Question

这是一堂课。本实验的目的是让用户输入M / N形式的一小部分，其中M



;       get two numbers from user and divide them

    org     100h


section .data
numOneMsg   db  "Enter first number: ", "$"
numTwoMsg   db  "Enter second number: ", "$"
resultMsg   db  "The answer is: ", "$"
tmp:        dw                  "     "
M:      dw                  "     "
N:      dw                  "     "
section .text
        xor     bx, bx          ; clear out bx
        xor     ax, ax          ; clear out ax

    mov     dx, numOneMsg
    mov     ah, 9
    int     21h

    mov     ah, 1           ; read in char func
    int     21h             ; read in char
    cmp     al, 0Dh         ; did they hit CR?
    je      secondNum       ; get the second number
    sub     al, 48          ; convert to binary
    mov     [M], al

    mov     cx, 4           ; loop 5 times max


firstNum:
        mov     ah, 1           ; read in char func
        int     21h             ; read in char
        cmp     al, 0Dh         ; did they git CR?
        je      preSecNum       ; set up division
        sub     al, 48          ; convert to binary
        mov     [tmp], al       ; store value to temp
        mov     al, 10          ; get ready to multiply to make number
        mov     bl, [M]         ; get ready to multiply to make number
        mul     bl              ; multiply
        add     al, [tmp]       ; add to make new number
        mov     [M], al         ; store value
        loop    firstNum        ; do this over to increase number for input

preSecNum:
        mov     dx, numTwoMsg   ; print message for second number
        mov     ah, 9           ; print func
        int     21h             ; print out

    mov     ah, 1           ; read in char func
    int     21h             ; read in char
    cmp     al, 0Dh         ; did they hit CR?
    je      secondNum
    sub     al, 48          ; convert to binary
    mov     [N], al         ; store value
    mov     cx, 4           ; set up loop counter


secondNum:
        mov     ah, 1           ; get second number
        int     21h             ; read it in
        cmp     al, 0Dh         ; did they hit CR?
        je      preDiv          ; jmp if they hit CR
        sub     al, 48          ; convert to binary
        mov     [tmp], al       ; store to temp
        mov     al, 10          ; get ready to multiply 
        mov     bl, [N]         ; get ready to multiply
        mul     bl              ; multiply to get increase number
        add     al, [tmp]       ; add to get correct inputed number
        mov     [N], al         ; store number
        loop    secondNum       ; loop to get entire number

preDiv:
        mov     dx, resultMsg   ; print result message
        mov     ah, 9           ; print func
        int     21h             ; print it

    mov     dl, 46          ; put in . to print
    mov     ah, 2           ; print func
    int     21h             ; print period

    mov     cx, 10          ; set up loop counter


divide:
        xor     ax, ax          ; clear register
        xor     bx, bx          ; clear register

    mov     al, 10          ; get ready to multiply
    mov     bl, [M]         ; get ready to multiply
    mul     bl              ; multiply, result in al
    mov     bl, [N]         ; get ready to divide
    div     bl              ; divide bl with al

    mov     dl, al          ; store result to dl
    mov     [M], ah         ; store remainder in M to divide again
    add     dl, 48          ; convert back to decimal
    mov     ah, 2           ; print out function
    int     21h             ; print it
    loop    divide          ; loop 10 times

endProgram： mov ax，4C00h;结束dos功能 int 21h;结束计划

我正确使用源索引（si）吗？

0 个答案: