LIST	p=16f628a		;processor  16F628A
	include "C:\Program Files\MPLAB\P16f628a.inc"	;radix  DEC

	__config 0x3F10

STATUS      EQU   0x03
PORTA       EQU   0x05
TRISA       EQU   0x85
COUNT1      EQU   0x08
COUNT2      EQU   0x09
RP0         EQU   5
RP1         EQU   6
SWPORT		EQU		0X05 	;port a	
SW1			EQU		0x02	;bit 3, or  ra2





cblock 	0x20 			;start of general purpose registers
		count1 			;used in delay routine
		counta 			;used in delay routine 
		countb 			;used in delay routine
	endc
	
	org	0x0000			;org sets the origin, 0x0000 for the 16F628,
						;this is where the program starts runninggoto main

	MOVLW 0x07			;these two lines are necessary for switch on RA2 to turn off comparitors   
	MOVWF CMCON			;so pin could be used as i/o.  Took me 2 hours to figure this out!
	BSF     0x03,RP0
	BCF		0x03,RP1
	movlw 	0x04		;these lines set bits 0 and 1 as output and bit 2 as input
	movwf 	TRISA		;on port a
	BCF     0x03,RP0
	BCF		0x03,RP1



MAIN    
		MOVLW 0x01
		MOVWF PORTA
	    call DELAY
		BTFSS	SWPORT,SW1	;checks porta, switch 1 and skips next command if set.
		CALL DELAY

		MOVLW 0x02
    	MOVWF PORTA
		call DELAY
		BTFSS	SWPORT,SW1
		CALL DELAY

		GOTO MAIN


DELAY	movlw	d'250'			;delay 250 ms (4 MHz clock) to make run faster or slower change the d'250' setting
	movwf	count1
d1	movlw	0xC7
	movwf	counta
	movlw	0x01
	movwf	countb
Delay_0
	decfsz	counta, f
	goto	$+2
	decfsz	countb, f
	goto	Delay_0

	decfsz	count1	,f
	goto	d1
	retlw	0x00

	END