CHAPTER 2
                       MODEM SETUP


In order for two computers to communicate via the 
telephone system, it is necessary that each be equipped 
with a device called a MODEM (MOdulator/DEModulator).

The modem accepts digital signals from the transmitting 
computer, converts these tones in the audio range that are 
coded to represent the original digital data.

At the receive end, the tones are converted back to the 
original digital form and passed on to the receiving 
computer.  Each modem actually contains both a send and 
receive channel so there can be a continuous and 
simultaneous passing of information in both directions 
between the two computers.

For the communication process to work, it is ESSENTIAL 
that both modems be compatible, and that they use 
identical conventions for signaling tones, data 
representation and data transmission rates (baud rate).

Fortunately, industry standards have established most of 
the details required for compatibility, and users are left 
to decide only a few main functions.

Two main categories of modem exist:

1)  asynchronous modems, designed to move one
    character at a time, and
2)  synchronous modems, designed to move a block of
    characters in a continuous high speed burst.

For purposes of connecting to the OSFN, our modems are 
standard ASYNCHRONOUS modems that will operate at speeds 
of up to 14.4 baud rates.  Your modem should be compatible 
(the manual may quote standards such as CCITT V.22bis, or 
Hayes compatible).

If you have a choice, SELECT the highest speed your modem 
is capable of, since it will move data between the 
computers more quickly.  It will also be necessary to set 
the data format.

NOTE:  PLEASE USE 8 DATA BITS, NO PARITY, AND ONE
       STOP BIT FOR EAST BAY, PROVIDENCE, AND
       NORTHERN RI.  FOR THE SOUTH COUNTY (URI)
       NUMBER USE 7 DATA BITS, EVEN PARITY AND 1 STOP
       BIT.

Data rate and data format can usually be set by switches 
on the modem, or through software commands.  Please 
consult the manuals for your equipment for guidance on how 
to do this.

It must be noted that there are many varieties of modems 
on the market, some of which can switch to much higher 
speeds, and may support sophisticated features such as 
automatic error correction. These features are NOT 
supported by OSFN.

It is the responsibility of the user to read the manuals 
provided with your equipment, and to ensure that such 
features are turned off.  The communication software 
driving your modem generally provides the means of 
controlling these features.

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