//---------------------------------------------------------------
// EXAMPLE EX11.C :  Demonstrate a FUNCTION call - I.
//                   NO parameter passed TO/FROM function delay().
//
// C.P. Diduch, Dec 1999.
//---------------------------------------------------------------
#define	KEY_PA	0x138	// 82C55A port addresses for PA,
#define KEY_PB	0x13A	  // PB,
#define KEY_PC	0x13C	  // PC and the
#define KEY_CON	0x13E	  // Control Register.

#include <conio.h> 	  // conio.h contains prototypes for 
			  // inportb() and outportb(). 
void delay(void);	  // Function definition or prototype.
//---------------------------------------------------------------
void main()
{
char X;

outportb(KEY_CON, 0x82);  // Initialize 82C55A PPI with ports 
			  // KEY_PC and KEY_PA as OP ports and 
			  // port PB as an IP port.
X = 0xAA;
do {
   X = ~X;
   outportb(KEY_PC, X);
   delay();
   }
while (1);
}
//---------------------------------------------------------------
void delay(void) {
unsigned k, Time;

Time = 50000;
for (k = 0; k < Time; k++) {};
}