Intel LAN+Modem56 PC Card PRO/100 - Manual (Page 133)

Modem Reference 6-9
Fn Online Data Character Echo command
Ths ATFn command determines whether the modem will echo data from
the DTE. This modem does not support the F0 version of the command.
To ensure backward compatibility, the modem will accept F1.
F0 Online data character echo enabled (not supported;
returns ERROR)
F1 Online data character echo disabled
Hn Switch Hook Options
The ATHn command hangs up the modem or prepares it for dialing.
ATH0 Causes the modem to go on-hook (default).
ATH1 Causes the modem to go off-hook (this command is
restricted in some countries).
In Request ID Information
The ATI command has various options which are used to instruct the
modem to provide specific information about itself.
I0 Displays modem controller firmware revision (same as
I3)
I1 Calculates ROM checksum and displays it on the DTE
(for example, 12AB)
I2 Performs a ROM check and calculates and verifies the
checksum. displaying OK or ERROR.
I3 Displays modem firmware revision information
I12 Returns country code (for example, North America)