10 REM BASIC program protector
   20 REM (C) 1996 Jon Ripley
   30 REM This program is NOT PD
   40 REM Please DO NOT ALTER this program
   50 DEFFNS="BasProt"
   60 MODE 7
   70 DEFPROCcentre(A$,Y):PRINTTAB((40-LENA$)/2,Y)A$;:ENDPROC
   80 FORY=1TO2:PROCcentre(CHR$141+CHR$(128+Y)+"BASIC Program Protector  ",Y):PROCcentre(CHR$141+CHR$(127+2*Y)+"(C) Jon Ripley 1996  ",22+Y):NEXT
   90 VDU28,0,21,39,4
  100 INPUT"Address of program:&"a$
  110 A%=EVAL("&"+a$)
  120 REPEAT
  130 INPUT"(Un)Protect? (U/P):"a$
  140 IFa$="U"ORa$="u"p$="un":P%=FALSE
  150 IFa$="P"ORa$="p"p$="":P%=TRUE
  160 UNTILINSTR("PpUu",a$)
  170 REPEAT
  180 X%=A%?1
  190 IF?A%=13ANDX%=&FFA%=-1
  200 IF?A%=13A%=A%+3
  210 IF?A%=&F4 AND(A%?1=91ORA%?1=21) A%?1=-(21*P%)-(91*NOTP%)
  220 IF?A%=&F4 AND(A%?1=93ORA%?1=6) A%?1=-(6*P%)-(93*NOTP%)
  230 A%=A%+1
  240 UNTILA%=0
  250 PRINT"Program ";p$;"protected."
  260 PAGE=EVAL("&"+a$)
  270 END