#define ML4OUT 0x400
 #define ML4WRITE *((char *) ML4OUT)
 
 #define IRQSRC 0xDC0
 #define IRQSRCREAD *((char *) IRQSRC)
 #define IRES1 0xDC2
 #define IRES1WRITE *((char *) IRES1)
 #define IRES2 0xDC3
 #define IRES2WRITE *((char *) IRES2)
 
 #define IRQVECT1 0xFFF2
 #define IRQVECT1WRITE *((short *) IRQVECT1)
 #define IRQVECT2 0x3FF2
 #define IRQVECT2WRITE *((short *) IRQVECT2)
 #define IRQHandler_ADR (short) IRQHandler
 
  void irqinit(void); 
 __interrupt void IRQHandler( void );
 
 
 unsigned char KNAPP;
 
 void main(void){
    KNAPP = 0;
    irqinit();
    
   while(1) {
     ML4WRITE = KNAPP;
   }
 }
 
 void irqinit(void) {		//Interrupt init
  
 IRQVECT1WRITE = IRQHandler_ADR;
 IRQVECT2WRITE = IRQHandler_ADR;
 
 IRES1WRITE = 0;		//Clear IRQ-flip-flops
 IRES2WRITE = 0;
 
 __asm(" CLI");
 }


__interrupt void IRQHandler( void ){  // Interrupt handler 

 if (IRQSRCREAD & 1) {
     if(KNAPP < 255)
     KNAPP++;
     IRES1WRITE = 0;	 
 }
 else		
 {   
     if(KNAPP > 0)
     KNAPP--;
     IRES2WRITE = 0;
  }
}