300 BPS Internal Modem  (250-1003)    Features         Faxback Doc. # 4484

OVERVIEW
This modem has no switches or lights and is entirely controlled by the 
Tandy 1000 Computer keyboard entries. A card edge connector at one end of 
the card connects the modem to the computer's power circuitry. The other 
end of the card has two telephone connectors which let you attach a tele-
phone in parallel with existing telephone circuitry. These ASCII commands 
are supplied through the on-board UART. The UART converts parallel commands
to serial data for the modem. The microprocessor converts the serial data 
into parallel data and controls the modem using the input/output ports.

The modem circuitry is divided into six major subsections:
1. Modem Filter
2. Carrier Detect Section
3. UART
4. Microprocessor Section
5. Tone Dialer Section
6. Telephone Interface Section

Commands are used to program the Modem Board via the keyboard. You can pro-
gram the modem for Manual/Originate or Manual/Answer modes which means that 
if you are contacting a remote computer in Manual/Originate mode, you will 
manually dial the telephone number, and when you are in Manual/Answer mode, 
you will manually answer an incoming call. You can program the modem for 
Auto/Originate or Auto/Answer which means that when in Auto/Originate mode, 
the modem will automatically dial the telephone number of a remote computer,
and when in Auto/Answer mode, the modem will automatically answer an in-
coming call. 

NOTE: Before connecting the Tandy 1000 Modem Board to a phone line, notify 
your local telephone company of the following:

MANUFACTURER:                    Radio Shack
MODEL:                           Tandy 1000
USOC NUMBER:                     RJ11C
FCC REGISTRATION NUMBER:         AAO 88U-68616-DM-E
RINGER EQUIVALENCE NUMBER (REN): 0.7B

(abo-07/28/93)