ENTER_NUM EQU 0fH
    LJMP START
    ORG 100H
START:
    LCALL LCD_INIT
    LCALL LCD_CLR

    MOV R1, #30H  ; od tej komorki w pamieci zapisuje liczby
    MOV R2, #0    ;liczba wpisanych danych
    MOV R0, #0    ; temp

    MOV 30H, #50H
    MOV 31H, #4CH
SIGNS_INPUT:
    LCALL LCD_CLR
    MOV A, 30H
    LCALL WRITE_DATA

    CJNE R2, #1, SIGNS_SHOWN
    MOV A, 31H
    LCALL WRITE_DATA

SIGNS_SHOWN:
    LCALL WAIT_KEY

    CJNE A, #0cH, OPTION1
    ; A == c == strzalka w gore
    MOV A, @R1   ; w A stary znak
    INC A

    CJNE A, #5BH, UP_GOOD
    MOV A, #41H

UP_GOOD:
    MOV @R1, A
    SJMP SIGNS_INPUT

OPTION1:
    CJNE A, #0dH, OPTION2
    ; A == d == strzalka w dol
    MOV A, @R1  ; w A stary znak
    DEC A

    CJNE A, #40H, DOWN_GOOD
    MOV A, #5AH

DOWN_GOOD:
    MOV @R1, A
    SJMP SIGNS_INPUT

OPTION2:
    CJNE A, #0fH, WRONG_INPUT
    ; A == f == enter == zapamietaj
    INC R1
    INC R2

    ;zobacz czy sa juz dwa znaki
    CJNE R2, #2, SIGNS_INPUT
    SJMP NUMBERS_INPUT

WRONG_INPUT:
    SJMP SIGNS_INPUT

NUMBERS_INPUT:
    LCALL WAIT_KEY
    MOV R0, A
    CLR C
    SUBB A, #ENTER_NUM
    JZ DATA_DONE

    ; correct input
    MOV A, R0
    ADD A,#30H
    LCALL WRITE_DATA

    MOV @R1, 00H
    INC R1
    INC R2
    SJMP NUMBERS_INPUT


SHORT_WRONG:
    LJMP WRONG
DATA_DONE:
    LCALL LCD_CLR
    CJNE R2, #28, SHORT_WRONG

    ;liczba sie zgadza
    MOV R1, #4CH
    MOV R0, #30H
    MOV R3, #2

MOVING_LETTERS:
    MOV A, @R0
    CLR C
    SUBB A, #37H
    MOV B, #10
    DIV AB
    JZ DIV0
    MOV @R1, A
    INC R1
    INC R2
DIV0:
    MOV @R1, B
    INC R1
    INC R0
    DJNZ R3, MOVING_LETTERS


    MOV @R1, 32H
    INC R1
    MOV @R1, 33H

    ; zamieniono 4 znaki, teraz dzielimy
    MOV R1, #34H ; nowy poczatkowy
    MOV R0, #30H    ;tam bedziemy zapisywac bcd

    MOV 30H, #0
    MOV 31H, #0
    MOV A, #0
CALC:
    ADD A, @R1
    INC R1
    MOV 30H, A

    LCALL BCD_HEX
    MOV B, #97
    LCALL DIV_2_1
    ; podzielono przez 97
    PUSH ACC
    DEC R2
    MOV A, R2
    JZ CHECK

    POP ACC

    MOV B, #10
    DIV AB

    JZ LESS100
    MOV 31H, A
LESS100:
    MOV A, B
    SWAP A

    SJMP CALC

CHECK:
    POP ACC
    DJNZ ACC, WRONG

    MOV A, #44H
    LCALL WRITE_DATA

    MOV A, #4FH
    LCALL WRITE_DATA

    MOV A, #42H
    LCALL WRITE_DATA

    MOV A, #52H
    LCALL WRITE_DATA

    MOV A, #59H
    LCALL WRITE_DATA

    MOV A, #20H
    LCALL WRITE_DATA

    MOV A, #49H
    LCALL WRITE_DATA

    MOV A, #42H
    LCALL WRITE_DATA

    MOV A, #41H
    LCALL WRITE_DATA

    MOV A, #4EH
    LCALL WRITE_DATA

    SJMP $

WRONG:
    MOV A, #5AH
    LCALL WRITE_DATA

    MOV A, #4CH
    LCALL WRITE_DATA

    MOV A, #59H
    LCALL WRITE_DATA

    MOV A, #20H
    LCALL WRITE_DATA

    MOV A, #49H
    LCALL WRITE_DATA

    MOV A, #42H
    LCALL WRITE_DATA

    MOV A, #41H
    LCALL WRITE_DATA

    MOV A, #4EH
    LCALL WRITE_DATA

    SJMP $
    NOP