3COM CORPORATION
================

   US ROBOTICS 2400PC

   Modem Type               Data (synchronous/asynchronous)       
   Maximum Data Rate        2400bps                               
   Data Bus                 8-bit ISA                             
   Fax Class                Class I & II                          
   Data Modulation Protocol Bell 103A/212A                        
                                                                  
                            ITU-T V.21, V.22                      

<gopher://bitreich.org/I/th99/t/0-9/54128-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |      Purpose      | Location |     Purpose      | Location |
   |-------------------+----------+------------------+----------|
   | Line out          |   CN1    | Volume           |   SW2    |
   |-------------------+----------+------------------+----------|
   | Line in           |   CN2    |                  |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                         DTR SIGNAL                         |
   |------------------------------------------------------------|
   | Setting                       |           SW1/1            |
   |-------------------------------+----------------------------|
   |>> DTR forced high             |             On             |
   |-------------------------------+----------------------------|
   | DTR normal                    |            Off             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        RESULT CODES                        |
   |------------------------------------------------------------|
   | Setting                       |           SW1/2            |
   |-------------------------------+----------------------------|
   |>> Verbal result codes enabled |            Off             |
   |-------------------------------+----------------------------|
   | Numeric result codes enabled  |             On             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    RESULT CODES DISPLAY                    |
   |------------------------------------------------------------|
   | Setting                       |           SW1/3            |
   |-------------------------------+----------------------------|
   |>> Display disabled            |             On             |
   |-------------------------------+----------------------------|
   | Display enabled               |            Off             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        ECHO DISPLAY                        |
   |------------------------------------------------------------|
   | Setting                       |           SW1/4            |
   |-------------------------------+----------------------------|
   |>> Local echo enabled          |            Off             |
   |-------------------------------+----------------------------|
   | Local echo disabled           |             On             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        AUTO ANSWER                         |
   |------------------------------------------------------------|
   | Setting                               |       SW1/5        |
   |---------------------------------------+--------------------|
   |>> Modem does not answer on first ring |         On         |
   |---------------------------------------+--------------------|
   | Modem answers on first ring           |        Off         |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                       CARRIER DETECT                       |
   |------------------------------------------------------------|
   | Setting                       |           SW1/6            |
   |-------------------------------+----------------------------|
   |>> CD normal                   |            Off             |
   |-------------------------------+----------------------------|
   | CD forced high                |             On             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                MULTIPLE PHONE INSTALLATION                 |
   |------------------------------------------------------------|
   | Setting                       |           SW1/7            |
   |-------------------------------+----------------------------|
   |>> Single phone connected      |            Off             |
   |-------------------------------+----------------------------|
   | Multiple phones connected     |             On             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                       AT COMMAND SET                       |
   |------------------------------------------------------------|
   | Setting                       |           SW1/8            |
   |-------------------------------+----------------------------|
   |>> AT command set recognized   |             On             |
   |-------------------------------+----------------------------|
   | AT command set disabled       |            Off             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        ESCAPE CODE                         |
   |------------------------------------------------------------|
   | Setting |                      SW1/9                       |
   |---------+--------------------------------------------------|
   |>> On    |  Go to command mode and display OK result code   |
   |         |        when escape character is received         |
   |---------+--------------------------------------------------|
   | Off     |  Disconnect, go to command mode and display NO   |
   |         |    CARRIER when escape character is received     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                FACTORY CONFIGURED SETTINGS                 |
   |------------------------------------------------------------|
   |           Switch            |           Setting            |
   |-----------------------------+------------------------------|
   |           SW1/10            |           Not used           |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   COM PORT CONFIGURATION                   |
   |------------------------------------------------------------|
   |       Port       |         J1         |         J2         |
   |------------------+--------------------+--------------------|
   |   COM1: (3F8h)   | Pins 1 & 2 closed  | Pins 1 & 2 closed  |
   |------------------+--------------------+--------------------|
   |   COM2: (3E8h)   | Pins 3 & 4 closed  | Pins 1 & 2 closed  |
   |------------------+--------------------+--------------------|
   |   COM3: (2F8h)   | Pins 1 & 2 closed  | Pins 3 & 4 closed  |
   |------------------+--------------------+--------------------|
   |   COM4: (2E8h)   | Pins 3 & 4 closed  | Pins 3 & 4 closed  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    INTERRUPT SELECTION                     |
   |------------------------------------------------------------|
   |            IRQ             |              J3               |
   |----------------------------+-------------------------------|
   |             3              |       Pins 3 & 5 closed       |
   |----------------------------+-------------------------------|
   |             4              |       Pins 1 & 3 closed       |
   |----------------------------+-------------------------------|
   |             5              |       Pins 2 & 4 closed       |
   |----------------------------+-------------------------------|
   |             7              |       Pins 4 & 6 closed       |
   |----------------------------+-------------------------------|
   |          Disabled          |             Open              |
   +------------------------------------------------------------+

                     Proprietary AT Command Set

   +------------------------------------------------------------+
   |                 ANALOG LOOPBACK SELF TEST                  |
   |------------------------------------------------------------|
   | Type:        | Register                                    |
   |--------------+---------------------------------------------|
   | Format:      | AT [cmds] S16=n [cmds]                      |
   |--------------+---------------------------------------------|
   | Example:     | ATS16=139<CR>                               |
   |--------------+---------------------------------------------|
   | Description: | Selects the tone dialing test.              |
   |--------------+---------------------------------------------|
   | Command      |                  Function                   |
   |--------------+---------------------------------------------|
   |      0       | Data mode.                                  |
   |--------------+---------------------------------------------|
   |      1       | Analog loopback.                            |
   |--------------+---------------------------------------------|
   |      2       | Dial testing.                               |
   |--------------+---------------------------------------------|
   |      4       | Test pattern.                               |
   |--------------+---------------------------------------------|
   |      5       | Analog loopback and test pattern.           |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                       CLOCK DISPLAY                        |
   |------------------------------------------------------------|
   | Type:        | Configuration                               |
   |--------------+---------------------------------------------|
   | Format:      | AT [cmds] Kn [cmds]                         |
   |--------------+---------------------------------------------|
   | Example:     | AT K1 *L2 #E1<CR>                           |
   |--------------+---------------------------------------------|
   | Description: | Automatically establishes switched line     |
   |              | connection if leased line fails             |
   |--------------+---------------------------------------------|
   |   Command    |                  Function                   |
   |--------------+---------------------------------------------|
   |      K0      | Display length of last call.                |
   |--------------+---------------------------------------------|
   |      K1      | Display actual time.                        |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        HELP SCREENS                        |
   |------------------------------------------------------------|
   | Type:        | Immediate                                   |
   |--------------+---------------------------------------------|
   | Format:      | AT <prefix>$                                |
   |--------------+---------------------------------------------|
   | Example:     | AT &$<CR>                                   |
   |--------------+---------------------------------------------|
   | Description: | Shows command help screens for all commands |
   |              | beginning with the given prefix, or no      |
   |              | prefix if none is given.                    |
   |--------------+---------------------------------------------|
   |   Command    |                  Function                   |
   |--------------+---------------------------------------------|
   |      $       | Shows ATx help screen.                      |
   |--------------+---------------------------------------------|
   |      D$      | Shows ATDx help screen.                     |
   |--------------+---------------------------------------------|
   |      S$      | Shows S-register help screen.               |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   REPEAT COMMAND STRING                    |
   |------------------------------------------------------------|
   | Type:        | Configuration                               |
   |--------------+---------------------------------------------|
   | Format:      | AT [cmds] > [cmds]                          |
   |--------------+---------------------------------------------|
   | Example:     | AT *D1 > #E1<CR>                            |
   |--------------+---------------------------------------------|
   | Description: | Causes modem to repeat command string until |
   |              | a keyboard key is pressed.                  |
   +------------------------------------------------------------+