; __________________________________________________
; |          "Mid Air" Oscillating LED Sign         |
; |By Josh Wardell      April, 1999      for CSE 398|
; |MPASM asm for the Microchip 16C84 microcontroller|
; |(C) 1999 Josh Wardell     http://www.jwardell.com|
; |_________________________________________________|

		list    p=16C84
		radix   hex
		include "p16c84.inc"

        cblock  0x0C
		dtime
		tick
		tick2
        endc
                org     0x00
                goto    start

		org	0x04
Intsvc		retfie

initstuff       movlw   0x00
                tris    PORTB
                clrwdt
		movlw	0x18		;delay time
		movwf	dtime
                retlw   0

dsmile		movlw	b'00010000'
		movwf   PORTB
                call    delay2
		movlw	b'00100100'
		movwf   PORTB
                call    delay2
		movlw	b'00100000'
		movwf   PORTB
                call    delay2
		movlw	b'00100100'
		movwf   PORTB
                call    delay2
		movlw	b'00010000'
		movwf   PORTB
                call    delay2
		movlw	b'00000000'
		movwf   PORTB
                call    delay2
		return

djcap		movlw	b'00100001'
		movwf   PORTB
                call    delay2
		movlw	b'01000001'
		movwf   PORTB
                call    delay2
		movlw	b'00111111'
		movwf   PORTB
                call    delay2
		movlw	b'00000001'
		movwf   PORTB
                call    delay2
		movlw	b'00000001'
		movwf   PORTB
                call    delay2
		return

dolow		movlw	b'00110000'
		movwf   PORTB
                call    delay2
		movlw	b'01001000'
		movwf   PORTB
                call    delay2
		movlw	b'00110000'
		movwf   PORTB
                call    delay2
		movlw	b'00000000'
		movwf   PORTB
                call    delay2
		return

dslow		movlw	b'01010000'
		movwf   PORTB
                call    delay2
		movlw	b'00101000'
		movwf   PORTB
                call    delay2
		movlw	b'00000000'
		movwf   PORTB
                call    delay2
		return

dhlow		movlw	b'01111111'
		movwf   PORTB
                call    delay2
		movlw	b'00001000'
		movwf   PORTB
                call    delay2
		movlw	b'01110000'
		movwf   PORTB
                call    delay2
		movlw	b'00000000'
		movwf   PORTB
                call    delay2
		return

dwcap		movlw	b'00011111'
		movwf   PORTB
                call    delay2
		movlw	b'01100000'
		movwf   PORTB
                call    delay2
		movlw	b'00010000'
		movwf   PORTB
                call    delay2
		movlw	b'01100000'
		movwf   PORTB
                call    delay2
		movlw	b'00011111'
		movwf   PORTB
                call    delay2
		movlw	b'00000000'
		movwf   PORTB
                call    delay2
		return

display     
		;call	dsmile		
                call    delay2
                call    delay2
		call	djcap
		call	dolow
		call	dslow
		call	dhlow
		call	dwcap
                call    delay2
                call    delay2		
                call    delay2		
                call    delay2
                retlw   0


delay           movf    dtime,0
		movwf	tick
delayloop	decfsz  tick,f
                goto    delayloop
                return
                retlw	0

delay2          movf    dtime,0
		movwf	tick2
DL2		call	delay
		decfsz  tick2,f
                goto    DL2
                return
                retlw   0


start           call    initstuff
spin		call    display
		goto    spin
                end