300 BPS DCM-1 Modem  (260-1172)    Installation        Faxback Doc. # 5974

Figure 1 shows the connection of a Modem I to telephone lines using the new
modular connectors.  If your telephone has this type of connection, attach
your Modem I as shown.

If your telephone has the older style four-prong connection, you will need
an adapter (279-360), which allows the Modem I to be used in parallel with
your telephone.

If your telephone is wired directly to the wall, you must contact the phone
company and have them install modular connections.  Be aware however, that
you will be charged for this service.

After connecting the telephone, make sure that the MODE switch on the Modem
is OFF.  Your telephone should be operating normally now.

AC CONNECTION

Connect the AC adapter to the AC jack on the Modem's rear panel an to an
electrical wall outlet.

NOTE: Use only the supplied, UL-listed adapter. The use of any other
adapter could damage the Modem.

MODEM/COMPUTER CONNECTION VIA RS-232C INTERFACE

For most applications, you will use an RS-232C equipped computer.  Table 1
summarizes the cable and connection requirements for RS-232C equipped
TRS-80's.  Using the table, select the appropriate connector for your
computer.  Connect the computer's RS-232C interface to the specified
connection point on the Modem.

┌───────────────────┬───────────┬─────────────────────────────────────────┐
│TRS-80 MODEL       │  CABLE    │            CONNECTION POINT             │
│                   │           ├─────────────────────┬───────────────────┤
│                   │           │ TRS-80              │ MODEM I           │
├───────────────────┼───────────┼─────────────────────┼───────────────────┤
│Model I, Level II  │  26-1145* │ Card Edge on Exp.   │ DB-25 "RS-232C"   │
│                   │           │ Interface           │                   │
├───────────────────┼───────────┼─────────────────────┼───────────────────┤
│Model II           │  26-4403  │ DB-25 "CHANNEL A/B" │ DB-25 "RS-232C"   │
├───────────────────┼───────────┼─────────────────────┼───────────────────┤
│Model III          │  26-1408  │ DB-25 Serial I/O    │ DB-25 "RS-232C"   │
├───────────────────┼───────────┼─────────────────────┼───────────────────┤
│Color Computer     │  26-3020  │ DIN Serial I/O      │ DIN "RS-232C/CASS"│
└───────────────────┴───────────┴─────────────────────┴───────────────────┘

 * This is the RS-232C interface board. The cable is included.

MODEM/COMPUTER CONNECTION VIA CASSETTE INTERFACE

NOTE: When using the Cassette Comm software, communications will not be in
a true full duplex mode.  For further details, see the Cassette Comm
instruction manual.

If you have a Model I Level II computer which is not equipped with an
RS-232C interface board, you may use the cassette interface of your
computer for serial "Cassette-Comm" software and the appropriate cable
(26-1139/3009, respectively).

Connect the cable to the TAPE connector on your computer and to the
RS-232C/CASS connector on the Modem.

NOTE: The Model III cassette circuitry can not be used for serial
communications with the Modem.

(css/BKL-01/25/96)