어셈블리 두 자리 숫자 빼기

Question

두 개의 두 자리 숫자 (사용자가 숫자를 입력)를 더하거나 뺄 필요가있는 대표팀을위한 프로젝트가 있습니다. 나는 일을 더했다. 빼기는 십진 자릿수가 정확하지만 한 자릿수 자리에는 홀수 문자를 제공합니다. 내가 사용하는

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:

• TASM과 TLINK
• 86
• 윈도우 XP (가상 박스)

여기에 내가 (결과의 사진) 무슨 뜻입니다

코드 :

.MODEL SMALL 
.STACK 100h 
.DATA 

    startMsg DB 13,10,'1.) Add ',10,'2.) Subtract',10,'3.) Exit',10,10,'Select a function: $' 
    integer1Msg DB 13,10,10,'Enter the first integer: $' 
    integer2Msg DB 13,10,'Enter the second integer: $' 
    errorOccuredMsg DB 13,10,13,10,'An error occured, please try again! $' 

    sumMsg DB 13,10,10,'The sum is: $' 
    subMsg DB 13,10,10,'The differance is: $' 

    gotNum DB 0 
    func DB 0 

.CODE 
start: 
    mov ax,@data 
    mov ds,ax 

    mov gotNum, 0 ; initialize var 

    ;display & get the selection 
    mov ah,09 
    mov dx,OFFSET startMsg 
    int 21h 
    mov ah,01 
    int 21h 

    mov func,al 

    ;check what the selection was 
    cmp func,'1' 
    je additionIntermediate 
    cmp func,'2' 
    je subtractionIntermediate 
    cmp func,'3' 
    je exit 

exit: 
    mov ah,4ch 
    int 21h 

getNum1: 
    ;get the first integer (1st digit) 
    mov ah,09 
    mov dx,OFFSET integer1Msg 
    int 21h 
    mov ah,01 
    int 21h 

    ;check that input is a number 
    cmp al, 30h ;0 (ASCII 48) 
    jl errorIntermediate 
    cmp al, 39h ;9 (ASCII 57) 
    jg errorIntermediate 

    mov bh,al 
    sub bh,30h 

    ;get the first integer (2nd digit) 
    mov ah,01 
    int 21h 

    ;check that input is a number 
    cmp al, 30h ;0 (ASCII 48) 
    jl errorIntermediate 
    cmp al, 39h ;9 (ASCII 57) 
    jg errorIntermediate 

    mov bl,al 
    sub bl,30h 

    jmp getNum2 

additionIntermediate: 
    jmp addition 

subtractionIntermediate: 
    jmp subtraction 

errorIntermediate: 
    jmp errorOccured 

getNum2: 
    ;get the second integer 
    mov ah,09 
    mov dx,OFFSET integer2Msg 
    int 21h 
    mov ah,01 
    int 21h 

    ;check that input is a number 
    cmp al, 30h ;0 (ASCII 48) 
    jl errorOccured 
    cmp al, 39h ;9 (ASCII 57) 
    jg errorOccured 

    mov ch,al 
    sub ch,30h 

    ;get the second integer 
    mov ah,01 
    int 21h 

    ;check that input is a number 
    cmp al, 30h ;0 (ASCII 48) 
    jl errorOccured 
    cmp al, 39h ;9 (ASCII 57) 
    jg errorOccured 

    mov cl,al 
    sub cl,30h 

    mov gotNum,1 

    cmp func,'1' 
    je addition 
    cmp func,'2' 
    je subtraction 
    cmp func,'3' 
    je errorOccured 

getNumIntermediate: 
    jmp getNum1 

addition: 
    cmp gotNum,0 
    je getNumIntermediate 

    ;add the two numbers and adjust for addition 
    mov ah,0 
    add bx,cx 
    aaa 
    or bx,3030h 

    ;display result 
    mov ah,09 
    mov dx,OFFSET sumMsg 
    int 21h 
    mov dl,bh 
    mov ah,02 
    int 21h 
    mov dl,bl 
    mov ah,02 
    int 21h 

    ;return to beginning 
    jmp start 

errorOccured: 
    lea dx, errorOccuredMsg 
    mov ah,09 
    int 21h 
    jmp start 

subtraction: 
    cmp gotNum,0 
    je getNumIntermediate 

    ;determine which subtraction to use 
    cmp bx,cx 
    jg subtractionPos 
    cmp bx,cx 
    jl subtractionNeg 

subtractionPos: ;integer1 is larger than integer2 
    ;subtract 
    sub bx,cx 
    aas 
    or bx,3030h 

    ;display result 
    mov ah,09 
    mov dx,OFFSET subMsg 
    int 21h 
    mov dl,bh 
    mov ah,02 
    int 21h 
    mov dl,bl 
    mov ah,02 
    int 21h 

    ;return to beginning 
    jmp start 

subtractionNeg: ;integer2 is larger than integer1 
    ;subtract 
    sub cx,bx 
    aas 
    or cx,3030h 

    ;display result 
    mov ah,09 
    mov dx, OFFSET subMsg 
    int 21h 
    mov ah,06 
    mov dl,2dh ;displays the negative sign 
    int 21h 
    mov dl,ch 
    mov ah,02 
    int 21h 
    mov dl,cl 
    mov ah,02 
    int 21h 

    ;return to beginning 
    jmp start 

end start 

나는 매우 신중하기 때문에 어떤 충고라도 잘 될 것입니다.

EDIT

;subtract 
    sub bx,cx  
    mov ch,bh ;store the value of bh 
    xchg bx, ax 
    mov bl,0Ah 
    div bl 
    xchg ah, al 
    xchg ax, bx 
    mov bh,ch ;restore the value of bh 
    or bx,3030h 

Answer 1

;subtract 
sub bx,cx 
aas 
or bx,3030h 

AAS 명령 감산 후 알 조정 수단. BX이 아니라 AL을 조정합니다. BX을 사용하려면 다음 코드를 사용하십시오.

sub bx, cx 
xchg bx, ax 
    mov bl, 0x0A 
    div bl 
    or ax, 0x3030 
xchg ah, al 
xchg ax, bx