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EnigmA AMIGA RUN 02 (1995)(G.R. Edizioni)(IT)[!][issue 1995-11][Skylink CD].iso
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1995-09-30
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FLOPPY DISK PORT BASED AMIGA NETWORK
Sent By Floozie
By Douglas J. Nakakihara
Spectronics International U.S.A. is now shipping a terrific product
called AmigaLink that allows Amigas to be networked using the floppy
drive port! Now even slotless models like the A500, A1200, and CDTV can
be part of a network.
Although networking usually involves multiple users, single users can
also benefit. Each step in the evolution of the Amiga has meant some
incompatibility or another. As a result, many Amiga owners continue to
hang on to them, even after purchasing a newer model. By networking
them, peripherals can be shared, allowing maximum use of all hardware.
PARNET
Of course, many Amiga owners already rely on the freely-distributable
ParNet software to network Amigas. Like ParNet, AmigaLink is also a so-
called peer-to-peer network because all of the nodes (i.e., networked
computers) are equals, and any one of them can access another's storage
devices. A4000-Toaster owners will appreciate the fact that AmigaLink
also doesn't use an expansion slot.
However, as wonderful as ParNet is, it's just a toy compared to
AmigaLink. A downside of using ParNet is that only two Amigas can be
networked, AmigaLink can have up to 20. Furthermore, because ParNet
monopolizes the parallel port, it can be a real pain using other
peripherals that use this port, like a printer, scanner, or audio
digitizer. ParNet also provides no access-security between nodes.
Although, 20 is the recommended maximum number of nodes, that number
can be exceeded, as can the recommended cable length limit of 330 feet.
Apparently, the amount of interference at the network's location
determines the actual maximums. But this can only be determined by trial
and error. For example, using shorter cabling between nodes, may allow
you to exceed 20 Amigas.
INSTALLATION
Although the manual provides adequate step-by-step instructions, they
are spread over several chapters and the process takes longer than it
should. Because installation is fairly involved, it would have been much
better if the installation steps were consolidated and preceded by a
brief overview of the procedures. In spite of this, I had two nodes up
and running in about one-half hour.
HARDWARE HOOKUP
To install AmigaLink, you must first physically connect the computers.
The petite AmigaLink adapter is basically a 23-pin connector with a BNC
T- connector protruding from where a cable would normally exists. A
removable terminating cap is attached to one end of the T-connector.
AmigaLink will work with pass-through connectors and you can still have
up to three floppy drives on each Amiga.
Each Amiga must have its own adapter and 50-ohm RG-58 coaxial cabling
is supplied to connect the them together. By removing the terminating
cap, you can daisy-chain multiple computers together; however, there must
be a terminating cap on the first and last nodes. The procedure is easy
and you don't even have to open a computer case!
The T-connector portion of the adapter is removable and you can
disconnect or reconnect nodes without powering down. Connections will be
re-established once nodes are reattached. However, you should never add
or remove an AmigaLink adapter while the computer is running.
SOFTWARE INSTALLATION
The software is installed in three steps. First you must install the
device driver on each Amiga. This is accomplished by merely clicking an
icon and following the instructions. The manual provides detailed
instructions on what AmigaDOS commands must be available for the
installation script to work properly (e.g., Run, NewCLI, Copy, etc.). If
the software is being installed on a floppy disk, you must delete some
files to make room for the AmigaLink software. A handy list of deletable
files is provided for Workbench 1.3 and 3.0 disks. Between the two, you
can come up with a list for a 2.x Workbench disk. Obviously, you should
use a copy of your original Workbench disk.
The second step is to install the file system software on each
computer. Again, this is a click-and-go procedure. During this process
you will be asked for a "host" name. Each node must have a unique name,
like "Dougs4K", or "CDTV1." I'd recommend that you keep names as short as
possible for reasons you'll see later on (I was surprised to find that
the AmigaLink device driver is SANA-II compatible (Standard Amiga Network
Architecture). This means that ENVOY or other SANA-II compatible
networking software can be used instead of the AmigaLink file system
software.)
CONFIGURING NODES
Once the device driver and file system are installed on all Amigas,
the third step is to run the configuration programs on each node. These
programs do not have to be installed on each node and can be run from the
AmigaLink floppy disk. However, I found it more convenient to copy them
to my hard drives for possible future configuration changes. There are
two configuration programs: Import and Export.
EXPORT
Export allows you to identify which devices are available to other
nodes. Remember, AmigaLink is a true multi- user network. As such, you
can keep certain devices private and not allow remote access. This
covers all storage devices including RAM: and removable media, like
floppy drives (a disk must be present).
The Export settings can be saved as a default or just used for the
current session. The settings file is saved in the ENVARC: directory
under Networks. (ENVARC: is a standardized storage area for
configuration information.) You can also save multiple settings.
IMPORT
Running the Import program brings up a list of the other nodes on the
network, called "hosts." By selecting one of the hosts with the mouse, a
list of all of its available (i.e., exported) devices appears. You can
then select which devices should be mounted on this particular node.
(Normally, the Export program should be run on all nodes before running
the Import program.)
To avoid name conflicts, Import automatically appends the name of the
Host to the front of the device and volume names (Remember, every Amiga
storage device has both a device and volume name, which are usually
different.) For example, the device and volume names "HD1" and "Work" on
host "A3000" become "A3000-HD1" and "A3000-Work", respectively. So if a
node already had a HD1 device called Work, a similarly named device on a
remote node could be accessed without conflict. The default names can be
changed, however.
The Import settings are saved in a file in the WBStartup drawer.
Although this is a logical location, booting up without all nodes active
will yield a slew of annoying error requesters. You can drag the Import
icon out of the WBStartup drawer, but you'll have to move it every time
new settings are saved. I remedied this by adding some lines to my
Startup-Sequence that checks for the Import files in the WBStartup drawer
and then moves them to another drawer. This works because the Startup-
Sequence is executed before WBStartup programs are run. I don't know why
the Import settings aren't saved in the ENVARC: directory just like the
Export settings. This would allow the Import startup icon to be placed
anywhere.
UTILITIES
Diagnostic utility programs are also supplied. One is a self-testing
program which identifies hardware problems. Two other programs test the
receiving and sending abilities of computers on the network. The
Statistics program monitors and displays network performance information.
NETWORK PRINTING
AmigaLink comes with a utility program called Spooler, which allows
multiple nodes to "print" to the same printer. Spooler is run on the
node with the printer, referred to as a "print- server." The program
monitors a user- specified directory for activity. When a file is
completely "printed" to that directory, Spooler sends it to the printer
port, usually PAR:, and then deletes the file.
All other nodes must run the AmigaDOS CMD command, usually found in
the Tools or Utilities drawer. Generally, CMD is used to redirect
printer output to a file in RAM:. However, the output it intercepts can
also be redirected over the network to the monitored Spooler directory.
You should be able to set up multiple print-servers, each running its own
Spooler. Nodes could then print to any of these servers by simply
changing the CMD redirection.
Do not run CMD on the print-server, however. Doing so will create an
endless loop: CMD redirects data headed for the parallel port to the
Spooler directory, Spooler then sends this back out to the parallel port
- you get the idea.
OS1.3
Although, AmigaLink was developed for OS2.0+ users, it functions fine
using OS1.3 (reportedly even on an Amiga 1000). It's not as automated as
under OS2.0+, so you'll have to use some CLI commands. However, you can
modify your Startup-Sequence to automate the process. Remember to
include the StartServer command, as the installation process does not do
it for you.
MY NETWORK
My test network consisted of an Amiga 3000, 4000, and CDTV. The CDTV
required using a pass-through external floppy drive. Since many external
floppy drives, like the "official" black CDTV ones, do not have a pass-
through connector, Spectronics will be releasing an inexpensive
T-connector providing pass-through capabilities. An adapter for CD32 is
supposedly in the works too (Note: If you don't have a keyboard for your
CDTV, there are a few public domain utility programs that emulate
keyboard input using a mouse.).
I was extremely impressed with the AmigaLink. The network is
professional and well implemented. Remote devices function just like
local ones and their icons appear right on the Workbench, including "left
out" icons (OS2.0+)! The network is virtually invisible. Here is where
my earlier suggestion for short Host names comes into play. Volume names
that display wider than their icon, will make for a real ugly Workbench!
This is not a functional problem, but could become aesthetically
annoying.
To network a CDTV, you'll need to have a non-booting CD inserted into
the unit so it will boot off the floppy drive. I was happy to find that
AmigaLink handled changing the CD's. Although the volume name didn't
change, I could still access it. To get the name to change you must
unmount and remount the device.
When I rebooted a node, I found that on remote nodes, I had to unmount
and then remount any devices imported from the rebooted node. This was
so, even though the Import program indicated the devices were mounted.
You can click the "mounted" button twice or do it from the CLI. When
there are a lot of devices, a script file to unmount devices works great.
I also found a conflict between by Goldengate 486 board and AmigaLink.
However, as long as I didn't try to access a device on the Amiga with the
GG486 while it was emulating, all was fine.
PERFORMANCE
Since Amiga floppy drives are no speed-burners, I was very interested
to see what kind of performance a floppy port network could achieve. The
manual states that the data transfer rate is 450,000 bits-per- second,
which translates to about 55 kilobytes-per-second (kbps). My best case
was a disappointing 40kbps on my network, while ParNet achieved around
61kbps.
However, this is only half of the story. During transfers, ParNet
hogged CPU time, while AmigaLink barely required any. So although
AmigaLink is slower than ParNet, it uses substantially less system
resources, which could be a factor when multitasking. Still, AmigaLink
is just fast enough not to cause an anxiety attack.
VIDEOTOASTER FARM
Spectronics is also considering releasing software to do simultaneous
Lightwave rendering on multiple Amiga/Toaster systems. This is an
excellent application for AmigaLink because a fast transfer rate is not a
requirement. "Rendering farms" - just like the big boys (i.e., Amblin
Imaging (seaQuest DSV) and Foundation Imaging (Babylon 5)) - are now
within the reach of smaller 3D studios.
WORTH THE PRICE
This is an extremely important product for the Amiga and one that I am
very excited about. At $260 for a two-node network, AmigaLink may seem a
little expensive, but a functionally equivalent Ethernet-based network
would cost you many times that. AmigaLink performs like a full-fledged
network - albeit a little slower - and is well worth its cost.
AmigaLink, $259.95 for two computers $124.95 for each additional
Spectronics International U.S.A., Inc. 34 East Main St. #3, Champaign,
IL 61820. Tel: (217)352-0061 .
END
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