HELP.TXT 6.0               APRS HELP DOCUMENT


    In most cases, all APRS commands are active from all pages and APRS
processing of packets continues in the background.  (An exception is while a
BLUE-BOXED prompt is on the screen).  The first Help page defines all command
characters.  All APRS commands are single key strokes.  Some keys bring up
additional command sub-menu's on the bottom of the screen.  Just hit the
first letter of any command listed in the prompt.  In most prompts, the
ENTER key will select the default choice or complete the prompt with no
action.  To begin with, APRS has nine major display screens:

  MAP       - For showing the positions of all stations and objects
  LATEST    - Shows the latest Beacon or broadcast message for all stations
  BULLETINS - Shows all general announcements posted by other stations
  POSITIONS - Shows position packets and comments from all stations and Objs
  HEARD LOG - Shows station activity in number of packets per hour per station
  READ MAIL - Shows the last 23 message lines heard between any stations
  DIGIs USED- Shows digipeater paths used by all stations (or DX message list)
  ALL BCNS  - Chronological log of all beacons and messages (or all DX spots)
  VIEW      - Scrolling screen of all packets on frequency


DISPLAY SCREENS:  Each display page is called up with a single key command as
shown below.  If there are more than one page of packet stations in the net,
then use the PgUp and PgDn keys to cycle through multiple pages.  On both the
P and L lists, you can move the cursor to select a single station.  A prompt
then allows you to (1) display the object on the screen, (2) see a chronologi-
cal list of all previous beacons from that station, (3) delete the entry,
(4) insert a position for a BEACON only station, etc.

  L - LATEST DISPLAY - Lists the latest BEACON packet from all stations.  This
      screen is like a braodcast message display showing the latest bulletin
      from each station.  In DX mode, this screen lists all stations on your
      local cluster and their latest outgoing packet.

  B - BULLETINS DISPLAY _ Shows the latest 22 APRS BULLETINS.  This screen is
      very useful for distributing useful net-wide information about special
      events or instructions.  Any station can post multiple lines to all
      stations using these BULLETINS.  See the SEND command

  P - POSITIONS DISPLAY - Lists the latest POSITION packet received from each
      station.  Since each position report can contain comments, this display
      is useful for seeing comments and resolving position data.  You may
      select (HOOK) any station or object in this list for manipulation.  See
      the section on OBJects.  Also the JUST ONE command works on this display
      to show JUST one type of stations at a time.  On the PList, you can HOOK
      any object or station with the cursor and then you may execute a number
      of different commands on that object:

          U or Q - Uplink or Quit uplinking that object
          Move   - Move it anywhere else on the map
          Show   - Center the map on the object
          Delete - Deletes the object from your list
          Just   - Lists only stations or objects of JUST one type
          Kill   - Stops display of your object on EVERYONE's screens!  It
                   remains in their list but just does not clutter the map.

  H - HEARD - This display shows statistics of the number of packets heard
      from each station for the last 24 hours.  It is useful for observing
      station activity and on HF for observing propagation changes.

  R - READ MAIL - This screen monitors all messages on the frequency and keeps
      the last 23 lines heard.  This screen is useful for "READING the MAIL"
      In DX mode, also collects TALK messages between DX cluster users.

  D - DIGIPEATER PATH - This display shows the raw packet header including
      the digipeater paths used by all stations in your LATEST list.  Proper
      use of digipeaters is very important for minimizing QRM on APRS nets.
      In DX mode, this screen accumulates the list of all ACTIVE MESSAGES.

  A - ALL PACKETS - This display shows a chronological history of all packets
      received.  It also includes your incoming and outgoing message lines.
      Since messages do not have a time of receipt appended to them, this
      display is useful for seeing approximately when a message line was
      received.  In DX mode, this screen accumulates all DX/WX/WWV spots and
      all announcements.

  F1- HELP - Gives a menu of several different pages of HELP.  New in version 
      6.0, you can now read all of the README files on-line using the F1(HELP)-
      FILES command.  Other screens in the help menu are as follows:

      AEA     - Hints on how to initialize the non standard AEA products
      DIGI    - one screen on how to use APRS DIGIPEATERS
      FILES   - New in 6.0, lets you read README files on line
      HELP    - Full page listing of all APRS Commands
      INFO    - A screen of additional helpful information
      MORE    - A second page of help
      NEW     - New-user simplified help screen
      On-SCRN - Scroll through the commands without losing the current screen
      SYMBOLS - Shows all the APRS symbols available
      VALID   - How to validate your copy of APRS



MAP DISPLAY:  The map display is the most important display in APRS.  It shows
a map of the packet network area and the positions of all reporting stations.
Stations reporting packet positions over the air are shown in white, objects
that you are reporting to the network (uplinking) are shown in yellow, objects
reported by other stations are shown in purple, positions that have not been
updated in 2 hours are shown in dark gray.  Stations shown in light gray are
beaconing a position, but do not have APRS on line.  To help highlight the
WIDE area digipeaters in an APRS net, the WIDE digipeaters are shown in green.
All weather stations are shown in blue. and finally, all moving objects that
have been deadreckoned, are shown in light blue.

  SPACE   - Displays the current map.  By marking important or special objects
            with a # on the P-list, you can display the map with all other
            stations or objects suppressed by simply hitting the # key.  If
            you press *, all symbols will be displayed, but only the calls
            of the marked stations will be shown (useful for tracking a mobile
            through a maze of fixed stations..)

  ARROWS  - Move the map cursor on the screen.  If you turn NumLok off then
            hold the shift key with the white arrow keys, then cursor will
            move 5 times faster.

  PgUp/Dn - Zooms the display in and out by a factor of 2.  Ctrl-PgUp/Dn
            zooms by a factor of 8.

  Home    - Will home the center of the screen to the current cursor location

  ESC     - Will escape the cursor from never-never land to the screen center

  End     - Will return the map to your default position stored in CONFIG file

  1,3,5,9 - These are map memories that you can use to save particular maps
            of interest to you.  Save a map using the MAP-SAVE command and
            recall any of these using the indicated number key.  The 1 key
            always has the whole USA in it.

  F9      - CENTER ALL CONTACTS.  This special function will calculate the
            best map range and center ALL stations heard by you on one map.

  J       - JUST ONE - Used to display just one symbol type at a time.
            to selectively display stations like all WX stations.

  #       - Will display the map with ONLY the objects or stations marked on
            the P-list with a #.  Very useful for highlighting special event
            objects with a single key stroke.

  *       - Similar to # above, but displays all objects, but only the calls
            of the marked stations.

  HOOK    - Hook is a Navy term for selecting an object on a radar screen. Use
            the RETURN/ENTER key to hook an object at the cursor location.  To
            progressively hook one object after another, use the  +/- keys.
            The POSITION and BEACON packets from a hooked station are displayed
            on the bottom of the screen.  While a station is hooked, it can be
            moved by moving the cursor to the new location and hitting the
            INSert key or it can be removed using the DELETE key.  To prevent
            inadvertent movement of objects, a second RETURN key UNHOOKS.

  INSERT  - Relocates a HOOKED object on the screen.

  DEAD RECKONING:  Since APRS dead-reckons the position of moving objects as
            time progresses, the light blue symbols on the map are presented
            where they are predicted to be, NOT where they were at their last
            report (unless DR is off).  If you use the cursor to try to hook
            one of these objects on the map, you must hook the little gray
            circle which marks the position of the actual report, and not the
            symbol itself.


MAP MENU:  Many of the MAP features and other commands affecting maps have
been moved to the MAP MENU.  The following commands apply:

  A - ALTmap:  Displays the map UNDER the current map.  Since APRS always uses
      the latest map in the MAPLIST.APR file that meets the current
      screen conditions, areas where maps overlap may sometime be
      obscured.  This command displays the next higher map in the list.

  B - Borders:  Shows borders of all MAPS in the MAPLIST.apr file.  If A map
      border appears, but does not come up, then the MAP file is
      missing.  If the Map file exists but the borders do not show
      up, then the file is not listed in the MAPLIST.apr file.  Use F3 and F4
      to display more or fewer borders.  See Hierarchy command below.

  F - Features Toggles a number of map features on/off.  Features are Boundaries,
      Headings, Roads, Calls, Waterways, etc.  ALL features can also be
      turned on/off at once.  This is useful for slow 8088 PCs where
      turning off the map still shows the relative positions of stations
      but without taking the 10 seconds required to draw the maps.

  G - Grids:  Select any of the following:
      CAP - Overlays the Civil Air Patrol search and rescue grid system.
      GridSquare - Displays Maidenhead grid squares

  H - Hierarchy:  This is an improvement on the BORDERS command since it
      colors in the maps in the same sequence as they are listed in the
      MAPLIST.xxx file.  The overlapping colors show the effect of the
      sequence of this list.

  L - Locks the current map.  This defeats the normal APRS auto-map select
      feature so that you will not be interrupted if your cursor gets over
      on another map during a special event.

  R - Rings.  Select from a number of Range rings:

      DFrings:  Displays Signal strength contours around all stations
      reporting signal strength on a fox/jammer.  Stronger signals are
      brighter red and null reports are black circles.

      POWER rings:  Displays range rings around all stations on the map
      showing an estimate of the horizon from each station based on their
      transmitter power, height above average terrain, antenna gain and
      favored direction.  If specific parameters are not given for a station,
      then the defaults used are 10 watts, 20 feet, and 3dB gain, omni.

      RANGE RINGS - Displays one ring at the current range scale and another
      at half the range.  This display also shows the range and bearing of
      the cursor from the center of the map.  This is limited to 256 miles
      since it does not calculate great circle spherical results.



MESSAGE TRAFFIC:  There are three types of messages in APRS.  The first is
simply your one-line BEACON that is always transmitted to all stations.   New
BEACONS are shown at the bottom of all USER's screens on the net and  are
highlighted in green so that all stations see the new message or change in
status immediately.  These BEACONS are also added to the ALL and LATEST
pages of all stations on frequency.  These beacons are perfect for alerting
the net to your current status.  Secondly, APRS implements a one line TALK
traffic capability between operators.  Each line is ACKed when received by the
other station.  Multiple lines can be buffered up for eventual delivery.
Finally, after APRS version 506, any station can sent a multi-line BULLETIN
to all stations.  See BULLETINS page and the SEND command.

TRAFFIC COMMANDS:

  B - Displays any Bulletins.

  T - Displays traffic on the current screen.  If messages are already on the
      current screen, then T forces a one-time transmission of all messages,
      without changing the current timing.   Whenever you call up a new
      APRS screen, the messages are overwritten.  They will reappear if there
      is any change, such as an incoming message line or an ACK to one of
      your outgoing lines.

  S - SEND MESSAGE - You are then prompted for the callsign of the station
      that you want the message to go to.  If you already have outgoing
      message lines pending, then the previous station callsign is pre-loaded.
      If you don't want to send the message, just enter a blank line.  If
      you have hooked a station on the map, then that stations CALL will be
      pre-loaded.

      NOTE: The channel effeciency of APRS TALK messages are no better than
      normal connected packets since they also require ACK's.  Intense
      real-time rag-chews on a busy APRS frequency should be done without
      digipeaters or with only the exact path specified;  See the OPS-DIGI
      command below, for a shortcut for rapidly changing your digi path.
      The more effecient way to keyboard is to just use the OPS-COMM command
      and use your TNC to connect to the other station using the most direct
      path.  The other operator MUST be at his keyboard, though, because APRS
      will time-out, erase his screen, and dump him back into APRS after 3
      minuntes of inactivity.
 
      ACKS:  When your MSG is acknowledged, the word *ACK* (or *REJ* if his
      screen is full) will be over printed on the outgoing MSG line.  Note that
      unlike normal packet, APRS does not compute the return path for an ACK.
      Each station must set his outgoing VIA path so that his packets
      (including ACKs) get back to all stations in the net.  On the 3rd DUPE
      of an incoming message, APRS will warn you that the other station is
      probably not getting your ACKS!  In version 505, APRS waits 30 seconds
      and repeats the latest ACK once to provide an almost doubling of
      through-put on poor (HF and multi-hop digipeater) paths.

  S - SEND BULLETIN.  This is the same as the SEND command, but you simply
      send the message to BLN# instead of a callsign.  The # indicates which
      line of the bulletin it is (1 to 9).  All stations that see a message
      addressed to BLN# will grab it and sort it onto their BULLETINS page.
      Notice, since no one ACKS these message lines, they are transmitted
      forever at the normal APRS decaying perodicity, eventually being sent
      about once every 15 minutes.  This way, new stations checking into the
      net will eventually collect all old beacons still being transmitted.
      You can update or change lines, just be sending a new one with
      the same BLN number.


  K - KILL incoming message lines.  K key kills one line at a time.

  E - ERASE outgoing lines.  E key erases one outgoing line at a time.  First
      it erases *ACKed* messages, and then erases other lines.


FILES MENU:  All commands dealing with files have been placed in the FILES
Menu.  These commands are as follows:

  A - APPEND - This will permit you to load in a BACKUP file without losing
      all the stations that are already in your P and L lists.  If the same
      calls are in the appended file as are already in memory, there will
      be numerous dupes that should be manually deleted.  Also, APPEND does
      not append any LOG or WHEN-HEARD data.

  C - CHANGE-MAPLIST - This command finally lets you build and use multiple
      MAPLIST.xxx files customized to your area and application.
  
  D - DOS Shell - allows you to shell to DOS.  Be sure to return to the APRS
      directory before you EXIT back into APRS.

  L - LOAD - This key allows you to load a backup file.  The file named BACKUP
      is saved every time you quit APRS so that you can restart the program
      to the last on air situation.  I save a different file for each packet
      frequency so that my map only shows stations on the current frequency.
      To facilitate this process, you only need to enter the numeric digits
      to LOAD a backup FREQxxxx or HFxxxx file.  To load the BACKUP file, just
      enter the letter B for the filename.

  O - ORDER THE LATEST LIST - Moves older beacons to the start of the list,
      and the most recent beacons to the end.

  S - SAVE - Used to save the current situation in a file.  The file name
      defaults to the name of the last file loaded.  It is a good idea to
      save a separate file for each packet frequency on which you operate.
      If any filename other than the BACKUP default is entered, then APRS
      will also automatically save a LOG and Track HIStory file.  If you
      select NONE as a file name, then nothing will be saved.


OPERATIONS MENU:

  C - COMMS - This commmand allows you to disable APRS and talk straight
      through to your TNC or GPS/WX/DF COMM port.  Use it to establish a
      direct CONNECTION.  This is useful for connecting to another APRS
      station's internal TNC mailbox to leave a message if he is not on line
      with APRS or for a quick keyboard to keyboard QSO with another APRS
      operator, known to be at his keyboard.  These brief keyboard connections
      are not too disruptive to other APRS operations on frequency as long as
      no computer data is transferred.  Also permits you to monitor your other
      COM port hooked up to GPS or WX.

  D - DIGIPEATER PATHS:  This is a very useful command that allows you to
      save and later use a variety of digipeater paths.  You can save up to
      13 different paths.  Simply hit S to save your current path into one
      of the memory slots.  The L key will display a list of already saved
      paths.  When you are in QSO with one station in particular, choose the
      minimum path to that station to minimize QRM on the channel.
 
  F - FIND:  This command allows you to find a callsign or a gridsquare.  If
      you enter the first character as a [, then APRS will asume the entry is
      for a grid square.  If you just type a callsign, then APRS will search
      for the given callsign.  If you are on the MAP, then the station will
      be identified.  If you are on any other screen, APRS will jump to the
      page that holds that callsign.

  Q - QUERY:  This command sends out an APRS query packet (in about 5 secs) to
      all stations on frequency.  All APRS stations will respond with all of
      their BEACONS, POSITS, OBJECTS, and MESSAGES sometime in the next 2
      minutes.  This command is AUTOMATICALLY sent when a station starts
      up the  APRS program.  This is why you hear a lot of packet
      activity each time a new APRS station fires up on frequency.  You
      can selectively Query any single APRS station by sending him a one-
      line message with the characters ?APRS in it.

  P - PING -  Sends out a ping packet.  If the packet is digipeated by your
      selected VIA path, you will see it monitored on the bottom line of
      your display.  This lets you know that your station is transmitting
      and that the digipeater in your selected VIA path responded.

  U - UNPROTO  Used to set up your outgoing digipeater path. (IMPORTANT!)
      If you have not selected a digipeater that covers your APRS net, then
      your packets and acks will never get to the other stations on freq
      even though you see them fine.  YOU MUST SET YOUR VIA PATH TO COVER
      your intended APRS AREA by selecting an appropriate digipeater path!
      APRS will warn you if another station does not appear to be getting
      your message ACKs.


INPUTS MENU:  Lets you ADD objects to the map, or input data on your station.
Any station may ADD an object on the map for display at all stations.  Once
on the screen, the object is listed in the P-list with a (+) symbol.  This
means it will be transmitted by your station.  You can QUIT transmitting each
object by hooking it on the P-list and hitting Q.  Users with an un-validated
copy of APRS are limited to uplinking only one object.  Even if you delete the
object from your screen, or have quit sending it, it still remains on all
screens in the network until each individual operator deletes it.  To remove
it from all screens, you can kill an OBJECT instead of deleting it.  Your
station will continue to transmit the object, but with a special KILL mark
on it.  It will disappear from all maps, but it will REMAIN in everyone's
PList.  If an object has not been updated in over two hours, it fades to a
dark gray color.

In some of these commands, you are prompted for the LAT/LONG of the object.
APRS pre-loads this prompt with the LAT/LONG of the cursor.  If that position
is correct, just hit ENTER, and these values will be used.  TO change these
values, just type in a new value.  You may type as few characters as needed
to give the resolution you need.  But you MUST always type the required
LEADING ZEROS in longitudes below 100 degrees.

  A - ADD a new object to the screen at the current cursor location.  You
      are prompted for all pertinent information.  There are over 50 symbols
      that can be used to display the object.  Some are specific and some
      are generic so that they can be defined for each special APRS net.

  D - DIRECTION FINDING:  This command allows you to enter a beam heading or
      a signal strength report for your own station during direction finding
      events.  A zero (0) bearing indicates a signal strength report.

  M - MyPOSIT:  This command added in 5.7 permits one step updating of your
      position without having to first hook yourself.  This makes updating
      your position while APRS mobile with a good map, so easy, that you only
      need GPS if you are lost!

  P - POWER:  This is the command used to enter your transmitter power, height
      above average terain, antenna gain, and directivity.  This makes sure
      that your station range will be properly estimated.

CONTROLS:  There is a status display called the control panel which can be
displayed at the bottom of the screen.  It shows the status of all toggle
on/off functions, your validation status and your VIA path.  Items in lower
case are OFF and upper case are ON.  Example:

------------------------------------------------------------------------------
 XMT | UP | DR | LOG | PFL | BCNS | cw | VHF | DIGI-1,DIGI-2     |
------------------------------------------------------------------------------

  B - BEACONS - Used to return APRS to monitoring BEACONS only.

  D - DX mode - Sets up APRS to monitor and display information for DX cluster
      users.  See DX.txt.  To exit this mode, select either BCNS or OTHER.

  F - FADE - This toggles on/off the automatic fade-to-gray for old contacts.
      Old objects and stations on the screen normally turn to gray after 2
      hours.  This made backup files of past events look boring with all
      contacts barely visible!  FADE is now turned OFF each time you load a
      backup file, but after 2 hours, FADE will automatically come back on.

  G - LOG - Toggles on and off the automatic logging of track histories to
      file.  Default is ON so that after 150 position reports, a file is
      automatically saved and memory is cleard for further accumulation.  If
      off, the 150 reports are retained in memory until you QUIT.

  O - OTHER Use this command to toggle the APRS beacon processing
      filter between APRS Only packets or ALL OTHER packets.  The state
      of this switch in shown on the control line.  Use OTHER to monitor
      non APRS frequencies to collect BEACONS and see who is on the air.
      With OTHER selected, no packets are saved in the ALL list.

  P - POS-FILTER ON/OFF -   If a position is the same (within 20 yards or
      .01 minute of LAT/LON), then the report is not saved in memory or to a
      track history file.  If this POSITION filter is on, then the comparison
      is made out to 80 yards to include most of the randomness added to the
      GPS system by the Deaprtment of Defense.  This prevents non-moving GPS
      packet stations from filling up track history files with redundant
      positions.
 
      When the 80 yard filter is disabled, this ENABLES the automatic saves
      of all WX and DF reports to the HST files which is useful for later
      trend analysis.

  R - dead Reckoning On/off

  U - UPLINK ENABLE - Toggles on/off.  If on, then your objects marked
      for uplinking, will be uplinked to all stations in the net.

  X - XMT ON/OFF - disables routine transmitting from your station.  This is
      good for stations monitoring an event, but not actively participating.
      It keeps their routine beacons off the frequency.  The X key will force
      a one time transmission of your BCN, POS, OBJ, and MSG packets and your
      station will still ACK incoming messages.

  W - CW - In normal mode, if CW is on, then ALL NEW BEACONS will be sent to
      you in CW.  In DX mode, CW is always on, although it can be silenced by
      using the SETUP menu to turn BEEPS off.  If FREQS is turned on, then
      the operating frequency as well as the callsign will be sounded out in
      DX mode.  Other CW functions:
 
      E - Enable    D - Disable    F - FREQs on   S - Set speed    T - Test
 
      Lines to you are sounded out in CW if you are not near your CRT.  Also
      permits changing speed and selecting Full calls in DX mode.


SETUP MENU:  This command allows the selection of all SETUP functions.  These
functions can be saved in a configuration file by registered users

  B - BEEPS Toggles nuisance BEEPS (and CW in DX mode) on and off.

  G - GPS FUNCTIONS:  Select, or initialize a number of GPS functions:
      SPM       - Single Port Mode (See GPS.txt)
      HSP       - Hardware single port mode (see GPS.txt)
      KLYNAS    - Sets up APRS to work with STREETS-ON-DISK (Klynas Engineering)
      NoGPS     - Used to turn off SPM or HSP without having to restart APRS.
      TIME-SYNC - Sync's PC clock to the next GPS report received.  This
      command only sync's to the MINUTE.  Hours are not matched.  Be careful,
      since stand-alone PACCOMM TNC trackers first store the GPS data and then
      later transmit it based on an internal timer, the actual GPS data
      transmitted may not be real-time.  This is true if the GPS loses lock or
      becomes inoperative, (car parked under a tree)  then the TNC continues to
      send the same "old" fix.  If you sync to one of these, you are syncing to
      "old" time!

  P - POSrate - This command is used to set the periodicity for WX, DF and GPS
      reports.  Normally, APRS resets the decay period to an initial 8 second
      period each time you manually change your POSITION report, and then
      doubles the period after each transmission.  This algorithm would
      generate far too many packets from the automatic WX, DF and GPS
      interfaces.  For these interfaces, APRS resets to the period set in the
      POSrate command whenever the data changes.  Actually, this command
      sets two values.  The Refresh rate sets how often the interface is
      sampled just to update the data on your screen, and the POSrate value
      determines how often it is transmitted.
    
  S - SAVE CONFIG FILE - Used to save your current configuration.  Saves
      the current map size and location as well as the state of HF/VHF, and
      your digipeater path.  You will be prompted for your Validation number
      the first time you do a CONFIG file save.  If you have chosen any of
      the GPS, DF or WX options, you will also be prompted for your auxilliary
      registration number as well.  You can save each CFIG file with an
      optional 3 character file extension so that you can call them up quickly
      for different applications.  You invoke the optional files with a /EXT
      switch when you give DOS the APRSxxx command.  IE:  C:> APRS406/MOB would
      load the CFIG406.MOB file which you saved when you operated MOBile.  etc

  T - TNCsetup - sends out TNC commands to setup the TNC for APRS.
      Your TNC is automatically initialized when you start, but can be done
      at any time, if your TNC loses power, or needs to be reset to APRS
      defaults.  When you QUIT APRS, it gives a list of TNC parameters that
      were changed by APRS, and restores any custom commands that you might
      list in the RESTORE.TNC file.

  W - WIDE  Permits an APRS station to override the normal APRS default ALIAS of
      RELAY and set it to the generic WIDE area address so he can serve as
      a temporary WIDE digi.  Do this only with the concurrence of others
      on Frequency.



WEATHER COMMANDS:  APRS displays weather stations as large blue circles with
a white line showing the wind speed and direction.  Remember that APRS uses
360 degrees for North and assumes that 000 means no direction information is
available.  Under the CONTROLs menu, the FILTER command allows you to disable
the POSITION FILTER so that WX reports will be saved to track history files
for trend analysis.  Other WX commands under the WEATHER MENU:

  E - Enter a weather report.  Used to enter a manual WX report.  The word
      (manual) will be added at the end of the report to indicate that it
      was a one time synopsis and that APRS should not update the Date-Time
      each time it is transmitted.

  G - GET NWS SITES - Loads all National Weather Service sites on the present
      map display into the P-list.  This is so that an hourly WX data file
      can be loaded for all all NWS sites listed.

  J - Use the J command to select Just Weather stations for display.

  L - LOAD WX DATA - This key will search a designated file for NWS hourly
      weather advisories.   For each NWS station listed in both the data file
      and already in your P-list, the current conditions will be loaded.  Use
      the G command to pre-load your P-list with the NWS stations near you.

  N - NEXT WX STATION - Highlights the next weather station in turn and
      displays the WX conditions in the weather box at the top of the screen,
      and circles the station on the map for identification.  The Weather box
      at the top of the screen will automatically be updated everytime the
      selected WX station sends out a WX report.

  Q - WEATHER QUERY - Same as QUERY, but only weather stations respond.

  W - WIND - This command is used to set a Wind speed threshold.  Whenever
      the wind exceeds this value, the WX reporting period is reset to the
      minimum POSrate value, for more frequent reporting.
    
TRACKING and TRACK HISTORIES - All position reports are saved to memory and
eventually to file for subsequent replay.  Each new position report is checked
against the last position from that unit and the current values.  If the
POSITION filter is ON (default) then a new position will not be saved to
track history unless movement is more than about 80 yards.  This is to reduce
the number of track points for non-moving stations saved in the file.  The 80
yard circle allows for most of the randomness of GPS Selective Availability
so that parked vehicles do not generate a lot of packets.  If the filter is
OFF, then only a single digit change in a position will generate a new
packet report.  ALso, when the filter is off, ALL WX and DF reports are
saved to file.  This makes it possible to save a DF event, or to keep
historical WX data.  There are several commands related to station tracking:

   T - TRACK - This is a subcommand on the P-list display which allows you to
       designate a station for tracking.  If TRACK is on, then the map will
       always re-center on the selected station whenever it approaches a map
       edge.  This re-centering anticipates the station's movements and
       recenter's the map to give the best next view.

   A - ALARM - This is also a subcommand on the P-list which allows you to set
       an alarm on a given station.  If that station moves, APRS will beep and
       will re-center the map to track that station.  The same filter as used
       on the P-list is also used here so that the randomness of Selective
       Availability does not unnecessarily trigger this alarm.  You can silence
       the beeping by UNHOOKING the station, or by deselecting the ALARM
       function.  Only one ALARM can be set at a time.

   M - MOVE - A subcommand on the P list for moving a station.  Similar to
       just hooking it with the RETURN key, but is the only way to move an
       object or station with 00000/00000  for LAT/LONG.

   S - SAVE FILES - On the FILES MENU, this command forces a save of a BACKUP
       a BLxxxxxx,LOG and a TKxxxxxx.HST file.  If you are in the field, and
       may possibly lose power, do a SAVE now and then, to be sure you save
       all track histories.  After the event, you can use a DOS text editor
       to append all the track history files together for the one event.
       When you Quit APRS, ONLY a Backup file is saved, the LOG and TRACK
       data are LOST!  If, however, you give the BACKUP file any OTHER name,
       then a LOG and TK.HST file ARE saved when you quit.

   REPLAY - Found in both the FILES and OPERATIONS MENUS.  One REPLAYS from
       on-line memory, and the other from a previously saved TRACK file.
       Track histories are retained in memory for instant replay up to 150
       points.  When memory is full, a file is automatically saved and memory
       cleared for more points.  If less than 150 points are in memory, you
       MUST MANUALLY force a save BEFORE exiting the program or the
       track history points in memory will be lost!  During Replay several
       commands are useful to center the screen on the moving object, change
       the speed of replay and zoom in or out, etc.  In version 5.8, the map
       will AUTOTRACK a moving station if only one station is indicated in
       the user response to the TRACK-which-station prompt.
 

DIRECTION FINDING:  APRS can instantly traingulate fixes from many reporting
packet stations, and even show overlapping signal strength contours from
stations with OMNI antennas.  This new OMNI feature is a tremendous advantage,
since it permits the 95% of HAMs who do not have beams or DF gear to partici-
pate in FOX hunts.  The traditional beam-heading reports can either be
automatic from the N7LUE or DSI Doppler serial interfaces, or manual from
other APRS stations. Even stations reporting a beam haeding that are not APRS
equipped, can be placed on the map by any APRS station using the INPUT-ADD
command and be given a beam heading.  APRS assumes that any station or object
using the TRIANGLE symbol is a DF station and will plot a line of bearing if
given.  Note that APRS uses 360 degrees as North and assumes 000 means no
direction information available.  A quality of 8 indicates an excellent fix.
The main DF command is in the OPERATIONS menu.  For more info, see DF.txt.

   SIGNAL STRENGTH - By entering a 0 as a beam heading (APRS uses 360 degrees
       for due north), APRS will assume the report is a signal strength
       report and will prompt you for your antenna height above average
       terrain and antenna gain.  To see the overlapping signal strength
       contours on the map, use the MAP-RINGS-DF command.  APRS will plot
       colored circles around each DF report who's brightness is directly,
       and who's radius is inversly proportional to signal strength. Note
       that you MUST UNDERSTAND what HEIGHT-ABOVE-AVERAGE-TERRAIN means, for
       this to be useful.  If you are getting voice reports, be sure the
       person is giving a true assessment of his HAAT in the general area.
       Or at least in the general direction where the FOX is suspected.

   BEARING - If you enter any other bearing, APRS will prompt you for the
       quality of the fix, and then will plot the bearing from your station.
       heading for your station.  If you are running the WX station option,
       it will be dissabled while the DF report is operative.  You may also
       specify a Quality factor 1-8.  The more dotted the line is, the less
       its quality.

   FADE-CIRCLE TECHNIQUE - This is a new technique in version 5.9 that has
       been used by pilots for locating emergency beacons.  It assumes that
       for any given mobile receiver, there is a unique circle around the
       transmitter where the signal fades out.  All the mobile station has
       to do is plot three points anywhere where the transmitter signal just
       fades in or fades out.  These three points define a circle with the
       transmitter at the center!  APRS implements this technique with single
       keystroke operations.  Each time you press F5, a Fade point is entered
       on the map.

