LEVEL 2:
V-MAX! uses only two density levels in its disk format. Instead
of the two normal density levels used for tracks 25 - 40, the
density level for tracks 18 - 24 is substituted. To copy the
disk properly (excluding track 20), you must use a copier
capable of detecting and reproducing these abnormal densities.
The quality of the copy is very important and should be made on
a drive that is in excellent condition. Correct drive speed is
of the utmost importance!
LEVEL 3:
Some V-MAX! titles require minor changes to a sector or two to
disable a third level of protection that looks for a hard-to-
copy byte sequence on a track. Finding these little routines is
actually the hardest part of making a backup copy of a V-MAX!
protected program. If you don't have a modified 1541 DOS KERNAL
that can trap this protection code (it executes in the command
buffer at $0200), you have little hope of finding and breaking
these routines. Because of this, we'll have to give you these
modifications without further explanation.
The following pages contain specific instructions for making
functional backups of three V-MAX!ed titles: Xevious, Into The
Eagle's Nest, and Paperboy.
* V-MAX! V2 is a whole new ball game, and requires 8K of drive
RAM to duplicate. Special copier routines must be written for these
protection schemes. Also, for your information, we have spoken to
several software publishers about V-MAX!, and their programs using
it. They claim that V-MAX! is NOT a protection scheme, but a fast
loader system only. We are skeptical.
< < < MINDSCAPE: INTO THE EAGLE'S NEST > > >
The entire protection removal process will take place in the
drive. We are going to let the protected code on track 20 load into
the drive and then re-write it to some empty directory sectors. We
will then modify the code that reads track 20 so that it instead
loads our newly-filled sectors.
Prepare a work copy of EAGLE'S NEST using the MAX Copier on your
utility disk, and then load the $1000 monitor. Insert your original
EAGLE'S NEST, initialize the drive (~I) and enter the drive-mon.
We'll be using the 1541/71's job queue to do a lot of the work for
us.
Read T/S $12/$0D into buffer $0700 by entering:
K.J. REVEALED TRILOGY PAGE [135] (C)1990 K.J.P.B.
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