3 Com U.S. Robotics 3Com User’s Manual & Reference page 15

S Registers
S0 * Number of rings to answer on (0)
S1 Counts number of rings (0)
S2 * Defines escape code character (43)
S3 * Defines carriage return character (13)
S4 * Defines line feed character (10)
S5 * Defines backspace character (8)
S6 * Sets number of seconds modem waits before dialing (2)
S7 * Sets number of seconds modem waits for a carrier (60)
S8 * Comma delay time in seconds (2)
S9 * Carrier recognition time in tenths of a second (6)
S10 * Carrier Loss time in tenths of a second (7)
S11 * Touch tone spacing (mSec) (70)
S12 * Escape code time (1/50sec) (50)
S13 * Bit mapped (0)
1 Reset on DTR drop
2 Reset non-MNP buffer to 128 bytes
4 Set backspace key to delete
8 Do DS0 on DTR
16 Do DS0 on reset
32 Disable V.32bis ASL mode
64 Disable Quick Retrains
128 Disconnect on escape code
S15 * Bit mapped (0)
1 Disable ARQ/MNP for V.22
2 Disable ARQ/MNP for V.22bis
4 Disable ARQ/MNP for V.32 and V.32bis
8 Disable MNP Handshake
16 Disable MNP level 4
32 Disable MNP level 3
64 Special MNP incompatibility
128 Disable V.42
136 Disable Initial V.42 phase detection
S16 Bit mapped (0)
2 Touch tone test
4 Use internal test pattern
S18 Test Timer (sec) (0)
S19 * Inactivity time-out (min) (0)
S21 * Break length (1/100sec) (10)
S22 * ASCII Code for XON character (17)
S23 * ASCII Code for XOFF character (19)
S25 * DTR minimum pulse width (1/100sec) (20)
S27 * Bit mapped (0)
1 V21 mode
2 Enable non trellis code V.32bis
4 Disable V.32
8 Disable 2100
16 Enable V.23
32 Disable V.32bis
128 Software Compatibility Mode
S28 * Multimode training program (8)
0 Eliminates the V.32 answer tones for faster connection
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