Card Type	Modem (asynchronous)
Chip Set	Unidentified
Maximum Data Rate	2400bps
Data Bus	8-bit ISA
Data Modulation Protocol	Bell 103/212A ITU-T V.22

SERIAL PORT ADDRESS
Setting	IRQ	SW1/A	SW1/B
COM1 (3F8h)	4	On	On
COM2 (2F8h)	3	Off	Off
COM3 (3E8h)	4	On	Off
COM4 (2E8h)	3	Off	On

MISCELLANEOUS TECHNICAL NOTES

Diagram not available

BIT-MAPPED REGISTER S14
Format:		AT [cmds] S14=n [cmds]
Default:		170
Range:		0-174
Unit:		Bit-mapped
Description:		Controls echo, result codes and display, dial mode, and answer/originate mode.
Bit	Value	Function
0	í 0	Not used
1	0 í 1	Command echo disabled Command echo enabled
2	í 0 1	Result codes enabled Result codes disabled
3	0 í 1	Display result codes in numeric format Display result codes in verbose format
4	í 0	Not used
5	0 í 1	Tone dial enabled Pulse dial enabled
6	í 0	Not used
7	0 í 1	Answer mode enabled Originate mode enabled

BIT-MAPPED REGISTER S21
Format		AT [cmds] S21=n [cmds]
Default:		0
Range:		0-185
Unit:		Bit-mapped
Description:		Selects jack type, CTS/DCD/DSR signals, low DTR action, and the long space disconnect function
Bit	Value	Function
0	í 0 1	Selects RJ-11, RJ-41S, or RJ45S jack Selects RJ-12 or RJ-13 jack
2, 1	í 00	Not used
4, 3	í 00 01 10 11	DTR signal ignored Modem goes to command mode on low DTR Modem disconnects on low DTR; Auto-Answer is disabled Modem is initialized on low DTR
5	í 0 1	DCD forced high DCD normal
6	í 0	Not used
7	í 0 1	Long space disconnect function disabled Long space disconnect function enabled

BIT-MAPPED REGISTER S22
Format		AT [cmds] S22=n [cmds]
Default:		118
Range:		0-255
Unit:		Bit-mapped
Description:		Controls speaker volume and controls, limits results codes, and pulse dial make/break ratio.
Bit	Value	Function
1, 0	00 01 í 10 11	Volume off Low level volume Medium level volume High level volume
3, 2	00 í 01 10 11	Speaker off Speaker off on carrier Speaker always on Speaker on during handshake
6 - 4	000 100 101 110 í 111	Basic result codes only enabled Basic and connection speed result codes enabled Basic and connection speed result codes and dialtone detection enabled All result codes except dialtone detection enabled All result codes enabled
7	í 0 1	39/61ms at 10pps (North America) 33/67ms at 10pps (Europe)

BIT-MAPPED REGISTER S23
Format		AT [cmds] S23=n [cmds]
Default:		7
Range:		0-247
Unit:		Bit-mapped
Description:		Grants/denies remote digital loopback, controls DTE rate and parity, and sets guard tone
Bit	Value	Function
0	0 í 1	Remote digital loopback denied Remote digital loopback allowed
2, 1	00 01 10 í 11	Sets serial port speed to 0-300bps Sets serial port speed to 600bps Sets serial port speed to 1200bps Sets serial port speed to 2400bps
3	í 0	Not used
5, 4	í 00 01 10 11	Parity even Space parity Parity odd Mark or no parity
7, 6	í 00 01 10 11	Guard tone disabled Guard tone 550Hz enabled Guard tone 1800Hz enabled Not used

BIT-MAPPED REGISTER S27
Format			AT [cmds] S27=n [cmds]
Default:			64
Range:			0-64
Unit:			Bit-mapped
Description:			Selects ITU-T/Bell modes
Bit	Value	Function
5 - 0	í 000000	Not used
6	0 í 1	ITU/T mode Bell mode

DIAL
Type:	Immediate
Format:	AT [cmds] D<#> [cmds]
Description:	Dials telephone number according to any modifiers included in the string
Note:	Any combination of modifiers can be used to produce the desired dial functions in sequence.
Modifier	Function
L	Re-dial last number
P	Pulse dialing enabled
R	Answer mode enabled, originate mode disabled following handshake initiation
S=n	Dial stored telephone number n
T	Tone dialing enabled
W	Dialing resumed following dial tone detection
,	Dialing paused for amount of time specified in S8 register
!	Modem commanded to go off-hook for specified time before returning on-hook
@	Wait for quiet answer
;	Modem returned to command state after dialing

REPORT INFORMATION
Type:	Immediate
Format:	AT [cmds] In [cmds]
Description:	Displays information requested
Command	Function
I0	Reports product code, e.i. 24x, the x represents the revision level
I1	Reports ROM checksum
I2	Reports ‘OK’
I3	Reports product number