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1990-05-13
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8KB
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189 lines
LAN-LINK Application Notes Number 1.
By Joe Kasser G3ZCZ
PO Box 3419
Silver Spring
Md 20918
Background
The main thrust of packet radio software development is in
writing code for the BBS and the Nodes, the user interface is
assumed and it stinks! Trying to control the TNC through the
keyboard is like trying to control a SSB transceiver through the
microphone. The software supplied by the TNC manufacturers
doesn't help very much. That software usually lets you adjust the
TNC parameters, most of which the operator doesn't understand
anyhow. LAN-LINK, written by Joe Kasser, G3ZCZ, is a different
program. It is designed to provide you with a window (your CRT)
into the LAN and to eliminate the need for you to know how to
control the TNC.
In the world of software marketing, once you have opened the
shrink wrap, the program is yours. Refunds are not normally
given. Too bad if the software is not what you needed. LAN-LINK
is different. LAN-LINK is marketed as Shareware. This means that
not only does LAN-LINK have a 100% return of fee policy- no
questions asked, if you are unsatisfied for any reason (within 30
days of registration), you must be happy with it before you pay
for it. This is because you get a chance to evaluate Shareware
software BEFORE paying for it. If you don't like it, you don't
have to use it, and don't have to pay for it. With this
marketing approach, Shareware HAS TO BE GOOD.
Joe Kasser's, thoughts and comments on computers in Amateur Radio
have been published in two books and numerous magazine articles.
He is also the editor of the AMSAT Journal. He has a 20 year
background in aerospace, amateur radio and the man-machine
interface. He spent the last three years writing LAN-LINK to
both simplify the user's interface to packet radio, as well as to
provide the user with a smart terminal. LAN-LINK is not a TNC
controller program or a mail box. LAN-LINK provides each user
with a window into the LAN. LAN-LINK is menu driven so that each
user can dive as deep as necessary into the program's features.
This series of application notes, shows you, the operator, how
you can smarten up your use of packet radio and other digital
communications by using smart software in your PC.
Introduction
With the Space Shuttle Columbia (STS-35) about to blast off
carrying the Shuttle Amateur Radio Experiment (SAREX) mission,
this is a good time to start off a set of application notes on
using LAN-LINK. Like any other computer software manual, the
LAN-LINK manual tells you what the controls (menus and function
keys) do, it does not tell you how to use LAN-LINK. These
application notes are intended to do just that.
STS-35 is the most exciting event in packet radio this year.
Unfortunately due to the primary astronomical payload misson
constraints, the Space Shuttle will pass over the US, in the
main, during darkness. At weekends staying up for a connect
attempt may be fine, however during the week, that may be a
problem. LAN-LINK 1.55 (and up) has features built in to it to
allow you to make a connect with the orbiting SAREX Robot, while
you are at the office, or even fast asleep.
Working SAREX
First thing to do, is to set your 2 meter transceiver to receive
on 145.55 MHz and transmit 600 kHz lower on 144.95 MHz. Set your
deviation low so that your signal is not Doppler shifted out of
the SAREX receiver's passband. You can do this simply enough by
asking someone to listen to your signal's audio, while you
gradually reduce your transmitter audio gain.
The next thing you ought to do is to configure LAN-LINK to
capture to disk any packets addressed to or from the SAREX
callsign. You do this by bringing up the AMSAT-OSCAR Menu and
chosing the SAREX sub-menu. A [S] will be displayed in the status
window when this option is active. The capture-to-disk file is
opened by a packet header containing the SAREX call, and closed
by another packet header not containing the call. When the file
is open, the [S] will blink. Packet headers are considered to be
lines with a '>' character in them. LAN-LINK thus considers both
of the lines below as packet headers.
N4QQ*>G3ZCZ
N4QQ BBS>
If you use this feature for monitoring BBS traffic, the BBS
prompt lines ('E.G. N4QQ BBS>') will not be captured to disk. Do
not get your SYSOP to remove the '>' from the prompt line, or the
ZAP feature will then not work.
A happy face will be displayed next to the 'S' in the [S] after
the SAREX call has been heard.
Lastly, using the 'Terminal Menu', set the Terminal mode to
'Everything' to allow you to view all packets on 145.55 MHz.
Manual Connect Requests.
If you happen to be awake when the Shuttle comes into range, then
try to connect to it manually. LAN-LINK has two ways of doing
this.
Try using the Alt-C function key. When you activate the Alt-C
key, LAN-LINK will prompt you for the call. Enter WA4SIR-1, and
LAN-LINK will try to make the connection. If for some reason it
fails, push the Alt-R key and it will retry.
If you have copied at least one packet from SAREX, then push the
F5 key and move the cursor down and over to the SAREX callsign or
WA4SIR-1. Place it on any character in the call and push the
"Enter" key. LAN-LINK will then try to make the connection. If for
some reason it fails, push the Alt-R key and it will retry.
Automatic Connect Requests
Bring up the AMSAT-OSCAR Menu and choose the SAREX option. First
make sure that the SAREX Call is set to WA4SIR-1. Then turn the
Attack Mode ON. When the Attack Mode is set, this option will
cause LAN-LINK to issue a connect request to the SAREX Call
whenever a packet sent to or from it is heard. The mode is
cleared when the connect is made (and does not retry out) or when
the 'A' option is selected a second time, or when the Alert Call
is cleared. If this mode is enabled, the Alert/SAREX Call prefix
shown in the Status Window will indicate accordingly.
A happy face will be displayed next to the '>' before the call in
the Status window once the connect has been achieved.
The Periodic Event Way.
If you have a set of Keplerian elements, and know when the SAREX
will be in your range, you can set LAN-LINK to start issuing a
blind connect request to WA4SIR-1 just before the Acquisition of
Signal time, at periodic intervals through the pass, and to stop
just after Loss of Signal time.
Bring up the Event menu, and select the Periodic Event option.
Enter the the start time, the finish time and the time interval
between the connect/call attempts. The first connect that goes
through will clear the event scheduler.
If you really want to make a connect withe the SAREX, one of
these LAN-LINK features ought to let you.
I strongly suggest that you test the automatic features before
you sleep on it, just to be sure. From the SAREX menu, change the
SAREX call from WA4SIR-1 to that of your local Net Rom, The Link
or KA Node. DO NOT set it to a BBS call.
The next time you see a packet from the Node, your station should
try to connect to it and capture-to-disk to packets with the
node's call in the header.
Don't forget to change it back to WA4SIR-1.
Afterthoughts
1. If you want to see an early version of what Ron will see as an
ORBITER menu when he wants to control the SAREX Robot,
temporarily change the SAREX call to be the same as your call
and bring up the AMSAT-OSCAR Menu.
2. Send an edited summary of the contents of the real SAREX
capture-to-disk file to SAREX @ W3IWI via packet, for a QSL
card for a reception report. Just send copies of one or two
packets containing all the calls.
3. You can also use this feature to try to connect to a DX-
pedition running packet radio (such as the 4J6X DX-pedition in
late May) while you are at work. How about that! Now your
station can work those future rare DX stations, and you won't
need to be 'sick' at all.
73 Joe G3ZCZ
LAN-LINK is available from the author. For an evaluation copy,
download it from Compuserve or send $5.00, or send $35.00 for a
registered copy which will entitle you to at least one free
update. When you write in, say where you saw this Application
Note.