:000E 12 0D
         :0004 80
         
      Disassemble the code at $0700 (D 0700). The first thing the code
      does is move the drive read/write head forward two tracks to track
      20. It then initializes a set of pointers to start the load process
      at buffer $0300 and starts reading bytes from the drive. There are
      no sync marks on the track: the routine reads until it finds a GCR
      byte with the value $5A, of which there is a long series. When the
      $5A byte sequence ends, the code reads and EOR's each successive
      pair of bytes together and stores the result byte to buffers 
      $0300 - $06FF. This produces the custom fast loader code.
      
      You can now understand how a normal nybbler is dead in the water
      if it can't reproduce this track. But we can trap the code easily.
      Bypass the JMP instruction at $0797 by entering:
         
         ]A 078E LDA #$01
         ], 0790 JMP $F969

      This will return control to the drive-mon when the code has
      finished execution. To execute it, enter

         :0004 E0

      When the monitor returns you will be able to look at V-MAX! in all
      its glory. We first must make a minor modification to the code in
      case your work copy is not perfect. There is a sector checksum
      verification routine at $03F3 that will fail if the sector checksum
      is not zero. This can be defeated by entering:

         :03F5 A9 00

      Now we need to re-write the loader code at $0700. Start with a
      fresh copy by re-loading T/S $12/$0D like we did above.
      Directory sectors $04, $07, $OA, and $0C will contain the code
      from $0300 - $06FF. Beginning at $0700, re-write the drive code as
      follows:

        0700    SEI         ;disable interrupts
        0701    LDX #$0D
        0703    LDA $071A,X ;store read data to job queue
        0706    STA $00,X
        0708    DEX
        0709    BPL $0703
        070B    CLI
        070C    LDA $00     ;wait for read to complete
        070E    ORA $01

            K.J. REVEALED TRILOGY    PAGE [136]    (C)1990 K.J.P.B.