dseg segment
	enter	db	0dh,0ah,'$'
	space	db	20h,20h,'$'
 dseg ends

  prognam segment
  main proc far
	assume cs:prognam,ds:dseg
  start:
  	push ds
  	sub ax,ax
  	push ax
	mov ax,dseg
	mov ds,ax

 INPUT:
	mov ah,01h
	int 21h
  	mov ch,2
  	mov bh,al	;to save al
 ;回車換行
	mov dx, offset enter
	mov ah,09h
	int 21h
 ;顯示字符
	mov dl,bh
	mov ah,02h
	int 21h
 ;兩個空格
	mov dx, offset space
	mov ah,09h
	int 21h
  rotate:
  	mov cl,4
  	rol bh,cl
  	mov bl,bh
  	and bl,0fh
  	add bl,30h
  	cmp bl,3ah
  	jl printit
  	add bl,7h
  printit:
  	mov dl,bl
  	mov ah,2
  	int 21h
  	dec ch
  	jnz rotate
  PAUSE:
  	mov ah,07H
  	int 21H
  	mov ax,4c00h
	int 21h
  main endp
  prognam ends
  end