Amiga Tools 3/Amiga Tools 3.iso/demo/fun/mags/mb-oct95/docs/mb_46.txt

Text File | 1995-09-30 | 13.3 KB | 251 lines

                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:  [phone] .

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