This procedure is used to initialize a Practical Peripherals 28.8 and 14.4 Baud Modems. The first procedure is for enabling the modem for dialin, and the second is to set the modem up for dial out. There are not many differences, but they are important.

Enabling a modem for dialin

The following commands (less their comments) need to be sent to the modem. The easiest way to do this would be to set the port as an AUX port and use ADUMB to initialize the modem. Set handshaking to none for this exercise. Don't forget to use the AUX command with the correct AUX port the modem is connected to. COM1 is AUX0, COM2 is AUX1, and the first Addon Port is AUX2. You should see an OK after hitting return for each command as an indicator that the modem understood the command.

AT&F0 (Reset the modem to its factory defaults)

ATS0=1 (Answer on first ring)

AT&C1 (DCD tracks carrier)

ATS10=10 (Used if call waiting is on phone line)

AT&D3 (Hang up, reset modem to init state on DTR transistion)

AT&S1 (Assert DSR at handshake start, inhibit durring hangup)

AT&K3 (Enables RTS/CTS flow control)

AT&Q5 (Select V.42 operation - requires flow control)

AT&B0 (Disable automatic retrain function) ATQ1 (Do not return result codes)

AT&W0 (Store current settings in NVRAM register 0)

Once you have configured the modem don't forget to enable RTS and CTS handshaking for the port, as that is what we set the modem up for.

If you use the FORCE command to program your modem please use MODE COMx baud RESET to reset your COM port. Use the number of your port for x and use the baud rate that you just used to program the modem. (If using CDOS use the CCIMODE command.)