10 CLS:CLEAR:DIM D$(20):PRINT"Press 'L'ock or 'U'nlock or 'Q'uit"
   20 A$=GET$
   30 IF A$="Q"THEN END
   40 IF A$="L"THEN L=1:GOTO70
   50 IF A$="U"THEN L=0:GOTO70
   60 GOTO20
   70 CLS:OSCLI("DIR $"):OSCLI("."):INPUT"Enter Directory Name (RETURN=$)."A$:IF A$="" THEN A$="$":OSCLI("DIR "+A$):CLS:*.
   80 X=0:Y=VPOS:FOR K=1TO20:PRINTTAB(X,Y+1);STRING$(39," "):INPUTTAB(X,Y+1)"Filename (RETURN ENDS) : "D$(K):PRINTTAB(X,Y+1);STRING$(20," ")
   90 IF D$(K)=""THEN GOTO110
  100 NEXT
  110 IF L=0THEN GOTO130
  120 FOR J=1TOK-1:OSCLI("ACCESS "+D$(J)+" WRL"):NEXT:CLS:OSCLI("."):VDU7:A$=GET$:RUN
  130 FOR J=1TOK-1:OSCLI("ACCESS "+D$(J)+" WR"):NEXT:CLS:OSCLI("."):VDU7:A$=GET$:RUN