


                                    MULTICOMM
                             OPERATING INSTRUCTIONS
                                  Version  2.00



         MULTICOMM  software  enables  the IBM Personal Computer to support
     ASCII,   RTTY  (radio  teleprinter)  and  MORSE  CODE  communications.
     Telephone communication requires a standard modem connected to the IBM
     PC serial  port.  Radio communication is possible when a terminal unit
     with an RS-232 interface is connected to the IBM PC serial port. Morse
     Code support is limited to transmission only.

         The program operates in two different modes. The MENU mode is used
     to  select terminal  parameters  or options.  The TERMINAL mode is for
     communications.









                            INITIAL PROGRAM DEFAULTS

              =====================================================

                       SPEED --------------------  60 Baudot
                       SERIAL PORT --------------  COM1
                       PARALLEL PORT ------------  LPT1
                       ECHO ---------------------  ON
                       FILTER -------------------  OFF
                       UNSHIFT ON SPACE ---------  ON
                       RELAY --------------------  OFF
                       BELL ---------------------  ON









                           OPERATION IN THE MENU MODE


         Select  the  MENU  mode  by pressing the ESC key from the terminal
     mode.  The  current  operating parameters are displayed in highlighted
     video. You can quickly make changes by pressing the key corrresponding
     to a new choice.  MULTICOMM lets you enable this change immediately by
     pressing the ENTER key, or make additional selections.  When the ENTER
     key  is pressed, all of the highlighted parameters go into effect, the
     menu  screen  clears  and  the system reverts to the terminal mode for
     communications.

         Pressing  the  ESC  key in the MENU mode will void any selections,
     and  return  to  the  terminal  mode  with the old parameters still in
     effect.  In the MENU mode, incoming data  is stored in the Comm Buffer
     and will be dumped to the screen when you return to the terminal mode.
     To return to DOS from the Menu mode, press the END key.







                                     SPEEDS

         Available  speed  selections  are shown with the current operating
     speed in highlighted video.  To select another speed in the MENU mode,
     press the function key that corresponds to the new speed.


        "F1"   Baudot,  45 baud, 5 data bits, Parity none, 2 stop bit(s)
        "F2"   Baudot,  50 baud, 5 data bits, Parity none, 2 stop bit(s)
        "F3"   Baudot,  65 baud, 5 data bits, Parity none, 2 stop bit(s)
        "F4"   Baudot,  74 baud, 5 data bits, Parity none, 2 stop bit(s)
        "F5"   ASCII,  110 baud, 7 data bits, Parity even, 2 stop bit(s)
        "F6"   ASCII,  300 baud, 7 data bits, Parity even, 1 stop bit(s)
        "F7"   ASCII, 1200 baud, 7 data bits, Parity even, 1 stop bit(s)
        "F8"   ASCII, 2400 baud, 7 data bits, Parity even, 1 stop bit(s)
        "F9"   Morse Code, Transmit speed as shown.
        "F10"  Morse Code, Set transmit speed between 5 and 95 wpm.








                                    SWITCHES

       These features are turned ON or OFF by pressing the associated key.

         "E" ECHO -------------   ON=Half Duplex, OFF=Full Duplex (ASCII)

         "F" FILTER -----------   Discard extraneous incoming characters

         "U" UNSHIFT ON SPACE -   Reset to letters case on space (Baudot)

         "R" RELAY ------------   Close cassette relay on PTT or Morse Code

         "B" BELL -------------   Sound incoming character or margin bell













                                      PORTS

         These ports may be selected by pressing the associated key.

              "C"  COM1/COM2 --------  Serial Communications Port.

              "L"  LPT1/LPT2/LPT3 ---  Parallel Printer port.














                              SYSTEM CONFIGURATION

         COMM BUFFER ------  The amount of free space remaining in the
                             receive buffer.  As this free space drops
                             below 128 characters, "Comm Buffer" will
                             flash as a warning.

         RAM --------------  The amount of system Random Access Memory
                             available.

         TIME -------------  The time adjusted to the user selected
                             offset.













                                  FUNCTION KEYS


         Function   key   messages   are   assigned  by  pressing  the  "A"
     (Assignment) key in the MENU mode.

         Function  key  Directories  are  displayed  by  pressing  the  "D"
     (Directories) key in the MENU mode.














                                DEFAULT SETTINGS

         To  create  a  default  setup  file,  select  the parameters to be
     stored, then press "W" (Write). The highlighted values will be written
     to  the  MCOMM.SET file. MULTICOMM will load these parameters on start
     up.

         To  reload  the  default values stored on disk, press and hold the
     Ctrl key  then  press the ENTER key.  The parameters will be read from
     the MCOMM.SET file and loaded into the program.












                         OPERATION IN THE TERMINAL MODE


         In the TERMINAL mode, characters typed on the keyboard are sent to
     the  selected  serial  port  for  transmission to the terminal unit or
     modem.  Data coming in from the terminal unit or modem is displayed on
     the  screen.

         Pressing  the  ESC  key in the TERMINAL mode will cancel your last
     command  or  display the main menu. To return to DOS from the terminal
     mode, press the END key.













                               STATUS LINE DISPLAY

         A Speed Status Line appears at the bottom of the screen to display
     the  current  SPEED  and  FILTER  status  as well as: F1=Function Keys
     ESC=Menu  HOME=Help  END=Exit.  Pressing the F1 key toggles line 25 to
     the  Function  Key  Status  Line,  which  displays  abbreviated F1-F10
     function key assignments.












                                    PRINTOUT

         MULTICOMM  allows  the  printout of incoming data, as well as data
     generated  from  the  keyboard. The F2 key toggles the printout ON and
     OFF.  The  blinking  "PRINT" on the Function Key Status Line indicates
     the  printout is active. A line is printed each time a carriage return
     occurs or a line contains 80 characters.

          The   printout   is   automatically   terminated   under  certain
     conditions.  For  example,  if  you  select  a  printer port without a
     printer,  the  program  will  pause about 30 seconds, no incoming data
     will go to the screen and keyboard data is ignored. At the end of this
     interval "Printer  Unavailable!" appears in highlighted video.  If the
     data  rate  is  too fast for the printer to keep up with, the printout
     will be turned off to prevent incoming data from being lost.










                                RECEIVING A FILE

         Received  data  is  stored  on  disk by pressing the F3 key in the
     terminal  mode.  A highlighted prompt will appear on the screen. Enter
     the filename you want the data to be stored under. For example, if you
     are  receiving  the  UPI  news  service  you  may store it as "PRESS",
     "PRESS.TXT",  "A:PRESS.UPI" or any valid DOS filename. A blinking "RX"
     on the Function Key Status Line indicates file reception is active.

        To terminate,  press the F3 key in the terminal mode.   The receive
     buffer contents will be written to disk, and file reception ended.














                               TRANSMITTING A FILE

         Select  file  transmission  by pressing the F4 key in the terminal
     mode.  A highlighted prompt asks for the name of the file to transmit.
     When  transmission  begins, line 25 is replaced by a File Transmission
     Status  Line,  to show the number of remaining 128 character blocks to
     be sent. Press the F4 key to terminate the transmission.
















                                 VIEWING A FILE

         It is  possible  to view any ASCII file by pressing the F5 key.  A
     highlighted  prompt  requests the file to be viewed. Type the filename
     and  press  ENTER, the file will scroll on the screen and pause, press
     the  SPACEBAR  to  continue  viewing.  Press  the  F5 key to terminate
     viewing.  Data coming in while viewing a file is stored in the receive
     buffer  and  will  be  printed  to the screen when the file viewing is
     ended.















                                 ERASING A FILE

         You need  not  exit  to DOS to erase a file.  Press the F6 key and
     specify  the  filename to be erased. A prompt asks for confirmation to
     erase  the  file. If you answer "Y" (Yes) the file is erased and lost.
     Any other response will cancel the procedure.

















                              CAPTURING SCREEN DATA

         A  copy  of  the terminal screen may be stored on disk even though
     the file receive mode is not active. Press the F7 key, data is written
     to a file called SCREEN.DAT, a tone sounds, and the program reverts to
     the terminal mode.
















                             SENDING A BREAK SIGNAL

         A  break  is  the  transmission of a continuous space signal for a
     period  of time. In communications between two computers the signal is
     sent  as  an  interrupt to the other computer to stop its transmission
     and  listen  for data. In radio communications the break signal can be
     used  to  test  the space tone transmitted by the terminal unit. Press
     the  F8 key in the terminal mode to send a 1/2 second break signal. In
     Morse Code the proword "BT" will be sent.
















                               CLEARING THE SCREEN

         Clear the screen in the terminal mode by pressing the F9 key. This
     function does not erase the status line at the bottom of the screen.

















                                 ACTIVATING PTT

         Pressing  the  F10 key in the terminal mode toggles the PTT signal
     ON and  OFF  for  use  with  a  radio  transmitter.  When "PTT" on the
     Function  Key  Status Line is flashing, the RTS (Ready to Send) signal
     at the selected serial port is activated.  If the RELAY function is ON
     the  relay  contacts  will  be closed. In Morse Code operation the RTS
     signal   is  activated,  but  not  the  relay, since  it  operates  in
     conjunction with the tone output for each character.













                      CHANGING SPEEDS IN THE TERMINAL MODE

         Speed  changes  are  made from the terminal mode by first pressing
     and  holding  the  Alt  key  then  pressing  an  F1  through  F10  key
     corresponding  to  the speed selection function keys in the main menu.
     For example, Alt F1=60 wpm Baudot, Alt F2=66 wpm Baudot, Alt F3=75 wpm
     Baudot,  etc.  A list of the speed assignments appears in the function
     key directory.
















                     TOGGLING SWITCHES IN THE TERMINAL MODE

        Switches  are  toggled from the terminal mode by first pressing and
     holding  the Alt key then pressing the key corresponding to the switch
     selection key in  the main menu.  For example, Alt "E" will toggle the
     Echo feature, Alt "F" will toggle the Filter, etc.

















                               PREDEFINED MESSAGES

         You  can  send  predefined  messages in the terminal mode by first
     pressing and holding down the Ctrl key then pressing an F1 through F10
     key corresponding to the message to be sent. The messages are assigned
     by  selecting  Alt  "A" in the terminal mode which displays a Function
     Key  Assignment  Screen  for  entering  messages. A directory of these
     messages  is  available by pressing Alt "D" from the terminal mode and
     continuing to page 2.














                                  RELAY WIRING

         The  cassette  motor  control  relay  on the IBM PC can be used to
     control  the  Push  To  Talk  or  CW  (Morse  Code)  Key  circuit of a
     transmitter.  The  relay  contacts appear on pins 1 and 3 of the 5-Pin
     DIN  connector  on  the  back  of  the  computer.  The  relay  can  be
     deactivated by switching the RELAY function off from the menu.












                                  RS-232 WIRING

         MULTICOMM  disables  the  Clear  To  Send  signal  to simplify the
     connections  between  the IBM Personal Computer and the terminal unit.
     Feed  the  audio  signal  from  your  radio into the terminal unit and
     follow  the  manufacture's  instructions, or those below for wiring to
     the computer's serial port.

           IBM PC RS-232 PORT                      TERMINAL UNIT RS-232
           ------------------                      --------------------

           Pin 1  Ground              to           Pin 1  Ground
           Pin 2  TX data             to           Pin 3  Data in
           Pin 3  RX data             to           Pin 2  Data out
           Pin 7  Signal ground       to           Pin 7  Signal ground
           Pin 20 Ready To Send       to           Pin 20 PTT control




                                 TERMINAL UNITS


         A  terminal  unit  is  a  modem  designed  to  operate  with radio
     communications  equipment and employs standard audio frequency shifts.
     The  shift is the difference in the audio frequencies between the mark
     and the space signals. Amateur RTTY communications, for the most part,
     is  standardized at 170 Hz shift. Other shifts are 850 Hz (used by the
     weather  bureau)  and 425 Hz (used by many commercial press stations.)
     On  a  single  sideband  radio the receiver BFO allows you to tune the
     frequency  over  a  wide  range  of  audio  tones, but the audio shift
     between  the  two tones will remain constant regardless of the carrier
     frequency.  Most  terminal units use 2125 Hz as the MARK tone with the
     SPACE  tone  up  in  frequency  by  the  ammount  of shift being used.
     Additional audio filtering is used so that reliable communications may
     be  carried  on  in  the  noisy conditions found on the high frequency
     radio  bands.

         Terminal  units  generally  incorporate  circuitry  to  detect the
     presence  of a valid RTTY signal in order to make unattended operation
     possible.  This  process  is known as "autostart" and prevents garbage
     from being printed by random noise signals.




                             RECEIVING RTTY SIGNALS

         Receiving  RTTY signals can be confusing. Many RTTY signals on the
     high frequency bands are encrypted, or are in a foreign language using
     other  than  the latin alphabet. We recommend you begin RTTY listening
     in  the  amateur bands. Here you will find signals most of the time as
     well  as  a  known shift and speed. Most amateur RTTY occurs at 60 wpm
     Baudot  using  170  Hz shift and is centered between 14.075 and 14.100
     Mhz.  Set your HF receiver on lower sideband and slowly tune in a RTTY
     signal  following  the  instructions for your terminal unit. MULTICOMM
     software and your IBM PC will do the rest.





                               Copyright (C) 1984
                        MULTICOMM COMMUNICATIONS SOFTWARE
                     1806 Foxwood Drive, Houston Texas 77008
