//---------------------------------------------------------------
// EXAMPLE EX8.C :  Demonstrate the SWITCH statement.
//
// 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 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 = 0x3F & inportb(KEY_PB);
switch (X) {
   case 1:  outportb(KEY_PC, 1);
            break;
   case 2:  outportb(KEY_PC, 2);
            break;
   case 3:  outportb(KEY_PC, 3);
            break;
  default:  outportb(KEY_PC, 4);
	    break;
   }
}