----------------------------------------------------

                  Courier V.Everything Xmodem SDL Notes

          ----------------------------------------------------

In order to better support users of non-DOS systems, the Courier can now
perform flash ROM updates via the Xmodem file transfer protocol found in
most communications software.

Modems already in the field must first use SDL.EXE to install the new
firmware code as usual.  After installing this SDL, the AT~X! command
will be enabled.  If the flash ROM should ever get corrupted or downgraded,
the Xmodem SDL feature will be lost, and SDL.EXE will have to be used to
return the modem to normal operation.

Modems that come from the factory with this SDL installed will always have
Xmodem SDL available, even in the event of flash corruption or downgrade.

1018828.XMD is the Xmodem mode flash data file.   (This is the same
firmware that is in the SDL.EXE file, but in a different format.) This
is the file that you will send to the modem in Xmodem mode.  The file
supplied with this release is for US/Canada versions of Courier internal,
external, PS/2, and Comserver modems.

          ----------------------------------------------------

          Sending New Firmware to the Courier using Xmodem SDL

          ----------------------------------------------------

1.  Start a communications software package, such as Quick Link II or
    MacComCenter.  Adjust the settings, if necessary, so that you can
    send AT to the Courier and get an OK response.  NOTE:  If you are
    sending the file from a Macintosh computer, make sure that you do
    NOT transfer the file in MacBinary format.  In MacComCenter, for
    example, select Setup -> File Transfer and under MacBinary options,
    select "Never MacBinary."

2.  Type AT~X! <Enter>.  The Courier will respond as follows:


at~x!

SDL Xmodem file transfer - (Y)es (N)o (T)est >


    Responding with 'Y' will begin the file transfer process; responding
    'N' will abort the process and the modem will return to command mode.

    ***********************************************************************
    *                                                                     *
    * Responding with 'T' will begin the file transfer process in a       *
    * "safe test mode".   Test mode will verify the operation of the file *
    * transfer process and the integrity of the .XMD flash data file,     *
    * without actually erasing or re-burning the flash chip.              *
    *                                                                     *
    ***********************************************************************


3.  Respond with 't' to start an integrity test of the XMD file, or
    'y' to begin an actual update of the flash ROM.


SDL Xmodem file transfer - (Y)es (N)o (T)est >t
* Test Mode - Flash ROM will not be modified*
Begin Xmodem file transfer now.
CC


    The Courier will begin sending 'C' characters which are used as part
    of the Xmodem protocol handshaking.

    You may now begin sending the .XMD file to the Courier using the
    XMODEM-CRC or XMODEM-Checksum protocol in your communications software.

4.  After completion of the file transfer, the modem will display a result
    message.


at~x!

SDL Xmodem file transfer - (Y)es (N)o (T)est >t
Begin Xmodem file transfer now.
CC

SDL Xmodem file transfer completed.
Calculating CRC... OK
Resetting modem...OK


    Once you see the OK response to the Calculating CRC and Resetting modem
    messages, your software upgrade is complete, and the modem will reset
    and return to command mode.


          ----------------------------------------------------

                       The Bootstrap Downloader

          ----------------------------------------------------

    If the flash ROM should ever become corrupted, or the modem will not
    respond to Xmodem or SDL.EXE download attempts, follow this procedure to
    activate the flash ROM bootstrap downloader:

1.  Power the Courier off.

2.  Set DIP switches 1, 5, and 10 on and 8 off.  (For internal modems, use
    1, 5, and 10 on, and 7 off.)  The settings of the other DIP switches
    are ignored.

3.  Power the Courier on.

4.  Start your communications software package and send the operating
    software using the XMODEM protocol, or use SDL.EXE as with previous
    versions of the Courier firmware.

5.  Power the Courier off.

6.  Reset the DIP switches to their previous settings.

7.  Power the Courier on.


[End]