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

   US ROBOTICS 2400

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

<gopher://bitreich.org/I/th99/t/0-9/54129-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |     Purpose      | Location |      Purpose      | Location |
   |------------------+----------+-------------------+----------|
   | Line out         |   CN1    | Power in          |   CN4    |
   |------------------+----------+-------------------+----------|
   | Line in          |   CN2    | Volume            |    R1    |
   |------------------+----------+-------------------+----------|
   | RS-232/422       |   CN3    | Power switch      |   SW2    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     DIAGNOSTIC LED(S)                      |
   |------------------------------------------------------------|
   | LED  | Color |  Status  |            Condition             |
   |------+-------+----------+----------------------------------|
   | LED1 |  Red  |    On    |  Analog loopback self test mode  |
   |------+-------+----------+----------------------------------|
   | LED1 | Green |    On    |            Data mode             |
   |------+-------+----------+----------------------------------|
   | LED2 |  Red  | Blinking | Modem is transmitting/receiving  |
   |      |       |          |               data               |
   |------+-------+----------+----------------------------------|
   | LED2 | Green |    On    |     Carrier signal detected      |
   +------------------------------------------------------------+

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

   +------------------------------------------------------------+
   |                        RESULT CODES                        |
   |------------------------------------------------------------|
   | Setting                   |             SW1/2              |
   |---------------------------+--------------------------------|
   |>> Off                     | Extended result codes enabled  |
   |---------------------------+--------------------------------|
   | On                        | Extended result codes disabled |
   +------------------------------------------------------------+

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

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

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

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

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

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

                     Proprietary AT Command Set

   +------------------------------------------------------------+
   |                        TIME DISPLAY                        |
   |------------------------------------------------------------|
   | Type:        | Immediate                                   |
   |--------------+---------------------------------------------|
   | Format:      | AT [cmds] Kn [cmds]                         |
   |--------------+---------------------------------------------|
   | Example:     | AT K1 *L2 #E1<CR>                           |
   |--------------+---------------------------------------------|
   | Description: | Displays the current call time or clock     |
   |              | time.                                       |
   |--------------+---------------------------------------------|
   |   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] >                                 |
   |--------------+---------------------------------------------|
   | Example:     | AT DT1(303) 443-3388 > <CR>                 |
   |--------------+---------------------------------------------|
   | Description: | Causes modem to repeat command string until |
   |              | a keyboard key is pressed.                  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 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.           |
   +------------------------------------------------------------+