16位汇编 and和or实现大小写转换

and和or实现大小写转换

assume cs:code, ds:data  
  
data segment  
    db 'test'  
    db 'UPDATA'  
data ends  
  
code segment  
      
start:  
    mov ax,data  
    mov ds,ax  
      
    mov bx,0  
    mov cx,4  
      
    s:                  ;将test转换成大写TEST  
      mov al,ds:[bx]   
      and al,11011111b  ;dfh  
      mov ds:[bx],al  
      inc bx  
    loop s  
      
    mov bx,4  
    mov cx,6  
  
    s0:         ;将UPDATA转换小写的Test  
      mov al,ds:[bx]  
      or al, 20h      ;00100000b  
      mov ds:[bx],al  
      inc bx  
    loop s0  
  
    mov ax,4c00h  
    int 21h  
  
code ends  
  
end start  
  
end

assume cs:code, ds:data

data segment

db 'test'

db 'UPDATA'

data ends

code segment

start:

mov ax,data

mov ds,ax

mov bx,0

mov cx,4

s: ;将test转换成大写TEST

mov al,ds:[bx]

and al,11011111b ;dfh

mov ds:[bx],al

inc bx

loop s

mov bx,4

mov cx,6

s0: ;将UPDATA转换小写的Test

mov al,ds:[bx]

or al, 20h ;00100000b

mov ds:[bx],al

inc bx

loop s0

mov ax,4c00h

int 21h

code ends

end start

end

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