WRITE_HEX EQU 8104H
WRITE_DATA EQU 8102H
WAIT_KEY EQU 811CH
LCD_CLR EQU 810CH
WRITE_INSTR EQU 8106H
LED EQU P1.7
DELAY_100MS EQU 8112H

LJMP    START
    ORG 100H

START:
LCALL LCD_CLR
LCALL WAIT_KEY


LOOP:


MOV R0,A          ;dodawanie
LCALL LCD_CLR
LCALL WRITE_HEX
MOV A,#'+'
LCALL WRITE_DATA
LCALL WAIT_KEY
MOV R1,A
LCALL WRITE_HEX
MOV A,#'='

LCALL WRITE_DATA

MOV A, R0
ADD A, R1

MOV B,#10
DIV AB
SWAP A
ADD A,B
LCALL WRITE_HEX




MOV A,#0C0H      ; odejmowanie
LCALL WRITE_INSTR
MOV A,RO
LCALL WRITE_HEX
MOV A,#'-'
LCALL WRITE_DATA
MOV A,R1
LCALL WRITE_HEX
MOV A,#'='
LCALL WRITE_DATA

CLR C
MOV A,R0
SUBB A,R1
LCALL WRITE_HEX





LCALL WAIT_KEY
CLR LED
MOV A,#5
LCALL DELAY_100MS
SETB LED



LCALL LCD_CLR           ; mnozenie
MOV A,RO
LCALL WRITE_HEX
MOV A,#'*'
LCALL WRITE_DATA
MOV B,R1
MOV A,R1
LCALL WRITE_HEX
MOV A,#'='
LCALL WRITE_DATA
MOV A,R0
MUL AB







ACALL WRITE_BCD



MOV A,#0C0H      ; dzielenie
LCALL WRITE_INSTR
MOV A,RO
LCALL WRITE_HEX
MOV A,#':'
LCALL WRITE_DATA
MOV A,R1
MOV B,R1
LCALL WRITE_HEX
MOV A,#'='
LCALL WRITE_DATA
MOV A,R0


DIV AB

ACALL WRITE_BCD













LCALL WAIT_KEY








LJMP LOOP
END


WRITE_BCD:

MOV B,#10
DIV AB
SWAP A
ADD A,B
LCALL WRITE_HEX

RET