10 DEFFNucase(lcase$)
   20 REM Returns a string
   30 REM ASCii values of a,z are 97,122
   40 FORX%=1TOLEN(lcase$)
   50 IFASC(MID$(lcase$,X%,1))>96 AND ASC(MID$(lcase$,X%,1))<123 THENlcase$=LEFT$(lcase$,X%-1)+CHR$(ASC(MID$(lcase$,X%,1))AND&DF)+RIGHT$(lcase$,LEN(lcase$)-X%)
   60 NEXT
   70 =lcase$
   80 :
   90 DEFFNgetline(length%)
  100 REM Returns a string
  110 DIM line% length%
  120 DIM block% &5
  130 P%=block%
  140 [OPT2:EQUBline% MOD256:EQUBline% DIV256:EQUBlength%:EQUB32:EQUB126:]
  150 A%=0:X%=block% MOD256:Y%=block% DIV256:CALLoswd
  160 =$line%
  170 :
  180 DEFFNgotbadchr(name$,invalid$)
  190 REM Returns "FALSE" if all the letters are OK
  200 line%=0
  210 FORX%=1TOLEN(invalid$)
  220 line%=line% OR INSTR(name$,MID$(invalid$,X%,1))
  230 NEXT
  240 =line%