D15mH EQU 17	
D15mL EQU 250	
COLS  EQU PORTB
ROWS  EQU	PORTA
ROW0  EQU %11111110
ROW1  EQU %11111101
ROW2  EQU %11111011
ROW3  EQU %11110111
COLM  EQU %00001111
DR15mH  DS.B 1	
DR15mL  DS.B 1
PDELAY  DS.B 1
KCODE0  DC.B '123A' 
KCODE1  DC.B '456B' 
KCODE2  DC.B '789C' 
KCODE3  DC.B '*0#D' 
            ORG   ROMStart
Entry:
  	LDS	#RAMEnd+1	
  	LDAA	#$FF
	STAA	DDRA		
	STAA DDRT    	
	LDAA #$00
	STAA	DDRB    	
K1:  CLR ROWS  	
  	LDAA COLS 
  	ANDA #COLM 	
  	CMPA #COLM
  	BNE K1      	
K2:  CLR ROWS  	
  	JSR	DELAY	
  	LDAA COLS 	
  	ANDA #COLM 	
  	CMPA #COLM
  	BNE OVER      	
  	BRA K2    	
OVER: JSR DELAY	
  	LDAA COLS		
  	ANDA #COLM	
  	CMPA #COLM	
  	BNE OVER1		
  	BRA K2		
OVER1: LDAA #ROW0 
  	STAA ROWS     
  	MOVB #$08,PDELAY
P1:  DEC PDELAY	
  	BNE P1
  	LDAA COLS 	
  	CMPA #COLM
  	BNE R0      	
  	LDAA #ROW1 
  	STAA ROWS     
 	MOVB #$08,PDELAY
P2  	DEC PDELAY	
  	BNE P2
  	LDAA COLS 	
  	CMPA #COLM
  	BNE R1      	
  	LDAA #ROW2 
  	STAA ROWS     
  	MOVB #$08,PDELAY
P3  DEC PDELAY		
  	BNE P3
  	LDAA COLS 	
  	CMPA #COLM
  	BNE R2      	
  	LDAA #ROW3 
  	STAA ROWS     
  	MOVB #$08,PDELAY
P4  	DEC PDELAY	
  	BNE P4
  	LDAA COLS 	
  	CMPA #COLM
  	BNE R3      	
  	BRA K2    	
R0: 	LDX #KCODE0	
  	BRA FIND		
R1: 	LDX #KCODE1	
  	BRA FIND		
R2: 	LDX #KCODE2	
  	BRA FIND		
R3: 	LDX #KCODE3	
  	BRA FIND		
FIND: ANDA #COLM	
SHIFT: LSRA 		
  	BCC MATCH		
  	INX			
  	BRA SHIFT		
MATCH: LDAA 0,X	
  	STAA PTT		
  	LBRA K1		
DELAY: LDAA #D15mH 	
 	STAA	DR15mH 	
D2:	LDAA	#D15mL	
	STAA	DR15mL	
D1: 	DEC DR15mL	
	NOP
	NOP
	BNE	D1
	DEC DR15mH	
	BNE	D2
    	RTS