let's look back at the decryption loop at $2355 < D 2355 >
         it's exchanging bytes between $2400 - $2500 and $2600 - $2700.
         Our changed byte (now $54) is at $25C2, -not- at $24C2. It will
         be written to track/sector 1/3 at position $C2 (194 decimal).

      7) Now reset the computer, re-insert the Utility Disk and reload
         the sector editor < LOAD "DISK ?*",8 >. Insert your backup and
         < RUN >. Press the [B] key. Enter 1 < RETURN > and 3 < RETURN >
         to read in track/sector 1/3. Move the cursor to position 194 and
         press the < @ > key. Enter 84 and press < RETURN > . To write
         the modified sector, press < R > and < Y >.

      8) Reset and load the backup.  It DOES load faster than the
         original, doesn't it?




      INTRO : PROTECTION SCHEME TYPE D

      When this protection scheme was first introduced, the copy
      programs available were unable to backup any software that used
      it.

      Most of the nybble utilities on the market today have the
      capability of producing a backup. This scheme is usually referred
      to as the "long sector". The following similarities are
      characteristic of this protection. A nybble utility can back up
      the title, while a fast copier can't. The load is rattle free and
      smooth. An error scan produces a number twenty read error on the
      last sector of any particular track.

      This protection is based on placing an extra sector on any
      chosen track (sometimes more than one track) on the original disk.
      This sector contains one block of valid program data. A non-nybbler
      or file copy utility will not pick up this sector, because it is
      not standard disk format. This will prevent the program from
      operating properly. Our job in each of the following programs will
      be to gather the block of data and place it in the program at the
      proper location.

      The protection itself is nothing more than a special Block Read
      set up to read the non-standard block of data. The routine almost
      always starts out as an encrypted block. This block begins as a
      decryption routine that decrypts one block of data. This, in turn,
      reveals a protection check that does nothing more than read in the
      long sector and place that long sector data directly over itself.
      By doing this, the valid code completely hides the protection
      check itself.

      Recognizing the decryption routine is the best way to locate the
      protection check. Once located, we will start the routine up and

            K.J. REVEALED TRILOGY    PAGE [43]     (C)1990 X.J.P.B.