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 |
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 |