main1.asm

一些小程序,关于汇编语言中程序的中断的使用,例子中包括字符输出

code segment
    assume cs:code
repeat:
    call decibin
    call crlf
    call binihex
    call crlf
    jmp repeat
    
    mov ax,4c00h
    int 21h
    
binihex proc
    push ax
    push cx
    push dx
    mov cx,4
rotate:
    rol bx,4
    mov al,bl
    and al,0fh
    add al,30h
    cmp al,3ah
    jl printit
    add al,7h
printit:
    mov dl,al
    mov ah,2
    int 21h
    loop rotate
    pop dx
    pop cx
    pop ax
    ret
binihex endp

crlf proc
    push ax
    push dx
    mov dl,0dh
    mov ah,2
    int 21h
    mov dl,0ah
    mov ah,2
    int 21h
    pop dx
    pop ax
    ret
crlf endp

decibin proc
    push ax
    push cx
    push dx
    mov bx,0
newchar:
    mov ah,1
    int 21h
    sub al,30h
    jl exit
    cmp al,9d
    jg exit
    cbw
    xchg ax,bx
    mov cx,10d
    mul cx
    xchg ax,bx
    add bx,ax
    jmp newchar
exit:
    pop dx
    pop cx
    pop ax
    ret
decibin endp

code ends
    end repeat