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                       Hayes 2400-SmartModem Command Set
                       =================================

Cmd     Settings     Meaning
---     --------     -------

ATB     ATB0         CCIT format *
           1         BELL format

ATE     ATE0         Commands not echoed
           1         Commands echoed *

ATL     ATL0         Speaker volume low
           1         Low
           2         Medium *
           3         High

ATM     ATM0         Speaker always off
           1         Speaker on except while connected *
           2         Speaker always on
           3         Speaker on except while connected & dialing

ATQ     ATQ0         *
           1         Quiet mode

ATV     ATV0         Numeric response codes
           1         Verbose response codes *

ATX     ATX0         SM-300 compatibility mode
           1         Extended 'connect' msgs
           2         Dialtone detect
           3         Busy detect
           4         Dialtone and busy detect *

AT&J   AT&J0         RJ-11/41/45 jack *
           1         RJ-12/13 (A A1 control leads)

AT&L   AT&L0         Dialup async/sync *
           1         Leased line async/sync

AT&M   AT&M0         Async *
           1         Sync mode 1 (async call placement)
           2         Sync mode 2 (stored number dial DTR)
           3         Sync mode 3 (manual dial DTR control)

AT&G   AT&G0         No guard tones *
           1         550 Hz guard tone
           2         1800 Hz guard tone

AT&P   AT&P0         US 39%make 61%break pulse dial *
           1         UK 33%make 67%break
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Cmd     Settings     Meaning
---     --------     -------

ATY     ATY0         No long space disconnect *
           1         Long space disconnect, recv & xmt

AT&C   AT&C0         Carrier detect always on *
           1         Carrier detect follows signal

AT&D   AT&D0         Ignore DTR *
           1         DTR low = command mode (stays online)
           2         DTR low = drop connection
           3         DTR low = ATZ

AT&R   AT&R0         Clear-to-send tracks RTS *
           1         CTS for half-duplex transmit

AT&X   AT&X0         Transmit clock internal *
           1         Clock from DTE pin 15
           2         Clock from rcv signal out pin 15

ATA                  Enter answer mode

A/                   Execute last command

ATD        T         Tone dial
           P         Pulse dial
           R         Reverse mode (ans/orig)
           W         Wait for dialtone
           @         Wait for quiet answer
           ,         Pause
           !         Flash
           ;         Return to command state
           S         Dial stored number

ATH     ATH0         Hang up (on-hook)
           1         Pickup line (off-hook)

ATO     ATO0         Return online
           1         Retrain equalizer & return online

ATZ                  Reset configuration from stored profile

AT&F                 Reset configuration from factory settings

AT&W                 Store active profile

AT&Znn               Store one dial number

ATI     ATI0         Show product code
           1         Show checksum
           2         Verify checksum
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Cmd     Settings     Meaning
---     --------     -------

AT&T   AT&T0         Terminate any test
           1         Local analog loopback
           3         Local digital loopback
           4         Allow a remote digital loopback request
           5         Prohibit remote digital loopback request
           6         Initiate remote digital loopback
           7         Initiate remote digital loopback with selftest
           8         Initiate local analog loopback with selftest

Register   0         0-255   rings    00     Ring to answer on
           1         0-255   rings           Ring count
           2         0-127   ascii    43     Escape code char
           3         0-127   ascii    13     Carriage return char
           4         0-127   ascii    10     Line feed
           5         0-127   ascii    08     Backspace char
           6         0-255   seconds  02     Wait for dialtone
           7         1-30    seconds  30     Wait for carrier
           8         0-255   seconds  02     Pause time comma
           9         1-255   .1 sec   06     Carr detect response
          10         1-255   .1 sec   14     Lost carrier hangup
          11
          12         0-255   .02 sec  50     Escape guard time
          13
          14                 none            Options register
          15
          16                 none     00     Modem test options
          17
          18         0-255   seconds  00     Test timer
          19
          20
          21                 none            Options register
          22                 none     76'x   Options register
          23                 none     07     Options register
          24
          25         0-255   seconds  05     Sync delay to DTR
          26         0-255   seconds  00     RTS/CTS delay HD
          27                 none     00     Options register
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Result     0         OK               Acknowledge execution
Codes      1         CONNECT          0-300 bps connection
           2         RING             Ring detected
           3         NO CARRIER       No connect or lost
           4         ERROR            Error
           5         CONNECT 1200     1200 bps connection
           6         NO DIALTONE      No dialtone found
           7         BUSY             Busy signal
           8         NO ANSWER        @, no quiet answer
           9         CONNECT 0600     600 bps connection
          10         CONNECT 2400     2400 bps connection
