(TXT) View Source
       
       # 3COM CORPORATION
       
          VARMODEM 1200
       
          Modem Type               Data (synchronous/asynchronous)       
          Maximum Data Rate        1200bps                               
          Data Bus                 8-bit ISA                             
          Data Modulation Protocol Bell 103A/212A                        
                                                                         
                                   ITU-T V.21, V.22                      
       
 (IMG) IMG 1
          
       
          +------------------------------------------------------------+
          |                        CONNECTIONS                         |
          |------------------------------------------------------------|
          |      Purpose      | Location |     Purpose      | Location |
          |-------------------+----------+------------------+----------|
          | Line out          |   CN1    | Volume           |    R1    |
          |-------------------+----------+------------------+----------|
          | Line in           |   CN2    |                  |          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  MULTI-LINE INSTALLATION                   |
          |------------------------------------------------------------|
          | Setting                       |             J1             |
          |-------------------------------+----------------------------|
          | » Single modem                |            Off             |
          |-------------------------------+----------------------------|
          | Multi-line                    |             On             |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    TRANSMISSION FORMAT                     |
          |------------------------------------------------------------|
          | Setting                       |             J2             |
          |-------------------------------+----------------------------|
          | » 10-bit                      |            Off             |
          |-------------------------------+----------------------------|
          | 11-bit                        |             On             |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                           RESET                            |
          |------------------------------------------------------------|
          | Setting                       |            J14             |
          |-------------------------------+----------------------------|
          | » Enabled                     |            Off             |
          |-------------------------------+----------------------------|
          | Disabled                      |            N/A             |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                FACTORY CONFIGURED SETTINGS                 |
          |------------------------------------------------------------|
          |            Jumper            |           Setting           |
          |------------------------------+-----------------------------|
          |              J3              |             On              |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 BASE I/O ADDRESS SELECTION                 |
          |------------------------------------------------------------|
          |        Port        |        J10         |       J11        |
          |--------------------+--------------------+------------------|
          |    COM1: (3F8h)    | Pins 2 & 3 closed  |       Off        |
          |--------------------+--------------------+------------------|
          |    COM2: (2F8h)    | Pins 2 & 3 closed  |        On        |
          |--------------------+--------------------+------------------|
          |    COM3: (3E8h)    | Pins 1 & 2 closed  |       Off        |
          |--------------------+--------------------+------------------|
          |    COM4: (2E8h)    | Pins 1 & 2 closed  |        ON        |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    INTERRUPT SELECTION                     |
          |------------------------------------------------------------|
          |            IRQ             |              J12              |
          |----------------------------+-------------------------------|
          |             3              |       Pins 2 & 3 closed       |
          |----------------------------+-------------------------------|
          |             4              |       Pins 1 & 2 closed       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        AUTO ANSWER                         |
          |------------------------------------------------------------|
          | Setting              |                SW1/1                |
          |----------------------+-------------------------------------|
          | » Off                |     Modem answers on first ring     |
          |----------------------+-------------------------------------|
          | On                   | Modem does not answer on first ring |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                       CARRIER DETECT                       |
          |------------------------------------------------------------|
          | Setting                    |             SW1/2             |
          |----------------------------+-------------------------------|
          | » Off                      |           CD normal           |
          |----------------------------+-------------------------------|
          | On                         |        CD forced high         |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                          PBX MODE                          |
          |------------------------------------------------------------|
          | Setting                 |              SW1/3               |
          |-------------------------+----------------------------------|
          | » Off                   | Normal dial up line equalization |
          |-------------------------+----------------------------------|
          | On                      |          PBX operation           |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                         DTR SIGNAL                         |
          |------------------------------------------------------------|
          | Setting                    |             SW1/4             |
          |----------------------------+-------------------------------|
          | » Off                      |          DTR normal           |
          |----------------------------+-------------------------------|
          | On                         |        DTR forced high        |
          +------------------------------------------------------------+