T E S T I N G   Y O U R   M O D E M
          
          After you hook up your modem, you will want to test it to
          make sure you are connected to the correct COM port. Make
          sure you have all the cables hooked up. One of the most
          common mistakes is plugging the phone line into the wrong
          jack on the modem. Read the modem instructions carefully.
          If you do have it plugged into the wrong jack, you can
          easily correct the situation by trying the other jack. If
          you have an external modem, make sure you turn your modem
          on. An internal modem is powered by your PC's power
          supply. This means that when you turn on your computer,
          an internal modem will automatically be powered on.

          The following test will make your modem howl. External
          modems can be particularly loud (depending on how the
          volume is set). If a loved-one is sleeping nearby, you may
          wish to wait for a more appropriate time. The next two
          commands should be issued in either lower or upper case
          letters. Do not mix upper and lower case letters when issuing
          one of these commands. Suppose you believe that your modem is
          using COM4. With all the power on, issue the following command
          at the DOS prompt:
          
                                echo ata > com4 <ENTER>
          
          If your modem is connected to COM4, you should hear a
          dial tone. If you are testing for another COM port, make
          the appropriate change in the command (i.e. COM2, COM3,
          etc.). Some external modems will squeal like a stuck pig
          when you issue the above command. To turn the shrieking
          noise off, issue a command like the following:
          
                                echo ath > com4 <ENTER>
          
          These commands make use of the basic AT Hayes command
          set, which has been adopted by modem manufacturers as the
          industry standard. A modem that is Hayes compatible can
          use this basic Hayes command set. Don't buy a modem if it
          isn't Hayes compatible. The command letters AT wake up
          the modem and initialize it.  
          
          The first command used ATA, which told the modem to
          answer an incoming call. The second command contained
          ATH, which tells the modem to hang up the phone. 
          
          If you have an external modem and don't like the concept
          of having your modem howl, you can issue a command that
          will only make your modem lights flash. Suppose you have
          an external modem and the baby is asleep. You turn your
          machine and modem on. Make sure all the cables are
          connected. You suspect that the modem is connected to
          COM2. Then issue the following command at the DOS prompt:
          
                                echo at > com2 <ENTER>
          
          Before you press the <ENTER> key, look at the modem
          lights. If the external modem is connected to COM2, then
          the lights will flash when you issue the above command.
          This offers a test to see if the external modem is
          connected to the COM port that you think it is. If the
          modem lights didn't flash, try changing the command to
          reflect other COM ports (COM1, COM3, COM4). The AT means
          ATTENTION modem.
          
          For more information about the basic AT Hayes command
          set, and more modem tests, see the section on AT command
          set usage.
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