Debug: o (output)

Sends the value of a byte to an output port.


o port byte-value


port : Required. Specifies the output port by address. The port address can be a 16-bit value.

byte-value : Required. Specifies the byte value you want to direct to port.

?: Displays a list of debug subcommands.


Windows XP does not use this command. It is accepted only for compatibility with MS-DOS files. 

For information about reading the value of a byte from an input port by using i (input) subcommand, see Related Topics.


To send the byte value 4Fh to the output port at address 2F8h, type:

o2f8 4f

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Information that the user must supply


Elements that the user must type exactly as shown

Ellipsis (...)

Parameter that can be repeated several times in a command line

Between brackets ([])

Optional items

Between braces ({}); choices separated by pipe (|). Example: {even|odd}

Set of choices from which the user must choose only one

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Code or program output

Debug subcommands


Command-line reference A-Z

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