汇编语言练习7.9

;datasg段的每个单词的前4个单词变成大写

assume cs:codesg,ss:stacksg,ds:datasg

;栈段
stacksg segment
dw 0,0,0,0,0,0,0,0
stacksg ends
;数据段
datasg segment
db '1. display '
db '2. brows '
db '3. replace '
db '4. modify '
datasg ends

;代码段
codesg segment

start:

mov ax, stacksg
mov ss, ax
mov sp, 16

mov ax, datasg
mov ds, ax
mov bx, 0

mov cx, 4

s0:
push cx
mov si, 3

mov cx, 4
s:
mov al, [bx+si]
and al, 11011111b
mov [bx+si], al
inc si
loop s

add bx, 16
pop cx
loop s0

mov ax,4c00h
int 21H

codesg ends
end start