在大学里，我被分配了以下任务：
将两个文本文件的内容逐个字符地进行比较。只将第一个文件中的字符及其在文件中的位置号与第二个文件中的相应字符不匹配的字符写入新的文本文件。使用TASM汇编程序。
好吧，我写了程序，用Turbo汇编器运行，但没有任何东西被写入output.txt文件。所有文件都在同一个目录下。
file1.txt的内容是abobabiba1，file2.txt的内容是abobapipa1。
从理论上讲，应该将这样的内容写入文件：

5 7

bb

.model large
.stack 1000h
.data
    infile1 db "file1.txt", 0
    infile2 db "file2.txt", 0
    outfile db "output.txt", 0
    buffer1 db 1000h dup(?)
    buffer2 db 1000h dup(?)
    outfile_char db 0
    position db 0
    end_of_file db 0
.code
main proc
    ; open the first input file
    mov ah, 3dh
    mov al, 0
    lea dx, infile1
    int 21h
    mov bx, ax ; bx contains the first file descriptor

    ; open second input file
    mov ah, 3dh
    mov al, 0
    lea dx, infile2
    int 21h
    mov cx, ax ; cx contains the second file descriptor

    ; create output file
    mov ah, 3ch
    mov al, 0
    lea dx, outfile
    int 21h
    mov dx, ax ; dx contains the output file descriptor

    ; read the contents of the first file into buffer1
    mov ah, 3fh
    mov bx, ax
    lea dx, buffer1
    mov cx, 1000h
    int 21h
    ; read the contents of the first file into buffer2
    mov ah, 3fh
    mov bx, cx
    lea dx, buffer2
    mov cx, 1000h
    int 21h

    ; compare the contents of the buffers character by character
    mov si, offset buffer1
    mov di, offset buffer2
    mov cx, 1000h
    mov position, 0
    
loop_start:
    mov al, [si]
    mov bl, [di]
    cmp al, bl
    je skip

    ; set the file pointer to the beginning of the file
    mov ah, 42h
    mov al, 0
    mov bx, dx
    int 21h

    ; write information to the output file
    mov ah, 02h
    mov dl, al
    mov ah, 40h
    mov bx, dx
    mov cx, 1
    mov dx, offset outfile_char
    int 21h
    mov ah, 02h
    mov dl, position
    add dl, '0'
    mov ah, 40h
    mov bx, dx
    mov cx, 1
    mov dx, offset outfile_char
    int 21h
    mov ah, 40h
    mov bx, dx
    mov cx, 1000h
    lea dx, buffer1
    int 21h
    mov ah, 40h
    mov bx, dx
    mov cx, 1000h
    lea dx, buffer2
    int 21h
skip:
    ; increment the position and move on to the next character
    inc si
    inc di
    inc position
    ; check for end of file
    cmp position, 10h
    jne loop_start

    ; close the output file
    mov ah, 3eh
    mov bx,dx
    int 21h

    ; close the second input file
    mov ah, 3eh
    mov bx, cx
    int 21h

    ; close the first input file
    mov ah, 3eh
    mov bx, ax
    int 21h

    ; we complete the program
    mov ah, 4ch
    int 21h

main endp
end main