SPORTSTER 14,400
                                          CHAPTER 3.  QUICK START
                                                                 
      This chapter provides an overview of
      basic modem settings and is designed to
      quickly get you started using your
      Sportster 14,400.
          If you're already familiar with
           dial-up modems, you may want to
           skip ahead to the Recommended
           Settings section later in this
           chapter.  There you'll find sugges
           tions to help you make the best use
           of the Sportster 14,400.
          If you're a new modem user, the
           next few sections provide some
           general useful information on
           modems.
      Both new and experienced users may want
      to refer to Chapters 4 through 7, as
      well as the Glossary and Index, for
      detailed information on each modem
      feature as well as the terms and
      concepts discussed here.
      
BASIC OPERATING REQUIREMENTS

      For successful data communications to
      occur, your communications software and
      modem require that you set some minimal
      parameters.
      
Software Parameters

      Your communications program requires the
      following parameters.
          The computer or terminal serial
           port to which you've attached the
           modem
          The data rate between the computer
           and modem_also referred to as
           serial port rate_in bits per second
          Parity_usually None or Even
          The number of Stop bits_the final
           bit(s) attached to a data character
           before transmission
          Word length_the number of bits in a
           data character without parity,
           Start and Stop bits
      When the modem receives an AT command
      issued from the keyboard or software,
      it detects the serial port rate and
      data format and uses them as its
      operating parameters.  The remote
      system must use the same word length,
      parity and number of Stop bits.  If you
      don't know what the remote system re
      quires, phone to find out before trying
      to connect via modem.
      
Modem Parameters

      The modem is shipped ready to dial out
      and connect with other modems except
      for Transmit Data flow control.  Don't
      try to make a high-speed call without
      first setting the modem for this
      function.  See the Recommended Settings
      and Alternative Settings sections later
      in this chapter.
      
Setting Modem Parameters

      To change the modem's settings, load
      your communications software and follow
      the procedures your software specifies
      to reconfigure the modem.  Various
      programs may require that you do one of
      the following.
          Insert modem settings in each Dial
           command string in the program's
           Dialing or Phone Directory.
          Create a modem setup string of
           commands.
          Send commands directly to the modem
           (if your program displays a cursor
           on a Terminal screen).
      The following is an example of modem
      parameter settings.
             AT &H1 &B1 <Enter>
      The &H1 command tells the modem to use
      hardware flow control, and &B1 fixes
      the serial port rate at the rate of the
      last AT command.
      
RATE SHIFTING

      The modem has two interfaces at which
      it transmits and receives data:  the
      serial port interface, which it shares
      with the computer or terminal, and the
      phone line interface.
      
Phone Line Interface

      The Sportster 14,400 and compatible
      remote modems go through a connection
      sequence to try to connect at the
      highest possible rate.  As long as your
      software is set to at least 19.2K bps
      and the modem has detected that rate
      through an AT command, the modem is
      always able to connect at 14.4K bps.
      If the remote modem is operating at a
      lower rate, your modem drops its rate
      to connect and the call proceeds at the
      lower rate, for example, 2400 bps.
      This is called the connection rate.
      
Serial Port Interface

      As mentioned earlier, the modem detects
      its operating rate from its last
      received AT command.  After that, the
      modem determines its serial port rate in
      one of the following ways.  Note that in
      both cases, your software must also be
      set to support the same serial port rate
      option.
      1.If the modem and software are set for
         variable serial port rates, both the
         modem and the software shift their
         port rates to match any rate
         switching at the phone line
         interface.
         If the modem connects with a remote
         modem at 2400 bps, for example, you
         will find after your call that your
         software setting has switched down to
         2400.  If you want to dial out at
         9600 bps, change the software setting
         first, before instructing the modem
         to dial.
      2.If the modem and software are set for
         a fixed serial port rate, the rate at
         the serial port does not drop down to
         match a lower connection rate.  This
         allows you to lock in a higher rate
         at the port (for example, 38.4K or
         19.2K bps) for very efficient
         transmission between the modem and
         the terminal.
      You'll find instructions in the
      following section, Recommended
      Settings.  If your software supports a
      fixed serial port rate, you will
      achieve greater throughput with this
      option.  Particularly if the modems
      connect under data compression, a
      fixed, high serial port rate can more
      than triple the amount of data that
      goes from one computer to the other
      each second, and keep your phone line
      costs to a minimum.
      
RECOMMENDED SETTINGS

      We recommend using all of the modem's
      factory settings except for flow control
      and the serial port rate.  Flow control
      is factory-set as disabled; we recommend
      that you enable hardware flow control.
      The serial port rate is factory-set as
      variable; we recommend that you set a
      fixed, high serial port rate (as
      described above).  Note that to use
      these recommended settings, your machine
      and software must also support them.
      Check the quick configuration guide that
      came with the modem to see if your
      communications program is listed and
      what it supports.  If your program is
      not listed, review your software
      documentation.  If the software doesn't
      support either hardware flow control or
      a fixed rate at the computer interface,
      review Alternative Settings, after this
      section.
      Check your software or terminal
      documentation to see if your machine
      supports the recommended settings.
      Apple computers, for example, do not
      support a fixed serial port rate or
      hardware flow control (Clear to
      Send/Request to Send signaling).
   Software Settings
      Hardware flow control: Select your
      software's option for hardware flow
      control. Many programs combined CTS/RTS
      as one option.
      NOTE:  All 100% IBM-compatible computers
      support hardware flow control.  Some
      software supports both hardware and
      software flow control, but requires you
      to turn off the kind you're not using.
      Check your software manual.
      38.4K or 19.2K bps:  Set a high data
      rate between the modem and the computer.
      A rate of 19.2K bps is required to make
      a 14.4K bps connection, however 38.4K
      bps provides the greatest efficiency
      when a call is under error control and
      data compression.
      NOTE: If you are certain that your
      software, computer, and serial card (if
      you have one) can handle 57.6K bps, you
      can use this higher speed.  We recommend
      that you use this speed only if
      necessary; you could lose data if part
      of your system can't handle 57.6K bps.
      If you're not sure of your system's
      capabilities, use 38.4K bps, which is
      efficient and reliable.
      Fixed Rate:  Many programs that support
      a fixed serial port rate control this
      function with an Auto Baud Detect
      toggle.  Toggle Auto Baud Detect OFF and
      the software data rate will remain high,
      even if the phone connection is as low
      as 300 bps.  If your software calls this
      Locking the Port Speed, select this
      option.
   Modem Settings
      &H1  Clear to Send Hardware flow
            control:  the modem sends CTS
            signals to the computer or
            terminal to control the data
            flow.  Flow control is required
            for error control and when the
            serial port rate is higher than
            the connection rate.  (The &H2
            setting, software flow control,
            may affect data reliability.  See
            Example 2 in the next section,
            Alternative Settings.)
      &R2  Request to Send hardware flow
            control:  the computer or
            terminal sends RTS signals to the
            modem to control the data flow.
      &B1  The modem's serial port rate is
            fixed at the rate of the last AT
            command.  It does not switch to
            match the phone connection rate
            when the modem connects with a
            remote modem at a lower rate.
            Your software must first be set
            to a fixed rate, as shown under
            the previous heading, Software
            Settings.
            
      If your software supports the &H1, &R2
      and &B1 options, we recommend that you
      make them your power-on and reset
      defaults by writing them to nonvolatile
      memory.  See Page 3-9.
      NOTE:  The next section, Alternative
      Settings, shows how to set the modem if
      your software does not support the
      above options.  Also included are
      recommended settings if you will
      normally use software flow control but
      plan to use an Xmodem-type protocol,
      and guidelines on transferring files
      that are already compressed.
      
ALTERNATIVE SETTINGS

      1.Your software doesn't support Clear
         to Send, but supports XON/XOFF
         signaling.
         &H2  Software flow control:  the
               modem sends Ctrl-S and Ctrl-Q
               (XOFF/XON) characters to the
               computer or terminal to control
               the flow of data.
         &B1  As above, under Recommended
               Settings, providing your
               software supports a fixed
               serial port rate.
       WARNING:  Software flow control is not
        recommended because Ctrl-S or Ctrl-Q
        characters that occur in a file, or
        in a file transfer protocol such as
        Zmodem, may be misinter-preted and
        dropped from the data stream by the
        modem or receiving computer.  Set the
        modem to &H2 or &H3 only if you are
        transferring text files.
      2.Your machine or software doesn't
         support Clear to Send, and you're
         using an Xmodem-type file-transfer
         protocol.
         &H0  Factory setting.  Flow control
               disabled.  Do not use software
               flow control (&H2), because the
               protocol uses the Ctrl-S and
               Ctrl-Q characters that will be
               misinterpreted as flow control
               characters, and you risk losing
               data.
         &B0  Factory setting.  The serial
               port rate switches to match the
               connection rate of each call.
               Recommended because there is no
               flow control.  Be sure also to
               set your communications
               software to switch its rate.
               Turn ON the Auto Baud Detect
               option, unlock the serial port,
               or select whatever setting the
               program requires.
         &M0  Error control disabled;
               recommended because there is no
               flow control.
         CAUTION:  Many Xmodem-type protocols
         are available.  However, keep the
         following limitations in mind.
          Most of these protocols perform
           error control, which makes them
           safe for calls at all rates from
           14.4K down to 300 bps.  Ymodem-G,
           however, should not be used with
           the above modem settings, because
           its response to errors is to abort
           the call.  Earlier versions of
           Zmodem did not perform error
           control and should also be avoided.
           Current versions of Zmodem,
           however, are highly recommended.
           See Throughput Guidelines in
           Chapter 4 or appendix A for more
           guidelines.
          Because flow control is disabled,
           the data packets transferred by the
           protocol should be less than 1,000
           bytes in size, and should not be of
           the sliding-window type.  Review
           the protocol documentation before
           using the protocol.  If the packets
           are too large, and there is no flow
           control, you risk losing data.
      3.Your system doesn't support either
         Clear to Send or XON/XOFF signaling.
         &H0  Factory setting.  Flow control
               disabled.
         &B0  Factory setting.  The serial
               port rate switches to match the
               connection rate of each call.
               Required because there is no
               flow control.
         &M0  Error control disabled,
               required because there is no
               flow control.
         CAUTION:  We recommend that the modem
         settings just described never be used
         for calls above 2400 bps unless
         you're using an error-control file-
         transfer protocol.  See the
         cautionary notes under Example 2.
      4.Your software does not support a
         fixed rate at the serial port
         interface.
         &B0  Factory setting, variable
               serial port rate:  this rate
               switches to match the
               connection rate of each call.
               This does not affect error
               control or flow control.
              NOTE:  You will not gain the
               throughput efficiency that
               occurs when the serial port
               rate is fixed at a higher rate
               than the connection rate.  In
               addition, at the factory
               setting for data compression,
               &K1, the modem disables
               compression when the connection
               rate is set to &B0.  When the
               serial port and connection
               rates are equal, data
               compression gives no advantage.
               In fact, data compression
               operations add time to the
               call.
      5.You are calling a non-MNP modem.
         S27=16Disable MNP handshaking.  A non-
               MNP modem may misinterpret the
               MNP link request and prevent a
               successful connection.  If the
               remote modem uses V.42 error
               control, the modems will
               connect under V.42 error
               control.  Otherwise, they
               connect without any error con
               trol.  Note that this applies
               only if you are calling a non-
               MNP modem.
      6.You are transferring already
         compressed files.
         &K3  This disables MNP compression,
               which does not work
               successfully with files that
               are already compressed.  If the
               remote modem is able to use
               V.42 bis compression, you will
               gain optimal throughput.
               
DATA FORMAT

      Your communications software and the
      remote communications software must be
      set to the same word length, parity, and
      number of Stop bits.  Information
      Services and Bulletin Boards make this
      information readily available.  If you
      don't know what the remote system
      requires, phone first to find out.  If
      you have trouble connecting with a
      remote system, the reason may be the
      wrong word length/parity/Stop bit
      combination.
      The Sportster modem is set at the
      factory to a 7-bit word length, even
      parity, and 1 Stop bit.  Some
      communications programs use a shorthand
      method to refer to this format:  7-E-1.
      If you wish to call a remote system that
      requires a different format, set your
      software to the correct parameters
      before you attempt to dial out.  When
      the modem receives the dial command, it
      detects the new data format from the AT
      command prefix.
      One Start bit is universal and not
      programmable.  The other allowable
      options are listed in the following
      table; with the Start bit they form a
      ten-bit data unit.
      
           Table 3.1_Allowable Data Formats
                       
            Word    Parity    Stop
           Length  (1 Bit)    Bits
             7    Even, Odd,   1
                 Mark, Space
             7       None      2
             8       None      1
           
STORING DEFAULTS IN NONVOLATILE MEMORY

      Write your default configuration to
      nonvolatile memory (NVRAM) with the &W
      command.  First, set your software to
      the desired communications parameters,
      for example:
         Serial port rate    38.4K bps
         Word length 8
         Parity      None
         Stop bits   1
      The following command example sets the
      modem for the current session, and
      stores the settings inserted before &W
      as defaults.  These include the above
      parameters that the modem detects from
      the rate and format of the AT command
      prefix.
             AT &B1 &H1 &W <Enter>
      As long as DIP switch 7 is UP (OFF), the
      modem loads the defaults from NVRAM at
      power-on and reset, including the rate
      and format defaults.  Be sure to type &W
      last in the string, before pressing the
      Enter key.
DIALING

      Use the following command format,
      beginning with the AT prefix and issued
      by pressing <Enter>.  The maximum number
      of characters in a command string is 40.
      The modem defaults to pulse dialing:
      the T in the command enforces tone
      dialing.
             ATDT phonenumber <Enter>
      To redial the number, you can use the
      repeat command.
             A/ <Enter>
      This command causes the modem to re-
      execute the command in the command
      buffer.  If you've sent an additional
      command to the modem, that command now
      occupies the buffer.

