Apple Express Fax/Modem - Manual (Page 133)

H n Hook (hang up)
When the modem is on-line, you must first enter the +++ escape
sequence to take the modem back to command state before issuing the
hang up command ATH.
0 Forces the modem on-hook. Hangs up the modem’s connection to
the telephone line.
1 Forces the modem off-hook.
I n Information
0 Asks the modem for its product ID code.
1 Returns a modem code.
2 Returns OK.
3 Returns the modem’s country code.
4 Returns a list of modem features.
9 Returns Apple product code and firmware version of the modem.
L n Speaker volume This command has no effect, as the speaker is a
component of the Macintosh and set in the Sound control panel. The
command is included for compatibility purposes.
M n Speaker on/off/auto
0 Disables speaker.
1 Turns on the speaker until carrier is established.
2 Leaves the speaker on throughout the entire connection.
3 Turns the speaker on until a carrier is detected, except during
dialing.
N n Communication protocol preference Sets the modem protocol.
0 Use S37 for speed selection. If S37=0, connect at highest
possible speed. Otherwise, connect at speed specified in S37.
1 Connect at highest possible speed according to value of S37.
Fallback if necessary.
2 Same as N1 for compatibility reasons.
Note: For N1 or S37=0, the setting of ATB is ignored. The modem
automatically determines Bell or CCITT mode.
121 M O D E M C O M M A N D S E T