ϰ3.15
DATA  SEGMENT
      BUF  DB  20H DUP (?)
      CNT  DB  ?
DATA  ENDS
CODE  SEGMENT
      ASSUME  CSCODEDSDATA
STARTMOV  AXDATA
      MOV  DSAX
      LEA  SIBUF 
      MOV  DL0 					
NEXT1MOV  AH01H				
       INT   21H					
       MOV  [SI]AL 				
       INC   SI						
       CMP  AL0DH					
       JZ    EXIT          			
       CMP  AL30H                 	
       JGE  NEXT					 
       INC  DL						
       JMP  NEXT1					
NEXTCMP  AL39H 				
       JBE  NEXT1					 
       INC  DL						
       JMP  NEXT1					
EXIT MOV  CNTDL				
       MOV  AH4CH 				
       INT  21H
CODE  ENDS
       END  START
