loop s1 指令对应的机器码为E2F2,
对F2(11110010)求补=10001110=-14,位移量为-14
偏移地址=该指令的下一条指令的地址+位移量
001B-000D=000D
000D为s1的偏移地址,验证成功。
loop s1 指令对应的机器码为E2F0,
对F2(11110000)求补=10010000=-16,位移量为-16
偏移地址=该指令的下一条指令的地址+位移量
0039-0010=0029
0029为s2的偏移地址,验证成功。
cal word ptr ds:[0] 将s1的偏移地址压入栈中
pop ax 把s1的偏移地址出栈,ax=0021
call dword ptr ds:[2] 将s2的段地址和偏移地址分别压入栈中
pop bx,把s2的偏移地址出栈,bc=0026
pop cx,把s2的段地址出栈,cx=076C
结果一致
assume cs:code, ds:data data segment x db 99, 72, 85, 63, 89, 97, 55 len equ $ - x data ends code segment start: mov ax, data mov ds, ax mov di, 0 mov cx,len mov byte ptr ds:[len] ,10 s1: mov al,ds:[di] mov ah,0 div byte ptr ds:[len] call printNumber call printSpace inc di loop s1 mov ah ,4ch int 21h printNumber: mov bx , ax or bl , 30h or bh , 30h mov dl , bl mov ah , 2 int 21h mov dl , bh mov ah , 2 int 21h ret printSpace: mov ah , 2 mov dl , ' ' int 21h ret code ends end start
运行结果:
商为al,余数为ah,把十六进制下的数值,拆分开来,al表示十位,ah表示个位,然后再转化为字符输出
assume cs:code, ds:data data segment str db 'try' len equ $ - str data ends code segment start: mov ax,data mov ds,ax mov ax,0b800h mov es,ax mov cx,len mov si,0 mov bl,2 mov bh,10 mov ax,0a0h mul bh mov bp,ax s1: call printStr loop s1 mov ah ,4ch int 21h printStr: mov al,ds:[si] mov es:[bp],al inc bp mov es:[bp],bl inc si inc bp ret code ends end start
运行结果:
bl的颜色属性为 I R G B | I R G B
assume cs:code, ds:data data segment stu_no db '201983290196' len = $ - stu_no data ends code segment start: mov ax, data mov ds, ax mov bp, 0 mov ax, 0b800h mov es, ax mov si, 1 mov cx, 2080 s1: mov ah, 17h mov es:[si], ah add si, 2 loop s1 mov si, 3840 mov cx, 34 s2: mov al, '-' mov es:[si], al add si, 2 loop s2 mov cx, 12 mov bp, 0 s3: mov al, ds:[bp] mov es:[si], al add si, 2 add bp, 1 loop s3 mov cx, 34 s4: mov al, '-' mov es:[si], al add si, 2 loop s4 mov cx, 12 mov ax, 4c00h int 21h code ends end start