ORG 0000H
	AJMP MAIN
	ORG 001BH 
	AJMP INT_0
	ORG 0030H
MAIN:
	MOV 70H,#00H
	MOV 71H,#00H
	MOV 72H,#00H
	MOV 73H,#00H
 
	SETB EA
	SETB EX0

	MOV DPTR,#0FF82H
	MOV A,#0D1H
	MOVX @DPTR,A
WAIT:	MOVX A,@DPTR
	JB ACC.7,WAIT
	MOV A,#00H
	MOVX @DPTR,A
	MOV A,#2AH
	MOVX @DPTR,A	
	LCALL DISP

  LP1:	MOV DPTR,#0FF82H
	MOVX A,@DPTR
	ANL A,#3FH
	JZ LP1	
	LCALL KEY
	JBC F0,START
	AJMP LP1
START:	MOV 30H,#09H
	MOV 31H,#60H
	MOV DPTR,#8300H	
	MOVX @DPTR,A
  
	
INT_0:	MOVX A,@DPTR
	MOV R2,A
	
	MOV R3,30H
	MOV R4,31H
	LCALL MULD
	
	LCALL DV31
	LCALL HBCD
	LCALL TRANS
	LCALL DISP
	
	
	MOV DPTR,#8700H
	MOV A,R2
	MOVX @DPTR,A
  LP2:	MOV DPTR,#0FF82H
	MOVX A,@DPTR
	ANL A,#3FH
	JZ LP2
	LCALL GETKEY	
	CJNE A,#0BH,YY
	AJMP MAIN
YY:	CJNE A,#0CH,RETURN2
	AJMP START	 
RETURN2: RETI

KEY:    
	LCALL GETKEY
	CJNE A,#0AH,RETURN1
	 SETB F0
	AJMP RETURN1
RETURN1:RET
  


;雙字節(jié)乘法子程序H2MUL_SUB,Page 6
;入口條件：被乘數(shù)放在20H,21H;乘數(shù)放在22H,23H；乘數(shù)位數(shù)放在2AH
;出口條件：積數(shù)放在R4,R5,R6,R7
;影響參數(shù)：A,R0,R1,R2,R4,R5,R6,R7 
MULD:	MOV R0,30H;
	MOV R1,31H
	MOV R2,A
	MOV R3,#00H
	MOV R4,#00H
	MOV R5,#00H
	MOV R6,#00H
	MOV R7,#00H
	MOV 2AH,#10H
LOOP_D_M:	MOV A,R4
	ADD A,R4
	MOV R4,A
	MOV A,R5
	ADDC A,R5
	MOV R5,A
	MOV A,R6
	ADDC A,R6
	MOV R6,A 
	MOV A,R7
	ADDC A,R7
	MOV R7,A
	MOV A,R2
	ADD A,R2
	MOV R2,A
	MOV A,R3
	ADDC A,R3
	MOV R3,A
	JNC TO_LOOP0
	MOV A,R4
	ADD A,R0
	MOV R4,A
	MOV A,R5
	ADDC A,R1
	MOV R5,A
	MOV A,R6 
	ADDC A,#00H
	MOV R6,A
	MOV A,R7 
	ADDC A,#00H
	MOV R7,A 
TO_LOOP0:	DJNZ 2AH,LOOP_D_M
	RET


	

DV31: CLR C
	MOV A,R3
	SUBB A,R7
	JC DV30
	SETB OV 
	RET
DV30: MOV R2,#10H 
DM23: CLR C
	MOV A,R5
	RLC A
	MOV R5,A
	MOV A,R4
	RLC A
	MOV R4,A
	MOV A,R3
	RLC A
	MOV R3,A
	MOV F0,C
	CLR C
	SUBB A,R7
	ANL C,/F0
	JC DM24
	MOV R3,A
	INC R5
DM24: DJNZ R2,DM23
	MOV A,R3 
	ADD A,R3
	JC DM25
	SUBB A,R7
	JC DM26
DM25: INC R5
	MOV A,R5
	JNZ DM26
	INC R4
DM26: CLR OV
	RET 



GETKEY: MOV A,#40H
      	MOV DPTR,#0FF82H
	MOVX @DPTR,A
	MOV DPTR,#0FF80H
	MOVX A,@DPTR
	ANL A,#3FH
	MOV R4,A
	RET
	

TRANS: MOV R0,#42H
       MOV R1,#70H
       MOV R7,#03H
  LAST:MOV      A,@R0
       ANL      A,#0FH
       MOV      @R1,A
       MOV      A,@R0
       ANL      A,#0F0H
       SWAP     A
       INC  R1
       MOV      @R1,A
       INC  R1
       DEC R0
       DJNZ R7,LAST
       RET



HBCD: CLR A
	MOV 40H,A
	MOV 41H,A
	MOV 42H,A
	MOV R2,#10H 
HB3: MOV A,R5 
	RLC A
	MOV R5,A
	MOV A,R4
	RLC A
	MOV R4,A
	MOV A,42H  
	ADDC A,42H
	DA A   
	MOV 42H,A
	MOV A,41H
	ADDC A,41H
	DA A
	MOV 41H,A
	MOV A,40H
	ADDC A,40H
	MOV 40H,A 
	DJNZ R2,HB3 
	RET


DISP:  MOV      DPTR,#0FF82H
       MOV      A,#90H
       MOVX      @DPTR,A
       MOV      R1,#70H
       MOV      R7,#04H
       MOV      DPTR,#0FF80H
  LOOP:MOV      A,@R1
       ADD      A,#05H
       MOVC     A,@A+PC
       MOVX     @DPTR,A
       INC      R1
       DJNZ     R7,LOOP
       RET
       DB       3FH,06H,5BH,4FH,66H,6DH
       DB       7DH,07H,7FH,6FH 
	END