as well.  It's called ParNFS.
Unfortunately, I couldn't get the setup script to make a valid connection
between the two machines.  Olaf, if you read this and you have any
solutions or updates, please e-mail me and I will pass the information
on to the readers.

OTHER GOODIES -- Adding further functionality to your network
-------------------------------------------------------------

Several authors have contributed useful utilities to enhance the power
of ParNET.  One of my favorites is MShell by Massimo Brogioni.  Essentially
what this does is allow you to type `rlogin' from your native shell, and
this starts up a remote shell.  Thus, anything you type in the window is
as if you were typing it FROM the other computer.  That means you can
run programs remotely on the other computer.  This has some very interesting
uses.  I like to use it to run a slideshow program on the other machine,
which works as a nice screenblanker as well when I don't need to look at
the monitor of the other machine.

Another useful, but unfortunately buggy program is called PNetKeys, which
is included in the ParBENCH package.  This utility does something very
cool.  When running, if you press `Left-Amiga P', the mouse pointer in
front of you will freeze, but if you look over at the other monitor, you
will be controlling the mouse and keyboard on the other machine!  The
mouse response is quite snappy, and typing across the net is real time.
To revert control back to machine #1, press the key combination again.
This could be extremely useful for CDTV or CD-32/SFX users that don't
have a detachable keyboard.  Unfortunately, I don't think this program
likes OS 3.0.  After using it a while it tends to lock up the network.
Again, if anyone knows of an update, please let myself or the editors
know, and we'll pass the information along.

For more advanced networking, S.A. Pechler, has written "Spar", a SANA-II
compatible device driver for ParNET.  It allows you to make ParNET
connections using several network protocols, such as AmiTCP, Envoy, or
AS225.  I have not tested this out, but it looks very useful, especially
if you are using a SLIP connection to connect one of your machines to
the Internet.  There is a similar package by Timo Rossi, called NetFS,
which looks equally promising.

LIMITATIONS -- What you can't do with ParNET
--------------------------------------------

First off, ParNET ties up your parallel ports.  That means you can't
run any parallel printer while running the network.  As far as I know,
if you have a multi-parallel port card, you cannot use it either while
ParNet is running, presumably because it ties up your parallel.device
access.  A parallel port switch box would be handy for when you need
to use the printer (and are not using the network at the same time).
The ParNET cable documentation mentions possible interference
with the serial port.  So far I have not had any problem with it, and
I've made many modem connections with the network running.

The second limitation is that ParNET only limits you to a two machine
network.  There was a lot of discussion on the nets about this last
year.  I know some people have tried to connect 3 or more machines
together, but I haven't heard of any successes.  It appears that ParNFS
may allow this to work however, as it describes it in the documentation.

In terms of performance speed, I have found ParNET to be relatively quick.
Certainly, it's not as fast as accessing a hard drive directly, but it's
quite a bit faster than floppy drives.  I'm getting transfer rates between
40-60 KB/sec.  That's about 3 seconds for a 150,000 byte file.  I'm
using an '030 optimized version of the parnet.device on both machines,
which was included in the ParBENCH distribution.

CONCLUSIONS -- Is it right for you?
-----------------------------------

Were it not for third party programs like AmiTCP, Envoy, and ParNET,
The words `Commodore' and `Networking' could rarely be used in the same
sentence.  If you are looking for a low cost, very functional network
to connect a couple of Amigas together, ParNET is a dandy solution.
It's uses are really limitless.  If you are into 3D, with a little
ingenuity, you can create your own mini render farm.  CDTV and
A590 CD-ROM drive owners can use these machines as inexpensive CD-ROM
servers for BBS setups.  I'd be interested in what some of you are
using your ParNETworks for.

If Jason is interested, I'd be happy to gather up the ParNET related
files I have for the AR Disk.  If you have any ParNET related materials
that are NOT on Aminet, feel free to send them to me in uuencoded form
to my e-mail address above and I will add them to the compilation.

[Yes, I'm interested...looks like a Coverdisk #4 release.  -Ed]

If you have a second Amiga that's gathering dust somewhere, get a
ParNET cable and try it -- you'll be pleasantly surprised.
Happy Networking!

COMPANIES MENTIONED
-------------------

Redmond Cable
17371 - A1 NE 67th Ct.
Redmond, WA 98052
(206) 882-2009

The Software Distillery
405 B3 Gooseneck Drive
Cary, NC 27513

Intangible Assets Manufacturing (Envoy)
828 Ormond Avenue
Drexel Hill, PA 19026
(610) 853-3733