btod(5b).asm

用汇编语言编写的数制转换程序

sseg	segment	stack
	db 256 dup (?)
sseg	ends
dseg	segment
outbuf	db 7 dup(?)
dseg	ends
cseg	segment
	assume cs:cseg,ds:dseg,ss:sseg
start:
     mov  ax,dseg
     mov  ds,ax

     mov  ax,123
     mov  bx,offset outbuf
     call btod

     mov  dx,offset outbuf
     mov  ah,9
     int  21h

     mov  ah,4ch
     int  21h
;*************************************
;subroutine:	   btod
;function  :	   change a unsigned binary(16b) to 5bit-decade
;		   end with '$',the decade is in outbuf
;		   outbuf is already in dseg
;entry parameter:  ax=the binary
;		   bx=offset outbuf
;attention:	   the outcome decade has 5 bits!
btod proc
     push  ax
     push  cx
     push  dx
     push  si
     mov   si,5
     mov   cx,10
     mov   byte ptr [bx][si+1],'$'
btod1:
     xor   dx,dx
     div   cx
     add   dl,30h
     dec   si
     mov   [bx][si],dl
     or    si,si
     jnz   btod1
     pop   si
     pop   dx
     pop   cx
     pop   ax
     ret
btod endp
cseg ends
end  start