Change port

Lists or changes the COM port mappings to be compatible with MS-DOS applications.


change port [{portx=porty|/d portx|/query}]


portx=porty : Maps COM port x to porty.

/d portx : Deletes the mapping for COM port x.

/query : Displays the current port mappings.

/? : Displays help at the command prompt.


  • Most MS-DOS applications support only COM1 through COM4 serial ports. The change port command maps a serial port to a different port number, allowing applications that do not support high-numbered COM ports to access the serial port. For example, to map COM12 to COM1 for use by an MS-DOS-based application, type change port com12=com1. Remapping works only for the current session and is not retained if you log off from a session and then log on again.

  • Use change port without any parameters to display the available COM ports and their current mappings.

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