_outp, _outpw, _outpd
Important This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here. ArchiveDisclaimer

_outp, _outpw, _outpd

Output a byte(_outp), a word(_outpw), or a double word (_outpd) at a port.

int _outp(
   unsigned short port,
   int databyte 
unsigned short _outpw(
   unsigned short port,
   unsigned short dataword 
unsigned long _outpd(
   unsigned short port,
   unsigned long dataword 


Port number.
databyte, dataword
Output values.

Return Value

The functions return the data output. There is no error return.


The _outp, _outpw, and _outpd functions write a byte, a word, and a double word, respectively, to the specified output port. The port argument can be any unsigned integer in the range 0 – 65,535; databyte can be any integer in the range 0 – 255; and dataword can be any value in the range of an integer, an unsigned short integer, and an unsigned long integer, respectively.


Routine Required header Compatibility
_outp <conio.h> Win 95
_outpw <conio.h> Win 95
_outpd <conio.h> Win 95

For additional compatibility information, see Compatibility in the Introduction.


All versions of the C run-time libraries.

See Also

Console and Port I/O Routines | _inp | Run-Time Routines and .NET Framework Equivalents

© 2015 Microsoft