I/O Port Access in Turbo C, Borland C/C++

Turbo C and Borland C/C++ provide access to the I/O ports on the 80x86 CPU via the predefined functions inportb / inport and outportb / outport. 

int inportb(int portid); /* returns a byte read from the I/O port portid */

 int inport(int portid); /* returns a word read from the I/O port portid */

void outportb(int portid, unsigned char value);
                         /* writes the byte value to the I/O port portid */

 void outport(int portid, int value);
                         /* writes the word value to the I/O port portid */

#include <stdio.h>
#include <dos.h>

#define Data    0x378
#define Status  0x379
#define Control 0x37a

unsigned char Bits;

outportb(Data,Bits);   /* output data */

Bits = inportb(Status); /* input data */

Here's my Digital Joystick example

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last updated: 13-Mar-97 Ian Harries <ih@doc.ic.ac.uk>