US Robotics 56K Series Manual page 86

Register Default
S11 70
S12 50
S13 0
80
Function
Dropping DTR hangs up the modem
Sets the duration and spacing, in milliseconds, for tone dialling
Sets the duration, in fiftieths of a second, of the guard time for the escape
code sequence (+++)
Bit-mapped register
Select the bit(s) you want on and set S13 to the total of the values in the
Value column
For example: ATS13 = 17 enables bit 0 (value is 1) and bit 4 (value is 16)
Bit Value Result
0 1 Reset when DTR drops
1 2 Reset non-MNP transmit buffer from 1.5K to 128
bytes*
2 4 Set backspace key to delete
3 8 On DTR signal, auto dial the number stored in
NVRAM at position 0