/*bob.c*/
#include <dos.h>
#include <conio.h>
#include <stdio.h>
#include<process.h>


unsigned char selection;

void play_dport(void)
{

static unsigned char a;

/*repeat till a key is pressed*/
while(!kbhit())
{
outportb(0x378, a);
printf("\nDATA port = %X",a);
a++;

sleep(1);
}
getch();
}

void play_cport(void)
{

static unsigned char c;

while(!kbhit())
{
outportb(0x37a, c);
printf("\nCONTROL port = %X",c);
c++;

sleep(1);
}
getch();
}


void dout_cin(void)
{
static unsigned char dout, cin;
outportb(0x37a, 0x04);
 while(!kbhit())
 {
outportb(0x378, dout);
cin=inportb(0x37a) & 0x0f;
printf("\nDATA port = %X, CONTROL port raw = %X, CONTROL port corrected = %X", dout & 0x0f, cin, 0x0b ^ cin);
dout++;
sleep(1);
}
getch();
}

void dout_sin(void)
{
static unsigned char dout, sin;
 while(!kbhit())
 {
outportb(0x378, dout);
sin=inportb(0x379) & 0xf8;
printf("\nDATA port = %X, STATUS port = %X, STATUS port corrected = %X", (dout & 0xf8)>>3, sin>>3, 0x80 & (sin>>3));
dout=dout+8;
sleep(1);
}
getch();
}


unsigned char get_selection(void)
{

		puts( "\nPlay with DATA Port\t\t\tD\n" );
		puts( "DATA port output, CONTROL port input\tC\n" );
		puts( "DATA port output, STATUS port input\tS\n" );
		puts( "CONTROL port output\t\t\tO\n" );
		puts( "Exit \t\t\t\t\tX\n" );


		printf( "Enter selection: " );
		gets( &selection );
		selection |= 0x20;
return selection;
}

main()
{
for(;;){
get_selection();
		switch (selection) {
			case 'd': printf("\nCase D\n");
				  play_dport();
				  break;
			case 'c': printf("\nCase C\n");
				  dout_cin();
				  break;
			case 's': printf("\nCase S\n");
				  dout_sin();
				  break;
			case 'o': printf("\nCase O\n");
				  play_cport();
				  break;
			case 'x': printf("\nBye... Play me again!\n");
				exit(0);

		       default: printf("\nError\n");
}
}

}