INTRO : PROTECTION SCHEME TYPE C

         This protection scheme employs the use of a "fat track" to
         prevent the user from making his backup. To make matters worse,
         the fat track is placed on the outer (36-40) tracks.

         Most of the examples covered in this manual work approximately
         the same. The following general loading procedure is taken with
         each.

            1) The boot is loaded and autostarts the program.

            2) A fast loader is set up and activated.

            3) The logo screen is loaded in and activated.

            4) The protection routine is decrypted.

            5) The files pertaining to the program are loaded in. These
               are generally encrypted.
               
            6) The protection is checked, which places a numeric value
               ($FF) in the disk drive's memory.
                  
            7) The value is checked using a memory read.

            8) The value is used as a part of a decryption routine to
               decrypt the main program. Proper decryption takes place
               ONLY if the correct value is returned.

            9) The code then jumps to the start of the program.


         The Activision examples in this manual represent this protection
         scheme in it's most difficult form to un-protect. You'll find this
         same scheme being used by other software publishers, but generally
         not encrypted. They usually check for the value in the same way
         and start the program if found. One example of this will be given,
         and will be unprotected by a different method. Understanding this
         routine is imperative, because this scheme has been improved, and
         will be covered in it's expanded form in updates to this manual.


            K.J. REVEALED TRILOGY    PAGE [21]     (C)1990 K.J.P.B.