TUTORIAL  "HEXING 101" -PART 1
Thanks to Keith, I'll pass on what he and others have taught
me, I hope.  First, my objectives:
1. START FROM SCRATCH - that's where I was. Zero knowledge.
2. Hexidecimal thinking, and how to use debug/PCTools
3. An easy, "starter" hex job for the beginner.
4. A more involved hex job.
5. A discussion of the .SPC file and what's where.
6. A discussion of the .INT file.
7. A discussion of the BGERMSTR.PAC and BAMERSTR.PAC files,
   and how to customize them.
8. Methods of painless plane swapping.
9. More advanced hex techniques, and several methods of
   "discovering" new things.  Use of "Rosetta Stones".
Some of you are way beyond these initial lessons, but bear
with me-it will get better.
WHAT YOU WILL NEED:  You will need a) a limited knowledge of
DOS (copy command, cd, how to move from directory to
directory, filenames and extensions etc) b) a hex editor.  I
cannot imagine doing this with debug only.  I strongly
recommend PCTools V.6, but any hex editor that will allow you
to "look" inside the file at the hexidecimal values will do.
NOTICE: I don't know it all....I am getting good at hexing,
but when it comes to DOS in general, and DEBUG, and
computers, I am not so swift.  I will answer questions as
best I can, but may need to defer to the real experts!
1. "Hexing" or "doing a patch" refers to changing values
inside a file to make the program act differently.  The .SPC
files, located in the SWOTL\AC subdirectory, contain the info
about each plane in the game.  Change these files, and you
can change the plane.  For example, there is a file called
P51D.SPC and another called P51B.SPC.  These contain the info
that make these planes unique.  Each plane in the stock game
has it's own .SPC file.  The very first step in hexing is to
make a backup copy of ALL of these .SPC files.  Do this with
the DOS COPY command, ie COPY P51D.SPC P51D.BAK  or, from the
C> prompt,  COPY C:\SWOTL\AC\P51D.SPC C:\SWOTL\AC\P51B.BAK
This makes a duplicate copy of your P51D.SPC file under a
different name.  You can use any new name you want, but by
using .BAK for all your backups it will help you stay
organized.  Why back them all up?  Because after you change
the .SPC file all around while experimenting, you can undo
any damage simply by typing COPY P51D.BAK P51D.SPC  -this
reinstates the original file from the backup, and all changes
are gone.  No matter what you do, you are safe as long as you
have the .BAK file, so you can return to normal.  (at the
very worst, you could find the P51D.SPC file on the original
game disks and copy it in).  So this gives you the "freedom"
to experiment - any goofs, and just copy the .BAK file back
into the .SPC file.  Your plane is "normal" again.  Any
quesions? Please ask!  Next lesson - DEBUG.COM and
Hexidecimal math.