/*
   DAn Williams
   Aug 14 2004
   Demo of parallel port access and controll. 
   uses inpout.dll
    Enjoy.
*/
#include <conio.h>
#include <stdio.h>
#include <windows.h>

/* definitions on what port is what base address depends, so use this */
#define LPT1     0x378
#define LPT2     0x278
#define LPT3     0x3BC

/* register offsets */
#define DATA     0
#define STATUS   1
#define CONTROLL 2

#define  BASE_ADDRESS   LPT1   /* this is the address we use (modify here if you need to) */

typedef short _stdcall (*INP32)(short PortAddress);
typedef void  _stdcall (*OUT32)(short PortAddress, short Data);

int main(void) {

    short     value;
        
    HINSTANCE hLib;
    INP32     Inp32;
    OUT32     Out32;
     
/******************** LIBRARY INIT ***********************/
     
    if ((hLib = LoadLibrary("inpout32.dll")) == NULL) {
        printf("Unable to load inpout32.dll, did you copy it to the system folder?\n");
        return 0;
    }
    
    if ((Inp32 = (INP32)GetProcAddress(hLib, "Inp32")) == NULL) {
        printf("Unable to establish handle to input function.\n");
        return 0;
    }
    
    if ((Out32 = (OUT32)GetProcAddress(hLib, "Out32")) == NULL) {
        printf("Unable to establish handle to output function.\n");
        return 0;
    }


/*********************** MAIN CODE **************************/

     //  Write to the data register 
     value = 0x55;
     printf("Writing 0x%2X to port 0x%X...\n" ,value ,BASE_ADDRESS  );
     Out32( BASE_ADDRESS , value );
     
     // Read it back 
     value = Inp32(BASE_ADDRESS);
     printf("\n(Reading) Port %04X = %04X\n", BASE_ADDRESS, value);

     //  Now use a different value 
     value = 0xAA;
     printf("\nWriting 0x%2X to port 0x%X...\n" ,value ,BASE_ADDRESS  );
     Out32(BASE_ADDRESS, value);
     
     // Read it back  
     value = Inp32(BASE_ADDRESS);
     printf("\n(Reading) Port %04X = %04X\n\n", BASE_ADDRESS, value);

 /******************** CLEANUP ******************************/

     // GO FREEE LITTLE LIBRARIES!, GO FREEEEE!!!
     FreeLibrary(hLib);

     // were done.
     printf("Press any key to exit.\n");
     getch();

     return 1;
}