Toshiba Portege 3500 User Manual page 209

S-registers
I-2
This register determines the number of rings the modem will
count before automatically answering a call. Enter 0 (zero) if you
do not want the modem to automatically answer at all. When
disabled, the modem can only answer with an ATA command.
Range: 0-255
Default: 0
Units: rings
This register is read only. The value of S1 is incremented with
each ring. If no ring occurs over a six-second interval, this
register is cleared.
Range: 0-255
Default: 0
Units: rings
This register determines the ASCII values used for an escape
sequence. The default is the + character. The escape sequence
allows the modem to exit data mode and enter command mode
when on-line. Values greater than 127 disable the escape
sequence.
Range: 0-255, ASCII decimal
Default: 43
Units: ASCII
This register determines the ASCII values as the carriage return
character. This character is used to end command lines and
result codes.
Range: 0-127, ASCII decimal
Default: 13 (carriage return)
Units: ASCII
Portégé 3500