list p=16F84A
#include <p16F84A.inc>
__CONFIG _CP_OFF & _WDT_OFF & _PWRTE_ON & _XT_OSC

 w EQU 0
 f EQU 1
 CBLOCK H'0C'
 W_temp
 Status_temp
 Counter
 Frequency
 Duration
 ENDC
 #define Out PORTB,0
 #define Melody_1 PORTB,6
 #define Melody_2 PORTB,7
 ORG H'0000'
 goto start
 start bsf STATUS,RP0
 movlw B'01010111'
 movwf OPTION_REG
 bcf STATUS,RP0
 clrf PORTB
 bsf STATUS,RP0
 bcf TRISB,RP0
 bcf STATUS,RP0
 goto main
 Wait movf Frequency,w
 movwf Counter
 loop decfsz Counter,f
 goto loop
 return
 First_Melody
 movlw D'250'
 movwf Frequency
 movlw D'2'
 movwf Duration
 call Sound
 movlw D'150'
 movwf Frequency
 movlw D'5'
 movwf Duration
 call Sound
 movlw D'200'
 movwf Frequency
 movlw D'3'
 movwf Duration
 call Sound
 movlw D'250'
 movwf Frequency
 movlw D'3'
 movwf Duration
 call Sound
 return
 Second_Melody
 movlw D'190'
 movwf Frequency
 movlw D'1'
 movwf Duration
 call Sound
 movlw D'135'
 movwf Frequency
 movlw D'1'
 movwf Duration
 call Sound
 return
 Sound clrf TMR0
 sound_again
 bsf Out
 call Wait
 bcf Out
 call Wait
 btfss INTCON,T0IF
 goto sound_loop
 decfsz Duration,f
 goto sound_again
 return
 main btfss Melody_1
 call First_melody
 btfss Melody_2
 call Second_melody
 goto main
 END