struc FileCharTable
 fctLength      dw ?    ; Byte size of structure, excl. this field,
                        ;   and array of characters
                db ?    ; ?
 fctFirst       db ?    ; Lowest permissible character value
 fctLast        db ?    ; Highest permissible character value
                db ?    ; ?
 fctExcludeFirst db ?   ; First in range of excluded characters
 fctExcludeLast db ?    ; Last in range of excluded characters
                db ?    ; ?
 fctIllegals    db ?    ; No. of characters in array
                        ; Start of array of illegal characters (terminators)
ends

label FileNameTerminators byte
; Invalid in filename or file extension (defaults)
  db 00h,01h,02h,03h,04h,05h,06h,07h    ; ASCII 0..31
  db 08h,09h,0Ah,0Bh,0Ch,0Dh,0Eh,0Fh    ; incl. tab, LF, CR
  db 11h,11h,12h,13h,14h,15h,16h,17h
  db 18h,19h,1Ah,1Bh,1Ch,1Dh,1Eh,1Fh
  db 7Ch,3Ch,3Eh                        ; '|<>'
  db 3Ah,5Ch,2Eh                        ; ':\.'
  db 22h,2Fh,5Bh,5Dh                    ; '"/[]'
  db 2Bh,3Dh,3Bh,2Ch                    ; '+=;,'
     NUM_FILE_NAME_TERMINATORS = ($ - FileNameTerminators)