SETB P3.3    	;2051 RST LOW
			CALL DELAYL     ;10ms delay
			CALL DELAYL			
			CLR P3.3        ;2051 RST  HIGH 
                                        ;PC SET TO 00H  
			CLR P1.0     	;2051 XTAL1 LOW 
 			SETB P3.6   	;ALE HIGH
			SETB P3.7   	;12V OFF

                        MOV P0,#0FFH
			MOV A,#0H       ;SIGNATURE READ LOGIC
			MOV P2,A
                        MOV A,P0
			CJNE A,#1EH,ERR  
                        MOV 43H,#02H   ;20 PIN IC
			CLR P1.0       ;NEXT ADDRESS 01H
			NOP            ;
			SETB P1.0      ;
			NOP            ;
			CLR P1.0       ;
			
                        MOV A,P0  
			CJNE A,#11H,S3
			MOV 40H,#04H       ;1051
			JMP BEG
	S3:
			CJNE A,#21H,S4
			MOV 40H,#05H       ;2051
			JMP BEG
	S4:
			CJNE A,#41H,ERR
			MOV 40H,#06H      ;4051
			JMP BEG