Format
#include <conio.h> /* also in <builtin.h> */ int _inp(const unsigned int port);
Language Level: Extension
_inp reads a byte from the specified input port.
The port number must be an unsigned int value in the range 0 to
65 535 inclusive.
Note: _inp is a built-in function, which means it is implemented as an inline instruction and has no backing code in the library. For this reason:
You can run code containing this function only at ring zero. Otherwise, an invalid instruction exception is generated.
Return Value
_inp returns the byte value as an integer
that was read from the specified port. There is no error return
value, and _inp does not set errno.
![]()
_inpw -- Read
Unsigned Short from Input Port
_inpd -- Read
Doubleword from Input Port
isatty -- Test
Handle for Character Device
_outp -- Write
Byte to Output Port
_outpw -- Write
Word to Output Port
_outpd -- Write
Double Word to Output Port
<builtin.h>
<conio.h>