HOW TO: Change COM Port Mappings by Using the CHANGE PORT Command in Windows 2000 Terminal Services

This step-by-step article describes how to map COM ports for compatibility with MS-DOS-based programs by using the change port command in Windows 2000 Terminal Services.

You can use the change port command to display or change COM port mappings for compatibility with MS-DOS-based programs. Most MS-DOS-based programs support only serial ports COM1 through COM4. You can use the change port command to map a serial port to a different port number so that MS-DOS-based programs can access that serial port.

Note that COM port mappings apply only to the current session. If you log off and then log back on, you must use the change port command to map the COM port again.

Description of the CHANGE PORT Command

The change port command uses the following syntax: The parameters and switches that are used by the change port command are:

• portx=porty: Use these parameters to map COM port x to COM port y.
• /d portx: Use this switch to delete the mapping for COM port x.
• /query: Use this switch to display a list of current port mappings for the current session.

Examples

These are examples of how to use the change port command to change and display COM port mappings:

• To map COM12 to COM2, type the following line at a command prompt, and then press ENTER:
  change port com12=com2
• To display a list of current port mappings, type the following line at a command prompt, and then press ENTER:
  change port /query
• To delete the mapping for COM12, type the following line at a command prompt, and then press ENTER:
  change port /d com12

For more information about the change port command, visit the following Microsoft Web site: