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VARMODEM 1200

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