4. Click Internal Modem. Then click Next.
Write down the displayed settings here: COM Port_________ IRQ_________ You will need to know these settings later. Click Next. If you do not have a free setting, you will see a screen like the follwoing. Click Finish to exit ComTest. Go to What to Do with ComTests Recommendation on page 10.
5. If you have a free setting, you will see a screen like this.
(COM2/IRQ3 is free in this example.) 8
6. When you see this screen, click Finish to exit ComTest.
Testing an Installed Modem
If there is a modem already installed in your computer, you can determine its COM and IRQ settings by selecting the Test an installed modem option. Follow the instructions on screen until you see the screen that tells you Testing is complete. This screen will also tell you which COM and IRQ settings your present modem is using. These are the settings you want to use for your new U.S. Robotics modem. Write down the displayed settings here: COM Port_________ IRQ_________ Turn off and unplug your computer and remove your present modem using its documentation as a guide. Go to How to Change the Modems Settings on page 12.
If ComTest recommended COM 1/IRQ 4 or COM 2/IRQ 3, turn to How to Change the Modems Settings on page 12. Otherwise, go to What to Do with ComTests Recommendation on page 10.
What to Do with ComTests Recommendation
NOTE: If your communications software requires a modem setting that ComTest does not recommend, there is a good chance that the setting is being used by another device in your system. To free that setting in your system, consult your computers manual. Go to How to Change the Modems Settings on page 12.
If ComTest recommended COM3/IRQ4 or COM4/IRQ3 Do not use either of these settings. While the COM port part of the setting is acceptable (ComTest only recommends COM ports that are not being used), the IRQ part of the setting 10
is not acceptable. When ComTest recommends either COM3/IRQ4 or COM4/IRQ3, the IRQ in the setting is being used by another accessory. You could use the suggested IRQ for the modem, but you run the risk that the modem and/or the other accessory sharing the IRQ might not work properly. If you do not have a sound card, use COM3/IRQ5. Write COM3 and IRQ5 where it will be convenient during the software installation. You will have to change the settings on your modem. Go to How to Change the Modems Settings on page 12. If you do have a sound card, use COM2/IRQ3. To use this setting, you have to first disable your computers second serial port (COM2). This is a pronged socket on the back of your computer. Go to your computer manufacturers manual.

6. Once the modem is in the slot, fasten it firmly into place using the screw that you removed in step 4. 7. Replace the computers cover and fasten it with the screws you removed in step 3. 8. If you currently have a phone plugged into the wall jack you plan to use for the modem, disconnect the phones cord from the jack.
WARNING : The phone jack you
use must be for an ANALOG phone line (the type found in most homes). Many office buildings have digital phone lines. Be sure you know which type of line you have. The modem will be damaged if you use a digital phone line. 9. Plug one end of the phone cord that came with the modem into the TELCO jack at the rear of the modem. Plug the other end of the cord into the wall jack. 10.If you wish to use a phone through the line the modem uses (when the modem is not in use), plug your phones cord into the modems PHONE jack.
NOTE: You cannot use the modem
and a phone at the same time if they share the same telephone line. 11. Plug the microphone into the MIC jack on the modem. 12. To use the modems full-duplex speakerphone capabilities, plug a set of powered external speakers (not included) into the SPEAKER jack on the modem. 17
13.Plug the power cords, cables, and peripherals back into the computer and turn the computer on. 14.Start Windows. 15.If you have your modem set to COM1/IRQ4 or COM2/IRQ3, go to Software Installation on page 47. If you have your modem configured to any other setting, open Program Manager and double-click the Main icon.
16.Double-click the Control Panel icon.
17. Double-click the Ports icon.
18.If its not already selected, click the COM port for your modem. Then click Settings.
20.In the Interrupt Request Line (IRQ) box, select the IRQ that ComTest recommended.
21.Click OK. 19.Click Advanced.
22.You will see a screen prompting you to restart Windows. Click Restart Now.
When Windows restarts, you are ready to install the Connections program group and
register your modem online. Turn to Software Installation (page 47) for more information.
INTERNAL MODEM INSTALLATION WITH WINDOWS 95
NOTE: Complete the instructions in the section Before You Begin (Windows 95 Users) on page 3 before continuing with the following instructions.

Your new U.S. Robotics modem is a Plug and Play device. This means Windows 95 should be able to detect your modem automatically after you plug it into your computer. The next section covers preparing your new modem for Plug and Play installation.
How to Prepare for Plug and Play Installation
1. Touch an unpainted metal part of your computer (the back is usually unpainted) to discharge static electricity. Static can damage your modem. 2. Take the modem out of its plastic bag. 3. Find the jumper shunts (small black plastic pieces) on the COM port and IRQ jumper pins on your modem. They should be in roughly the area indicated in the following illustration. When doing a Plug and Play installation, the jumper shunts should be placed so that they are hanging from single jumper pins rather than on pairs of pins. Move your jumper shunts so they are hanging as in the following diagram.
NOTE: Before installing your
modem, write its serial number here:
SERIAL NUMBER________________
Youll find the serial number underneath the bar code on the white sticker on the modem and on the outside of the box the modem came in. If you call our customer support department, a customer support representative will ask you for the serial number. This will help him or her identify your modem.
NOTE: If you need to move the
jumper shunts, grasp them with a tweezers or a needle-nosed pliers. DO NOT grasp too firmly, however, or you may crush the jumper shunts. If a jumper shunt seems stuck, try gently rocking it back and forth as you lift.
in the following diagrams. Your computer may differ in appearance from these diagrams, but the basic principle for removing the cover should be the same. Refer to your computer manufacturers manual if you need further instructions.
TIP: Before you unplug any cords,
label them or make a sketch of how they are connected. This can be helpful when you plug them back in later.
CAUTION : To avoid risk of
electric shock, make sure your computer and all peripheral devices are turned off and unplugged from electrical outlets. 3. Remove the screws from your computers cover and then remove the cover, as shown 24

4. Find an empty ISA expansion slot thats at least as long as the gold edge of your modem. (ISA slots are usually black plastic grooves lined with silver metal.) Unscrew and remove the expansion slot cover (the long narrow piece of metal that keeps dust from entering through the opening perpendicular to the slot). Be careful not to drop the screw into the computer. You will need it later to screw the modem into place.
5. Holding the modem at each corner, with the gold edge facing the slot, push the modem down as gently as possible until it snaps into the expansion slot. (The following diagram shows horizontally aligned expansion slots. Some computers have vertically aligned slots. The instructions apply to both styles.) You need to apply a little pressure to seat the modem properly. Sometimes a gentle back-and-forth motion helps fit the modem all the way into the slot. If you feel resistance, the modem may not be properly lined up with the slot. Do not force it into the slot. Remove the modem and try again.
this jack, disconnect the telephone cord from the jack.
use must be for an ANALOG phone line (the type found in most homes). Many office buildings have digital phone lines. Be sure you know which type of line you have. The modem will be damaged if you use a digital phone line. 6. Once the modem is in the slot, fasten it firmly into place using the screw that you removed in step 4. 7. Replace the computers cover and fasten it with the screws you removed in step 3. 8. Locate the wall jack you plan to use for the modem. If you have a phone plugged into 26 9. Plug one end of the phone cord included with the modem into the TELCO jack at the rear of the modem. Plug the other end of the cable into the wall jack. 10. If you wish to use a phone on the line the modem is using when the modem is not in use, plug your phones cord into the modems PHONE jack.
and a phone at the same time if they share the same telephone line. 11. Plug the microphone into the MIC jack on the modem. 12. To use the modems full-duplex speakerphone capabilities, plug a set of powered external speakers (not included) into the SPEAKER jack on the modem.
13.Plug the power cords, cables, and peripherals back into the computer and turn on the computer.
Installing the Modem Drivers
NOTE: If you wrote 950b on page 4 of this Users Guide, go to Installing Modem Drivers with Windows 95 Version 950b on page 31. Otherwise, follow these instructions.
Installing Modem Drivers with Windows 95 Versions 950 and 950a 1. When Windows 95 restarts, it should detect the modem. If it does, you will see the following screen.
2. When you see this screen, insert the Connections CD into your CD-ROM drive and type D:\ to replace the A:\. (If your CD-ROM drive has a different letter name, type that letter instead of D.)
Click Driver from disk provided by hardware manufacturer. Then click OK. Click OK. Windows will load the modems drivers.

*All U.S. Robotics internal modems have a 16550 UART.
NOTE: DO NOT select a 28,800,
14,400, or 12,000 bps serial port rate, if offered. Your modem will NOT work correctly with any of these settings. Fix or lock the serial port (baud) rate (if its referred to as autobaud, select OFF). 51

USING MODEM STATION

What Does Modem Station Do?
Modem Station provides a simple to use interface that makes communicating with your modem easy. Modem Station allows you to point and click your way through configuration. Modem Station can automatically detect your modem and provide you with all the technical information you need, whenever you need it! You may want to tweak your modem for optimum performance.

Installing Modem Station

If you did not install Modem Station when you first installed the Connections CD, please follow these instructions. 1. Insert the Connections CD into your CDROM drive. 2. Double-click the My Computer icon on your desktop. 3. Double-click the CD-ROM icon. 4. Double-click the usrtools folder. 5. Double-click the umssetup icon.

Why Modem Station?

Modem commands can be confusing and difficult to memorize. Communications software often requires technical information about your modem.
6. You will be asked whether you wish to install Modem Station. Click Yes. 7. Wait a few moments for the Installation Wizard to load. 8. After reading the information on the Welcome screen, click Next.
9. When you see this screen, click Next to accept the default directory or click Browse to change directories.
10.Click Next on the following screen to accept the default program folder. You can place Modem Station in an existing folder by selecting one from the list.
11. When you see the following screen, click Finish to complete the installation.
If this is the first time youve installed Modem Station, you may be asked to restart your computer.

Starting Modem Station

1. If you did not start Modem Station from the Setup program, please start it now. 2. Click Windows Start button and then point to Programs. Click U.S. Robotics Modem Station (or the folder you selected during installation). 3. Click the Modem Station icon. This brings up the main menu.
The main menu gives you direct access to the following options: DETECT NEW MODEMS This option detects U.S. Robotics modems installed on your system and shows what COM port they are using. Click this option if you are running Modem Station for the first time, if you are changing modems, or if you simply need to know what port your modem is using. TERMINAL Terminal allows you to send commands directly to your modem and displays the responses. You can use Terminal to dial up BBSs. In addition, you can configure your modem using Terminal. However, it is much easier to use the Modem Configurator. 55

For detailed information about these settings, refer to the Glossary or the Technical Quick Reference sections of this manual.
Once you have configured your Connection Control settings, click Save to Modem to save your settings.

TIP: On external modems,

receiving a Data Terminal Ready signal from the PC causes the TR light to light up. Click Help for quick definitions of terminology used in this screen.

Using Modem to Computer

These settings control how your modem and computer communicate with each other. They control what you see on your terminal screen and how results are displayed.
If you look in the upper left hand corner of the display, you will see the commands currently in use. The Modem to Computer screen allows you to configure the following settings: LOCAL ECHO RESULT CODES RESULT CODE PREFERENCES
TIP: If you type ATDT and see
AATTDDTT on your screen, it is possible that both your software and modem have Local Echo set to ON. Turn Local Echo OFF on EITHER the modem or the software to solve this problem. For details on using the commands in this screen, refer to the Glossary or Technical Quick Reference sections of this manual. Click Help to see quick definitions of terminology used in this screen. This screen also includes a chart of the ways result codes can be displayed. Click Codes to view a chart of the display options. Once you configure your settings, click Save to Modem to save your choices.
CONNECTION RATES The Connection Rates screen allows you to configure modem speeds and protocols.
This screen allows you to configure the following settings: MODULATIONS V.34 SYMBOL RATES SPEEDS Again, once you have selected your settings, click Save to Modem to save them. When you are finished, click Exit to return to the Modem Configurator menu. Please refer to the main body of the manual and the Glossary for detailed information about the terminology and settings used in this screen. Click Help for quick definitions of terminology used in this screen.

WARNING! Use caution

when changing connection settings. Improper settings may cause your modem to function incorrectly, disconnect, or fail to connect at all.
In the upper left hand corner of the screen you will see the current connection commands. 65
DIALING/ANSWERING The next screen allows you to adjust how your modem initiates and receives calls.
STORED NUMBERS The Stored Numbers screen displays the phone numbers currently stored in your modems memory. Use this screen to edit or add numbers stored in the modems memory.
Using this screen, you can configure the following dial settings: 66 WAIT FOR CARRIER AUTO-ANSWER # OF RINGS SPEAKER OPERATION DIALING METHOD SPEAKER VOLUME To store a number in your modems memory, simply click in one of the entry boxes. Type in the phone number exactly as you would dial it. Position Zero has a special feature. You can set your modem to automatically dial this

number when your computer is turned on or when it is reset. This is very useful if you are using your modem with a dumb terminal or know that you need to connect to a specific bulletin board or listing service. You can change stored numbers by highlighting them and then typing the new numbers in their place. Once you store your numbers, you can dial them by entering a single command from Terminal Mode: (for example: ATDS0, ATDS1, or ATDS2). Your U.S. Robotics modem comes with one phone number already stored in Position 0. If you havent changed the default, typing ATDS0 will automatically dial the 3Com BBS. Once you enter the numbers you wish to store, click Save to Modem to store them. Click Exit to return to the Main menu.
The last option, Restore Defaults, resets your modem to factory specifications. This option is available from many of the screens within Modem Station.
TIP: Restore Defaults will set
your modem back to factory specifications. It is a good place to start when troubleshooting.
Using the Extended Information Screens
The Extended Information screens provide important and useful information about your modem. We devote a separate section to the Extended Information screens so that we can explain
what youll see (and why it is important to you) as fully as possible. There are a series of commands used to obtain detailed information from U.S. Robotics modems. Extended Information provides a convenient way to get that important information without memorizing the commands. From the Detect New Modems screen, click Extended Information. The Extended Information screen provides access to the following information about your modem: 68 ROM CHECKSUM PRODUCT ACTIVE PROFILE STORED PROFILE CONFIGURATION PROFILE LINK DIAGNOSTICS VxD CONFIGURATION
DIAL/SECURITY Winmodem users will have access to VxD information via these screens. Courier users will have access to Dial/Security information. Click ROM Checksum to bring up the following screen.
Technicians use the ROM Checksum to verify information stored in the modems Read Only Memory. For information about the specific
modem you are using, click Product to bring up the next screen.
To see information about the profile in use, click Active Profile to bring up the next screen.
The Product screen displays the make and model of your modem. Your modem is able to store two configurations or profiles. Only one can be active at any time.

If you are using an external modem, the COM port may not be enabled.
TROUBLESHOOTING AND ONLINE H ELP RESOURCES PROBLEM
The modem displays double characters on your monitor. The modem wont go off hook to dial or doesnt answer the phone.
Both the modems and softwares local character echoes are turned on. You may have plugged your modems phone cord into a digital line. You might have a bad phone cord connection to your modem.
Disable Local Echo in your software OR on your modem (not both). Turn local echo off on the modem by typing ATE0 and pressing ENTER in your softwares terminal mode. To turn the local echo off in the software, refer to its documentation. Plugging your modems phone cord into a digital phone line can damage the modem. Call your phone company if you are unsure whether or not your phone line is digital. The phone cord should be plugged into the TELCO jack on the modem and an analog wall phone jack. The phone cord should not exceed 12 feet in length. Use the phone cord included with your modem if possible. Have your phone company make sure that the phone jack is wired properly (tip and ring are on the inside pair of wires). There should be no line splitters, fax machines, or other devices between the modem and the wall jack. Place the call again. Calls are routed differently each time. To verify a valid phone connection, enter the RapidComm Voice softwares Terminal mode, type ATX3DT18479825092 (the 3Com BBS), and press ENTER. This string bypasses the dial tone, allowing a connection if the modem is working properly. Answer your voice mail to restore your normal dial tone. Your dial tone may be altered when messages are waiting.
You may have devices between the modem and the phone jack. You may have a poor line connection. If you have voice mail, you may have messages waiting.
The modem wont go off hook to dial or doesnt answer the phone.
Your software may not have auto answer enabled.
Enable the auto answer feature. In the RapidComm Voice softwares Terminal mode, type ATS0=1 and press ENTER. NOTE: You need to enable auto answer before every session unless you alter your softwares initialization string to permanently enable auto answer. Try placing the call again. The phone company routes calls differently each time. To verify a valid phone connection, enter the RapidComm Voice softwares Terminal mode and type ATX3DT18479825092 and press ENTER (the phone number is the 3Com BBS). This string bypasses the dial tone, allowing a connection if the modem is functioning properly. Check http://www.3com.com/56k for a list of ISPs that observe the ITU 56K standard and/or offer x2 technology. (FCC rules restrict power output of the service providers modems, limiting download speeds to 53 Kbps.) Call your phone company to determine if this might be the problem. You can also run U.S. Robotics Line Test utility to determine if your phone line is 56K compatible. Visit our Line Test Web page at http://www.3com.com/56k. Remove all devices between the modem and the phone jack. Make sure the phone cord you are using is no longer than 12 feet. Use the phone cord included with your modem.

Both modems exchange carrier signals but fail to establish a link.
You may have a poor line connection. Your Internet Service Provider (ISP) may not be ITU 56K/x2 technology capable. The phone lines in your area not be compatible with 56K technology. There may be devices between your modem and the phone jack.
Your 56K modem cannot achieve a 56K Internet connection.
Your modem wont connect at 2400 bps with a 2400 bps modem.
The modem youre trying to connect with could be an older model that doesnt support error control.
You can disable error control on your modem by typing AT&M0 in terminal mode and pressing ENTER. Now try placing the call to the remote modem again. When finished, reset your modem to enable the error control features. In terminal mode, type ATZ and press ENTER. Note: ATZ4 or AT&F1 are often the best reset strings, as they restore hardware flow control defaults. Set your modems word length, parity, and stop bits the same as the remote modem or BBS you are calling. Typical settings are: data bits=8, stop bits=1, parity=none, flow control=hardware (RTS/CTS) Make sure the software and modem have the same flow control settings (hardware [RTS/CTS] and software [xon/xoff]). In terminal mode, type AT&F1 and press ENTER to load the optimal settings.
Your screen keeps displaying random garbage characters.
You could have a conflict with the remote modems settings for word length, parity, and stop bits. Your software and modem might not be set to the same flow control settings. The best flow control settings might not be enabled on your modem.
Your communications software is reporting many cyclic redundancy check (CRC) errors and low characters per second (CPS).
You may have a bad phone line. Optimum flow control settings may not be enabled on your modem. The serial port rate in your communications software may be set too high for your modems UART or your areas phone lines.
Try placing the call again. The phone company routes calls differently each time. In terminal mode, type AT&F1 and press ENTER to load the optimum hardware flow control settings. Lower the serial port rate in your communications software to 57,600 bps, 38,400 bps, or 19,200 bps. Some software programs (including AOL) allow port settings of 14,400, 28,800, and 33,600. These settings are invalid and should not be used. NOTE: The port rate for an 56K modem cannot be set lower than 57,600 if you want to achieve a high-speed connection. Try using a different file transfer protocol. Do not use Xmodem if other protocols are available. Zmodem is the preferred protocol. Disable any Terminate and Stay Resident (TSR) programs running in the background. If you have software running as a TSR, check the softwares manual for information about disabling its ability to operate as a TSR.
The remote site you are dialing into may have trouble with the file transfer protocol. There may be a Terminate and Stay Resident (TSR) program (such as a screen saver or virus scanner) running in the background, disrupting data communications.

Your communications software is reporting many cyclic redundancy check errors (cont.). Errors are constantly occurring in your V.17 fax transmissions.
You may be trying to download a file to a compressed area of your hard disk. Your modem may not have the correct initialization string for fax transmissions. There may be a Terminate and Stay Resident (TSR) program running on your system. Your baud rate may be set too high. You may be trying to fax a compressed file The RapidComm Voice softwares port settings may be incorrect. If you are using an external modem, it may not be turned on
Download to an uncompressed area on your hard drive. In your communications software, change the modem initialization string to AT&H3&I2&R2S7=90. Disable any TSR programs (such as screen savers or virus scanners) running in the background. If you have software running as a TSR, see its manual for information about disabling its ability to operate as a TSR. Lower baud rate to 9600, 7200, or 4800. Open the file in the application in which it was created. Select RapidComm as the printer and then print the file. Make sure the RapidComm Voice softwares port settings match your modem's. The power switch is located on the back of the modem by the phone jacks.
The RapidComm Voice software fails to initialize the modem.
TROUBLESHOOTING AND ONLINE H ELP RESOURCES
RapidComm Voice Software Troubleshooting Tips
PROBLEM: The lights in the RapidComm Voice softwares modem light monitor do not correspond to the actual lights on an external modem. DIAGNOSIS: Under certain circumstances, the modem light monitor does not correctly report the activity of the modem. We are aware of this problem and are working to rectify the situation in upcoming versions of the software. PROBLEM: The station ID works intermittently. DIAGNOSIS: Under certain circumstances (including receiving a fax), the station ID may not work properly. 82
PROBLEM: RapidComm Voice software does not work properly at 115.2 kbps. DIAGNOSIS: The presence of disk compression software on your system hampers the RapidComm Voice softwares ability to work properly at 115.2 kbps. Removal of the disk compression software from your system will allow RapidComm Voice software to operate properly at 115.2 kbps.
If Plug and Play Does Not Detect Your Modem
1. Click Windows 95 Start and click Shut Down. When asked if you wish to shut down your computer, click Yes. When Windows 95 indicates that it is safe to turn off your computer, turn it off and wait 15 seconds. Then turn the computer back on. Windows 95 may detect your modem upon this restart even if it did not detect the modem during the initial installation. If you see screens indicating that new hardware has been detected by Windows 95, turn to Installing the Modem Drivers (page 27 for internal modems, page 39 for external modems). If not, continue with the next step.

cyclic redundancy checking (CRC) An error-detection technique consisting of a test performed on each block or frame of data by both sending and receiving modems. The sending modem inserts the results of its tests in each data block in the form of a CRC code. The receiving modem compares its results with the received CRC code and responds with either a positive or negative acknowledgment. data communications The transmission or sharing of data between computers via an electronic medium.
data compression table A table containing values assigned for each character during a call under MNP5 data compression. Default values in the table are continually altered and built during each call: The longer the table, the more efficient throughput gained. data mode Mode used by a modem when sending and receiving data files. DCE Data Communications (or CircuitTerminating) Equipment, such as dial-up modems that establish and control the data link via the telephone network.
default Any setting assumed, at startup or reset, by the computer's software and attached devices. The computer or software will use these settings until changed by the user or other software. detect phase In the ITU-T V.42 error-control protocol, the first stage in establishing if both modems are attempting to connect have V.42 capability. dictionary The term used for compression codes built by the V.42 bis data compression algorithm.
digital loopback A test that checks the modem's RS-232 interface and the cable that connects the terminal or computer and the modem. The modem receives data (in the form of digital signals) from the computer or terminal, and immediately returns the data to the screen for verification. digital signals Discrete, uniform signals. In this manual, the term refers to the binary digits 0 and 1. DTE Data Terminal (or Terminating) Equipment. A computer that generates or is the final destination of data.
duplex Indicates a communications channel capable of carrying signals in both directions. See half duplex, full duplex. Electronic Industries Association (EIA) Group which defines electronic standards in the U.S. error control Various techniques that check the reliability of characters (parity) or blocks of data. V.42 and MNP error-control protocols use error detection (CRC) and retransmission of flawed frames (ARQ). facsimile A method for transmitting the image on a page from one point to another. Commonly referred to as fax. 93
fax mode The mode used by a modem to send and receive data in facsimile format. See definitions for V.17, V.27ter, V.29. flow control A mechanism that compensates for differences in the flow of data into and out of a modem or other device. See commands &Hn, &In, &Rn. frame A data communications term for a block of data with header and trailer information attached. The added information usually includes a frame number, block size data, error-check codes, and Start/End indicators.

full duplex Signals can flow in both directions at the same time over one line. In microcomputer communications, may refer to the suppression of the online local echo. half duplex Signals can flow in both directions, but only one way at a time. In microcomputer communications, may refer to activation of the online local echo, which causes the modem to send a copy of the transmitted data to the screen of the sending computer. Hz Hertz, a frequency measurement unit used internationally to indicate cycles per second.
ITU-T An international organization that defines standards for telegraphic and telephone equipment. For example, the Bell 212A standard for 1200-bps communication in North America is observed internationally as ITU-T V.22. For 2400-bps communication, most U.S. manufacturers observe V.22 bis. LAPM Link Access Procedure for Modems. An error-control protocol defined in ITU-T Recommendation V.42. Like the MNP protocols, LAPM uses cyclic redundancy checking (CRC) and retransmission of corrupted data (ARQ) to ensure data reliability.
local echo A modem feature that enables the modem to display keyboard commands and transmitted data on the screen. See command En. MNP Microcom Networking Protocol, an errorcontrol protocol developed by Microcom, Inc., and now in the public domain. There are several different MNP protocols, but the most commonly used one ensures error-free transmission through error detection (CRC) and retransmission of flawed frames.
modem A device that transmits/receives computer data through a communications channel such as radio or telephone lines. It also changes signals received from the phone line back to digital signals before passing them to the receiving computer. nonvolatile memory (NVRAM) User-programmable random access memory whose data is retained when power is turned off. On the U.S. Robotics modem, it includes four stored phone numbers and the modem settings. off/on hook Modem operations that are the equivalent of manually lifting a phone receiver (taking it offhook) and replacing it (going on-hook). 96
online fall back/fall forward A feature that allows high-speed, error-control modems to monitor line quality and fall back to the next lower speed in a defined range if line quality diminishes. As line conditions improve, the modems switch up to the next higher speed. originate mode The mode used by your modem when initiating an outgoing call to a destination modem. The transmit/receive frequencies are the reverse of the called modem, which is in answer mode.
parity A simple error-detection method that checks the validity of a transmitted character. Character checking has been surpassed by more reliable and efficient forms of error checking, including V.42 and MNP 2-4 protocols. Either the same type of parity must be used by two communicating computers, or both may omit parity. protocol A system of rules and procedures governing communications between two or more devices. Protocols vary, but communicating devices must follow the same protocol in order to exchange data. The format of the data, readiness to receive or send, error detection and error correction are some of the operations that may be defined in protocols.

Industry Canada (IC) This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus set out in the interferencecausing equipment standard entitled Digital Apparatus, ICES-003 of Industry Canada. Cet appareil numrique respecte les limites de bruits radiolectriques applicables aux appareils numriques de Classe B prscrites dans la norme sur le matriel brouilleur: Appareils Numriques, NMB-003 dicte par l'Industrie Canada. UL Listing/CUL Listing This information technology equipment is ULListed and CUL-Listed for use with UL-Listed personal computers that have installation instructions detailing user installation of card cage accessories. 103
Connecting to the Telephone Company It is not necessary to notify the telephone company before installing the modem. However, the telephone company may request the telephone number(s) to which the U.S. Robotics modem is connected and the regulatory information printed in this section. Be sure that the telephone line you are connecting the modem to is a standard analog line and not a digital (PBX), party, or coin telephone line. If the modem is malfunctioning, it may affect the telephone lines. In this case, disconnect the modem until the source of the difficulty is traced. Fax Branding The Telephone Consumer Protection Act of 1991 makes it unlawful for any person to use a 104
computer or other electronic device, including fax machines, to send any message unless such message clearly contains in a margin at the top or bottom of each transmitted page or on the first page of the transmission, the date and time it is sent, an identification of the business or other entity, or other individual sending the message, and the telephone number of the sending machine or of such business, other entity, or individual. (The telephone number provided may not be a 900 number or any other number for which charges exceed local or long-distance transmission charges.) In order to program this information into your U.S. Robotics modem, refer to the RapidComm manual on the CD-ROM that shipped with your modem. If youre using a different communications software program, refer to its manual.
Radio and Television Interference This equipment generates and uses radio frequency energy and if not installed and used properly, in strict accordance with the manufacturers instructions, may cause interference to radio and television reception. The modem has been tested and found to comply with the limits for a Class B computing device in accordance with the specifications in Part 15 of the FCC rules, which are designed to provide reasonable protection against such interference in a residential installation. However, there is no guarantee that interference will not occur in a particular installation. If this device does cause interference to radio or television reception, which you can determine by monitoring reception when the modem is installed and when it is removed from the computer, try to

If ComTest recommended COM2/IRQ3 Write COM2 and IRQ3 somewhere where it will be handy during software installation. Go to How to Change the Modems Settings on page 10. If ComTest recommended COM3/IRQ4 or COM4/IRQ3 Do not use either of these settings. While the COM port part of the setting is acceptable (ComTest only recommends COM ports that are not being used), the IRQ part of the setting is not acceptable. When ComTest recommends either COM3/IRQ4 or COM4/IRQ3, the IRQ in the setting is being used by another accessory. You could use the suggested IRQ for the modem, but you run the risk that the modem and/or the other accessory sharing the IRQ might not work properly.
If you do not have a sound card, use COM3/IRQ5. Write COM3 and IRQ5 somewhere where it will be handy during software installation. You will have to change the settings on your modem. Go to How to Change the Modems Settings on page 10. If you do have a sound card, use COM2/IRQ3. To use this setting, you have to first disable your computers second serial port (COM2). This is a pronged socket on the back of your computer. Go to your computer manufacturers manual. Find out how to disable the COM port. Find out which of the sockets on the back of your computer is the second serial port. If you have something plugged into that port, find out if you can plug it in somewhere else. Any accessory plugged
into that port will not work after the port has been disabled. Then return to this point in this manual to continue. After disabling COM2, you can use the COM2/IRQ3 setting. Write COM2 and IRQ3 somewhere where it will be handy during software installation and go to How to Change the Modems Settings on page 10. If ComTest reports that You do not have any available COM ports and/or IRQs We recommend you disable COM1 or COM2. When you disable one of these COM ports, you can use it and its default IRQ for your modem. Go to your computer manufacturers manual. 9
Find out which socket is COM1 and which is COM2. If nothing is plugged into either port, you may choose either of the ports to disable. Your computer manufacturers manual will tell you how to disable the COM port. If one port does not have anything plugged into it, note if the port is COM1 or COM2. This is the port youll want to disable for your modem. If both ports are being used, you may be able to attach one of the plugged-in accessories elsewhere so that you can disable its COM port. The accessory will not work once its port is disabled. If youve disabled COM1, you can now use the COM1/IRQ4 setting. Write it down somewhere where it will be handy during 10

software installation. Go to How to Change the Modems Settings (on this page). If youve disabled COM2, you can now use the COM2/IRQ3 setting. Write the setting down somewhere where it will be handy during software installation.
How to Change the Modems Settings
1. Always touch an unpainted metal part of your computer (the back is usually unpainted) to discharge static electricity before handling the modem. Static can damage your modem. Then take the modem out of its plastic bag. 2. Find the COM and IRQ jumper shunts (small black plastic pieces) on your
modems jumper pins (see the following diagram).
TIP: Grasp the jumper shunts with
a tweezers or needle-nosed pliers. DO NOT grasp too firmly, as you may crush the jumper shunts. If a jumper shunt seems stuck, gently rock it back and forth as you lift. Do not touch any other part of the modem or your computer with the tweezers/pliers. A jumper shunt needs to be sitting on both jumper pins in order to effectively set the modem to the desired setting.
3. To change the COM port and IRQ settings, you need to reposition the jumper shunts on the COM port and IRQ pins. To do this, lift the jumper shunts off the pins.
4. Move the jumper shunt to the new setting. The COM port setting can involve one to three shunts. The four possible COM port settings are as follows:

COM 1 COM 2

How to Insert the Modem into the Computer
NOTE: Before installing your
modem, write its serial number somewhere where it will be handy during software installation. (Youll find the serial number underneath the bar code on the white sticker on the modem and on the outside of the box the modem came in.) If you ever need to call our customer support department, a customer support representative will ask you for the serial number. This will help him or her identify your modem.

COM 3 COM 4

Unlike most COM port settings, the IRQ setting involves only one jumper shunt. Simply move the jumper shunt to the pins labeled with the IRQ you need.
1. Turn off your computer and unplug it from the electrical outlet. 2. Unplug any peripheral devices (printer, monitor, keyboard, mouse, etc.) from the computer.
TIP: Before you unplug anything,
label the cords or make a sketch of how things are connected. This can be helpful when you plug things back in later.
3. Remove the screws from your computers cover and then remove the cover, as shown in the following diagrams. Your computer may differ in appearance from these diagrams, but the basic principle for removing the cover should be the same. Contact your computer manufacturer or review their manual if you need further instructions.

NOTE: The following instructions
apply to Windows 3.x and Windows 95 users. However, only Windows 95 screens are shown.
NOTE: If you have an older
version of RapidComm Voice software installed on your system, uninstall it before continuing.
1. From the Windows 95 desktop, click the Start button and then click Run.
3. You will briefly see a screen that looks like this.
4. When you are asked if you wish to run the Setup Wizard, click Yes. 2. In the text box, type D:\setup.exe. (If your CD-ROM drive has a letter name other than D, type that letter in place of D.)
5. This is the Setup Wizards Welcome screen. After reading the screen, click Next.
NOTE: Check the COM port setting against the setting you wrote down during the hardware installation.
6. When you see the following screen, select your modem from the list and select the correct COM port setting in the Port box. Then click Next.
7. When you see the next two screens, fill in the blank boxes with the appropriate information, using the TAB key to move between fields. Click Next on each screen when you have filled in all of the necessary information.
8. You will see the following screen as the Setup Wizard creates a U.S. Robotics Connections program group.
9. Next, the Setup Wizard looks for Netscape Navigator on your system.
If the Setup Wizard does not find Netscape Navigator, it searches for Microsofts Internet Explorer. If the Setup Wizard does not find Internet Explorer, it will automatically install the application later in the Setup Wizard process. 36
10.The next screen introduces the U.S. Robotics Registration Wizard. After you read the screen, click Next. Read through each of the next two screens and verify or correct the information you typed earlier. Click Next on each screen to move on.
11. When you see this screen, you are ready to register your new modem. Click By Modem. We recommend you choose the By Modem option because its a great way to verify that your Sportster modem is correctly installed.
12.When you see this screen
If you need to dial a prefix (such as 9) to make a call outside your building, type the prefix before the 1 in the Prefix box and then click Dial. If the modem still does not dial the number properly, you may need to insert a comma between the prefix and the 1 to force the modem to pause.
If you do not need to dial a prefix, simply click Dial. 13.You will see a screen indicating that the registration information has been sent (see circled text in the screen below).
NOTE: If the Setup Wizard detected Internet Explorer on your system during the setup process, your computer will launch the Connections CD-ROM when you click OK. Continue at step 15. If the Setup Wizard DID NOT detect Internet Explorer on your system earlier in the setup process, it will launch the Internet Explorer installation utility after you click OK. When you see the following screen, click Install Internet Explorer and follow the on-screen instructions to complete the installation of the software.

14.The next screen indicates that the Setup Wizard is finished. Click OK to launch the Connections CD-ROM.
Windows 3.x users: Windows will restart. When your desktop reappears, you will see a Connections icon (shown below) in the Connections program group. Double-click the icon to launch the CD.
At the end of the installation process, you will see the following screen. Click Yes.
Windows 95 users: Windows will restart and the Connections CD will launch automatically upon restart. 40
15.When the main Connections menu appears, click Business & Productivity on the menu on the left hand side of the screen (circled below).
16.On the Business & Productivity menu is a RapidComm Voice button (circled in the following screen shot). RapidComm Voice is the fax/data/voice software you can use to send faxes directly from your desktop, transfer files electronically, set up multiple voice mail boxes, or dial into a BBS. Click RapidComm Voice.
17. The next screen contains another menu on the right hand side of the screen. Included on the menu is a Learn More & Get Software button (circled in the screen image below). Click this button.
18.The next screen displays information about the RapidComm Voice software. When you are ready to install the RapidComm Voice software, click Install (circled in the lower left hand corner of the following screen image).
NOTE: If you are using Netscape Navigator to view your Connections CDROM, you may be asked to save the applications installer to your computer when you click the Install button. Note the installers file name and its location on your computer. To run the installer or demo, find the file on your computer and double-click it. The installer will start.
19.The next screen is the first of the RapidComm Voice Setup screens. When this screen appears, make sure the location shown in the text box is where you would like the files copied to and then click Install. If you wish to copy the RapidComm Voice files to a different
directory, type that location in the text box before clicking Install.
20.You will see this screen as files are copied.
This screen marks the end of the RapidComm Voice installation. Click OK to return the Connections.
21.When you see this screen, click either or No. Yes 23.Click Exit (circled in the following screen image).

5. The program will now determine if the selected modem is software upgradable. Non-Upgradable Modems If your modem IS NOT software upgradable, the program will display the following screen.
Click U.S. Robotics if your modem is a U.S. Robotics modem to learn more about your upgrade options. 59
Click Other to learn more about how to purchase a U.S. Robotics x2 modem. Upgradable Modems If the modem IS software upgradable, you will see the following screen.
to upgrade a 33.6 kbps modem to 56 kbps code or click Update my modems code to update your modem with the most recent version of its original code. Then click Next. 6. The next screen you will see is the order information screen. Users who are purchasing a 56K upgrade will see a screen that includes a credit card information query. Users who are updating their modems code will see a personal information query screen. Fill in the screen with the appropriate information and then click Next.
Click Dial U.S. Robotics (which should be the default selection) in the pull-down menu. Click Upgrade to x2 Technology if you wish 60
7. The following screen dials the U.S. Robotics Update Server. Click Tone or Pulse dialing as necessary. If you normally dial a prefix (such as 9) to dial out on your phone line, type that prefix before the 1 in the Prefix box. Then click Dial.
NOTE: Your screen may show a
different number in the Number field.
8. Once connected, the server will compare available upgrades with the current code in your modem. If they differ, the server will automatically initiate the download procedure. NOTE: Users purchasing a 56K upgrade are asked if the charge is acceptable (see the following screen image). Unless you have already been charged for an upgrade, click Yes to continue. If you have already been through this process once before, DO NOT click Yes. Click No and call Customer Support at 847-982-5151. (The price of the upgrade is subject to change and includes applicable taxes.)
NOTE: If you do not have the most up
to date.inf file for your modem (the file that helps Windows correctly identify your modem), you will see the following screen as the Modem Update Wizard automatically downloads the file.
9. You will see this screen as the Wizard downloads the file for your modem.
WARNING! To avoid the risk of
damaging your modem, DO NOT turn off the modem while it is being updated. 11. When updating is complete, the progress bar will be full and an Update/Upgrade Complete message appears. Click Next.
10.When the download is complete, the modem disconnects from the server. The words Downloading file change to Upgrading or Updating , depending on whether you are upgrading or updating your modem. A new progress bar appears. This indicates that your modems code is being updated. 63

12.You will see a Congratulations! screen. Click Details.
13.Click OK once you verify that the process was a success. When you return to the Congratulations! screen, click Finished.

Congratulations!

Enjoy the benefits of your updated Sportster modem!

USING MODEM STATION

What Does Modem Station Do?
Modem Station provides a simple to use interface that makes communicating with your modem even easier. Modem Station allows you to point and click your way through configuration. Modem Station can automatically detect your modem and provide you with all the technical information you need, whenever you need it! You may want to tweak your modem for optimum performance. Youd rather be surfing the Internet.

Installing Modem Station

If you did not install Modem Station when you first installed the Connections CD, please follow these instructions. 1. Insert the Connections CD into your CDROM drive. 2. Double-click the My Computer icon on your desktop. 3. Double-click the CD-ROM icon. 4. Double-click the USR Tools folder. 5. Double-click the umssetup icon.

Why Modem Station?

Modem commands can be confusing and difficult to memorize. Communications software often needs technical information about your modem.
6. You will be asked whether you wish to install Modem Station. Click Yes. 7. Wait a few moments for the Installation Wizard to load. 8. After reading the information on the Welcome screen, click Next.
9. When you see this screen, click Next to accept the default directory or click Browse to change directories.
10.Click Next on the following screen to accept the default program folder. You can place Modem Station in an existing folder by selecting one from the list.
11. When you see the following screen, click Finish to complete the installation.
If this is the first time youve installed Modem Station, you may be asked to restart your computer.

Starting Modem Station

1. If you didnt start Modem Station from the Setup program, please start it now. 2. Click Windows Start button and then point to Programs. Click U.S. Robotics Modem Station (or the folder you selected during installation). 3. Click the Modem Station icon. This brings up the main menu.
The main menu gives you direct access to the following options: DETECT NEW MODEMS TERMINAL MODEM CONFIGURATOR ABOUT CONTACT/SUPPORT
responses. You can use Terminal to dial up BBSs. In addition, you can configure your modem using Terminal. However, it is much easier to use the Modem Configurator. MODEM CONFIGURATOR Modem Configurator provides an easy-to-use interface for entering hard to remember commands. Use Modem Configurator for troubleshooting, initial configuration, and tuning your modem for optimum performance. Using the options available in Modem Configurator, you can control nearly every aspect of your modems performance. We will discuss Modem Configurators options in more detail in later sections. ABOUT The About option provides copyright and version information. 69

WARNING! Use caution

when changing connection settings. Improper settings may cause your modem to function incorrectly, disconnect, or fail to connect at all.
DIALING/ANSWERING The next screen allows you to adjust how your modem initiates and receives calls.

TECHNICAL STUFF:

Negotiation is the noise we hear when two modems connect. The modems exchange information about their respective protocols and configurations. Once they agree on the fastest protocol they can both handle, transmission begins. STORED NUMBERS The Stored Numbers screen displays the phone numbers currently stored in your modems memory. Use this screen to edit or add numbers stored in the modems memory.
Using this screen, you can configure the following dial settings: 80 WAIT FOR CARRIER AUTO-ANSWER # OF RINGS SPEAKER OPERATION DIALING METHOD SPEAKER VOLUME
You can change stored numbers by highlighting them and then typing the new numbers in their place. Once you store your numbers, you can dial them by entering this command from Terminal Mode: ATDS0, ATDS1, ATDS2, etc. Your U.S. Robotics modem comes with one phone number already stored in Position 0. If you havent changed the default, typing ATDS0 will automatically dial the U.S. Robotics BBS. You will want to change this if you are using a dumb terminal or online listing service, of course. Once you enter the numbers you wish to store, click Save to Modem to store them. Click Exit to return to the Main menu. The last option, Restore Defaults, resets your modem to factory specifications. This option is 81
To store a number in your modems memory, simply click in one of the entry boxes. Type in the phone number exactly as you would dial it. NOTE: Position Zero has a special feature. You can set your modem to automatically dial this number when your computer is turned on or when it is reset. This is very useful if you are using your modem with a dumb terminal or know that you need to connect to a specific bulletin board or listing service.
available from many of the screens within Modem Station. When you click Restore Defaults, you will see a confirmation screen asking if you are sure you want to restore defaults. Click OK to proceed.
We devote a separate section to the Extended Information screens so that we can explain what youll see (and why it is important to you) as fully as possible. There are a series of commands used to obtain detailed information from U.S. Robotics modems. Extended Information provides a convenient way to get that important information without memorizing the commands. From the Detect New Modems screen, click Extended Information. The Extended Information screen provides access to the following information about your modem: ROM CHECKSUM PRODUCT ACTIVE PROFILE STORED PROFILE

your Courier documentation for instructions on configuring these special features. We hope that you enjoy exploring the world of information and entertainment your new Sportster modem will open up for you and that Modem Station will make using and configuring your new modem as simple as possible. Remember: If you have any questions or problems, feel free to visit one of our many online forums. For answers to specific questions, be sure to visit our World Wide Web support site at www.usr.com/home/online/main.htm, or try our BBS (847-982-5092).
TROUBLESHOOTING AND ONLINE HELP RESOURCES
PROBLEM DIAGNOSIS POSSIBLE SOLUTION
The computer or Your modem might not Make sure the modem is turned on. The power switch is on top of external software will not be turned on. modems. The CS light on the front panel should be lit. If you installed an recognize the internal modem, it should power up when the computer is turned on. modem. When entering commands in a terminal program, type in all upper case (AT) or You may not be entering all lower case (at). modem commands in the proper manner while in terminal mode. WINDOWS 95 USERS: Uninstall the modem from your computer. In Device You may have a COM Manager, determine what COM port and IRQ settings are free on your system. Set the jumper shunts on your modems jumper pins to these free settings, port/IRQ conflict. using the diagrams below as a guide. If no IRQ setting is available, you may need to move a device off of an IRQ in order to free it for use by your modem.
TROUBLESHOOTING AND ONLINE H ELP RESOURCES

PROBLEM

The computer or software will not recognize the modem (cont.). The modem displays double characters on your monitor. The modem wont go off hook to dial or doesnt answer the phone.

DIAGNOSIS

You may have a COM port/IRQ conflict (cont.). Both the modems and softwares local character echoes are turned on. You may have plugged your modems phone cord into a digital line. You might have a bad phone cord connection to your modem. You may have devices between the modem and the phone jack. You may have a poor line connection.

POSSIBLE SOLUTION

Make sure you have the correct COM port and IRQ settings in your software and/or in the Windows Device Manager. Disable Local Echo in your software OR on your modem (not both). Turn local echo off on the modem by typing ATE0 and pressing ENTER in your softwares terminal mode. To turn the local echo off in the software, refer to its documentation. Plugging your modems phone cord into a digital phone line can damage the modem. Call your phone company if you are unsure whether or not your phone line is digital. The phone cord should be plugged into the TELCO jack on the modem and an analog wall phone jack. The phone cord should not exceed 12 feet in length. Use the phone cord included with your modem if possible. There should be no line splitters, fax machines, or other devices between the modem and the wall jack. Place the call again. Calls are routed differently each time. To verify a valid phone connection, enter RapidComms Terminal mode, type ATX3DT18479825092 (the 3Com BBS), and press ENTER. This string bypasses the dial tone, allowing a connection if the modem is functioning properly.

call. In order to save both time and expense, you should do the following before calling: 1. Click the Windows 95 Start button. 2. Point to Programs and then click RapidComm Voice. (If you have not installed RapidComm Voice, see the section title Software Installation and Testing on page 33.) 3. Enter RapidComm Voices terminal mode by clicking the Terminal button. 4. Type ATI7 and press ENTER. 5. The information that appears will be useful to the technical support representative who attempts to troubleshoot your problem when you call. Select Print from the File menu or leave the information on screen. Hotline (847) 982-5151 100
(Hours: 8:00 am - 6:00 pm CST) Priority No-Hold Service 3Com also staffs its own 900 fee-based number for immediate assistance. These lines are staffed from 8 a.m. - 6 p.m. CST Monday through Friday. No-Hold line 900-555-USR1 There is a $1.50 per minute charge which will appear on your local phone bill. You must be 18 or older or have parental permission. (Service not available in Canada.)
Are You Still Having Problems?
Review this manual. Call or visit your modem dealer. They may be able to assist you. This is much
more efficient and time-saving than returning the modem to U.S. Robotics. If your dealer can't help you, contact 3Com Customer Support. When you call, specify your modem serial number (found on the modem and on the outside of the box), the software being used, and, if possible, have the contents of your ATI7 screen available.
If You Need to Return the Modem to Us
Contact 3Com Customer Support. If the support representative determines that you need to return the modem, you will receive an SRO (Service Repair Order) number. You must have an SRO number before returning the modem to us. Ship the unit, postage paid, in a strong box made of corrugated
cardboard with plenty of packing material. DO NOT send the modem back in the original box. Send ONLY the modem (NOT the power supply, manuals, CD-ROM, etc.). Include your SRO number, name, and address on the shipping label as well as inside the package. If possible, send the package via a courier capable of tracking the progress of the shipment. Ship to the following address: 3Com Attn: RMA SRO# 6201 W. Oakton, East Dock Morton Grove, IL 60053
RapidComm Troubleshooting Tips
PROBLEM: The lights in the RapidComm Voice softwares modem light monitor do not correspond to the actual lights on an external modem. DIAGNOSIS: Under certain circumstances, the modem light monitor does not correctly report the activity of the modem. We are aware of this problem and are working to rectify the situation in upcoming versions of the software. PROBLEM: The station ID works intermittently. DIAGNOSIS: Under certain circumstances (including receiving a fax), the station ID may not work properly.

GLOSSARY carrier The basic signal altered or modulated by the modem in order to carry information. character A representation, coded binary digits of a letter, in , number, or other symbol. characters per second (CPS) A data transfer rate generally estimated frombit rate the and thecharacterlength. For example, at 2400 8-bit bps, characters with start/stop bits(for a total of ten bits per character) will be transmitted at a rate of approximately 240 characters per second ( Someprotocols such as cps). , error-control protocols, employ advanced techniques such as longer transmission frames and data compressionto increase cps. class 1 and 2.0 International standards used by fax application programs and faxmodems for sending and receiving faxes. cyclic redundancy checking (CRC) An error-detection technique consisting of a test performed on each block or frame of data by both sending and receiving modems. The sending modem inserts the results of its tests in each data block in the form of a CRC code. The receiving modem compares its results with the received CRC code and responds with either a positive or negative acknowledgment. data communications The transmission or sharing of data between computers via an electronic medium. data compression table A table containing values assigned for character each during a call under MNP5 data compression. Default values in the table are continually altered and built during each call: The longer the table, the more efficient throughput gained.
GLOSSARY data mode Mode used by a modem when sending and receiving data files. DCE Data Communications (or Circuit-Terminating) Equipment, such as dial-up modems that establish and control the data link via the telephone network. default Any setting assumed, at startup or reset, by the computer's software and attached devices. The computer or software will use these settings until changed by the user or other software. detect phase In theITU-T V.42 error-control protocol, the first stage in establishing if both modems attempting to connect have V.42capability. dictionary The term used for compression codes built byV.42bis the data compression algorithm. digital loopback A test that checks the modem's RS-232 interface and the cable that connects the terminal or computer and the modem. The modem receives data (in the form of digital signals from the computer or terminal, and immediately ) returns the data to the screen for verification. digital signals Discrete, uniform signals. In this manual, the term refers to the binary digits0 and 1. DTE Data Terminal (or Terminating) Equipment. A computer that generates or is the final destination of data. duplex Indicates a communications channel capable of carrying signals in both directions. See duplex, full duplex. half

&H3 &In

Hardware and software flow control
Sets Receive Data (RD) software flow control (see also &Rn). &I0 Software flow control disabled &I1 XON/XOFF signals to your modem and remote system &I2 XON/XOFF signals to your modem only
&Kn Enables/disables data compression. &K0 Data compression disabled &K1 Auto enable/disable
&K2 Data compression enabled

&K3

MNP5 compression disabled
&Mn Sets Error Control (ARQ) for connections at 1200 bps and higher. &M0 Normal mode, error control disabled &M1 Reserved &M2 Reserved &M3 Reserved &M4 Normal/ARQ &M5 ARQ mode &Nn Sets connect speed. If connection cannot be established at this speed, the modem will hang up. Sets ceiling connect speed if &Un is greater than 0. See &Un.
&N0 &N1 &N2 &N3 &N4 &N5 &N6 &N7 &N8 &N9 &N10 &N11 &N12 &N13 &N14 &N15 &N16
Variable rate 300 bps 1200 bps 2400 bps 4800 bps 7200 bps 9600 bps 12,000 bps 14,400 bps 16,800 bps 19,200 bps 21,600 bps 24,000 bps 26,400 bps 28,800 bps 31,200 bps 33,600 bps

&Pn

Sets pulse (rotary) dial make/break ratio. &P0 U.S./Canada ratio, 39%/61% &P1 U.K. ratio, 33%/67%

&Tn

&Rn Sets Receive Data (RD) hardware flow control, Request to Send (RTS) (see also &Hn). &R0 Reserved &R1 Modem ignores RTS &R2 Received Data to computer only on RTS &Sn Controls Data Set Ready (DSR) operations. &S0 DSR override; always ON &S1 Modem controls DSR
Begins test modes (used in conjunction with s register 18). &T0 Ends testing &T1 Analog Loopback &T2 Reserved &T3 Local Digital Loopback &T4 Enables Remote Digital Loopback &T5 Prohibits Remote Digital Loopback &T6 Initiates Remote Digital Loopback &T7 Remote Digital with self-test and error detector

&T8

Analog Loopback with self-test and error detector

&Un

Sets floor connect speed when &Un is set greater than 0. &Nn is the ceiling connect speed. See &Nn. &U0 Disabled &Ubps &Ubps &Ubps &Ubps &Ubps &Ubps &U7 12,000 bps &U8 14,400 bps &U9 16,800 bps &U10 19,200 bps &U11 21,600 bps

Register Default

S10 (cont.)
A better alternative is to ask your phone company how to temporarily disable call waiting (usually *70W). For example: ATDT *70W phone number. Note: If you set S10 = 255, the modem will not hang up when carrier is lost. Dropping DTR hangs up the modem.

S11 S12 S13

Sets the duration and spacing, in milliseconds, for tone dialing. 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 Reset when DTR drops. Reset non-MNP transmit buffer from 1.5K to 128 bytes.* Set backspace key to delete. On DTR signal, auto dial the number stored in NVRAM at position 0.

S13 (cont.)

Bit Value Result At power on/reset, Auto Dial the number stored in NVRAM at position 0. Reserved Disable quick retrains. Disconnect on escape code.
* The 1.5K-byte non-ARQ buffer allows data transfer with Xmodem- and Ymodem-type file transfer protocols
without using flow control. The 128-byte option lets remote users with slower modems keep data youre sending from scrolling off their screens. When remote users send your computer an XOFF (Ctrl-S) and you stop transmitting, the data in transit from your modems buffer doesnt exceed the size of their screen. This is also very helpful in situations when a remote modem/printer application is losing characters.
Bit-mapped register setup. To set the register, see instructions for S13. Bit Value Result Disable ARQ/MNP for V.22. Disable ARQ/MNP for V.22bis. Disable ARQ/MNP V.32/V.32bis/V.32terbo. Disable MNP handshake. Disable MNP level 4. Disable MNP level 3.

S15 (cont.)

Bit Value Result MNP incompatibility. Disable V.42 operation. To disable V.42 detect phase, select the total of the values for bits 3 and 7.
Bit-mapped register setup. To set the register, see instructions for S13. Bit Value Result Reserved Reserved Touch tone test. Use internal test pattern. Test timer for &T loopback testing. Sets the time in seconds of testing before the modem automatically times out and terminates the test. When set to 0, the timer is disabled. Valid range is 1-255.
Sets the duration, in minutes, for the inactivity timer. The timer activates when there is no data activity on the phone line; at time-out the modem hangs up. S19 = 0 disables the timer. Sets the length, in 10-millisecond units, of breaks sent from the modem to the computer; applies to MNP or V.42 mode only.

S19 S21

S22 S23 S19 20
Stores the ASCII decimal code for the XON character. Stores the ASCII decimal code for the XOFF character. Sets the duration, in hundredths of a second, that DTR must be dropped so that the modem doesnt interpret a random glitch as a DTR loss. (Most users will want to use the default; this register is useful for setting compatibility with older systems running under older operating software.) Bit-mapped register setup. To set the register, see instructions for S13. Bit