dec-hex.asm

一些汇编实验程序

;键盘输入十进制数到16进制数的转换，使用字符串输入输出方式

stack segment stack 
 dw 100 dup(?)
stack ends

data segment
 buff1 db 10,?,10 dup(?)
 buff2 db 10,?,10 dup(?)
 str db "input a data string$"
 crlf db 0dh,0ah,'$'
  mesg1 db "Press y to continue...$"
data ends

code segment
 assume cs:code,ds:data,ss:stack
 main proc far
  mov ax,data
  mov ds,ax
 begin: 
  lea dx,crlf
  mov ah,9
  int 21h

  mov ah,9
  lea dx,str
  int 21h
  mov ah,9
  lea dx,crlf
  int 21h
  mov ah,0ah
  lea dx,buff1
  int 21h
  call buff1_bx
  
  lea dx,crlf
  mov ah,9
  int 21h
  call bx_buff2

  lea dx,mesg1
  mov ah,9
  int 21h

 mov ah,1
  int 21h
 cmp al,'y'
 jz begin
  mov ah,4ch
  int 21h
 main endp

 buff1_bx proc
  mov cl,buff1+1
  xor ah,ah
  lea si,buff1+2
  mov bx,0
 L:
   mov al,[si]
   sub al,30h
   jl exit
   cmp al,9d
   jg exit
   cbw
   xchg ax,bx
   mov dx,10d
   mul dx
   xchg ax,bx
   add bx,ax
   inc si
   loop L
   exit : ret
buff1_bx endp
bx_buff2 proc
  mov ax,bx
  mov dx,0
  lea si,buff2+2
  mov cx,16*16*16
  div cx
  add al,30h
  cmp al,3ah
  jl xx1
  add al,7
  xx1:mov byte ptr [si],al  
  inc si
  mov ax,dx
  mov dx,0  ;因为是无符号数，因此不能进行符号扩展
  mov cx,16*16
  div cx
  add al,30h
cmp al,3ah
  jl xx2
  add al,7
  xx2:
  mov byte ptr [si],al
  inc si
  mov ax,dx
  mov cl,16
  div cl
  add al,30h
cmp al,3ah
  jl xx3
  add al,7
  xx3:
  mov byte ptr [si],al
  inc si
  mov al,ah
  mov ah,0   ;因为是无符号数，因此不能进行符号扩展
  mov cx,1
  div cl
  add al,30h      
  cmp al,3ah
  jl xx4
  add al,7
  xx4:mov byte ptr [si],al   
  inc si
  mov byte ptr [si],'$'
  mov ah,9     
  lea dx,buff2+2  
  int 21h
 
  lea dx,crlf
  mov ah,9
  int 21h
ret
bx_buff2 endp
 code ends
end main