Program:     Alien Breed II
Author:      Jimsoft Software (James Vernon)
Version:     2.0
Description: Shoot-'em-up game
Machine:     TI-83
Language:    Z80 Assembly Code
Released:    April 2000
Size:        Program File (required)      - 8176 bytes
             Data File (optional)         - 5333 bytes
             Uncompressed External Levels - 1627 bytes
             Compressed External Levels   - 400-600 bytes


PLEASE NOTE THAT VERSION 2.0 HAS UPDATED DOCUMENTATION!!
I SUGGEST YOU READ IT.


**Version History**

v1.0: (13229 bytes) - August 1999
- First version
- Not too many bugs
- Compatible with: AShell, SOS and the TI-OS

v1.1: (12870 bytes) - September 1999
- Guardians easier on "Easy" & "Medium" difficulty levels
- Now up to 5 bullets can be shot in a row!
- Fixed small bug on Level 7
- Code totally optimised!
- Updated code documentation

v1.2: (8799 bytes) - October 1999
- Saved lots of mem by reducing Mission Information
- Bullets don't go through the Power Domes anymore
- Use Huffman Compression to reduce Level Data to less
  than 3000 bytes!
- No longer compatible with Aurora, if you want an Aurora
  compatible version, just ask me
- Killed counter bug on AShell/SOS fixed
- Now compatible with Ion for the TI-83!
- "Aliens appearing in space for no apparent reason" bug
  seems to be fixed

v1.3: (8806 bytes) - October 1999
- Fixed bug wherein calc would be stuffed up if you got
  a MEMORY or UNDEFINED error in one of the shells
- Slowed down the counter for the destruction sequence a
  bit (it was getting too fast!)
- Changed it so that you start with 10 bullets instead of
  none
- Tried to explain parts of the source better
- Changed the high score display to:
  "High Score: 0 by AAA"

v1.4: (9251 bytes) - November 1999
- Bullet display bug finally fixed!!
- Changed it so [Enter] is used instead of [2nd] in most
  places
- Slowed down destruction sequence counter a bit more
  again
- Bullets move fast regardless of difficulty level (now
  you can't run past your bullets!)
- Source code documented more
- Only 30 aliens can be controlled by the AI at once now
- Can adjust contrast in Pause menu by pressing [+] and
  [-]!
- No longer Ion compatible for the 83 OR 83+ due to there
  being too many problems to overcome with too little time
  to sort them out.. sorry 83+ owners!

v2.0: (13509 bytes) - April 2000
- New main menu
- Supports external levels
- More graphics
- In-game animations
- Two types of aliens
- Intex Network System - buy guns, ammo, key packs, view a
  map of the level, etc.
- Three Different guns, each with differing strengths
- 11 levels
- More weapons
- Level editor
- Now compatible only with SOS to enable users to have
  more external levels on their calc at once


**Features**
- Compatible only with SOS
- 3 Difficulty levels (Easy, Medium, Hard)
- 11 Stages with increasing difficulty
- Artificial Intelligence!
- 3 Queen Aliens
- Make your own levels!


**Included Files**
- ab2.83g        (program file and data file)
- ab2edit.83p    (on-calc level editor)
- readme.txt     (this file)
- editor.txt     (readme file for level editor)
- ab2.z80        (source code for game)
- ab2edit.z80    (source code for on-calc level editor)
- huffman.h      (huffman decompression routine)


**Setup**
  Send the file ab2.83g to your calculator. Run SOS and
select "Alien Breed II v2.0". The game can be played
without the file "AB2DATA" on your calculator but you will
only be able to play external levels.
  PLEASE NOTE: Remember that all external levels and
"AB2DATA" must be loaded on to the calc after the file
"AB2" otherwise the calc will crash due to the way SOS
operates!


**Background**
  You are a marine that has been sent to investigate what
seems to be a derelict space station only to find that it
has been infested with an alien breed.
  Your mission then becomes clear - destroy the space
station by whatever means possible to prevent the
infestation from spreading.
  Armed only with your trusty laser gun, you set off into
the corridors of the Space Station to do battle with these
vile creatures...


**How to Play**
  At the main menu, select to either start a new game, enter
a passcode, play an external level or quit. Note that you
don't have to have the AB2DATA file on your calculator
that contains the data for the main levels - although if
you don't, you can't play the main game, only external
levels. I made it like this so you can have more external
levels on your calc if you wish.
  Your job is to kill the aliens as you proceed further into
the space station. Most deck levels will have a mission that
needs to be completed - for example, on Deck 2 you are
required to blow up the 4 Power Domes. On these levels, once
the mission objectives are obtained a destruction sequence
will be initiated, giving you a limited time to get to the
deck lift. It is important to remember to read the mission
objectives that are shown before each level (on external
levels, the level author is likely to have a readme that
contains mission objectives).
  The Intex Network System can be used to purchase much
needed supplies, as well as different weapons, or also to
look at a map of the current level.
  When you begin, the only way you can view a map of the
level is on an Intex Console. Once you pick up enough
credits, you can purchase a Radar Scanner. This allows you
to view a map of the level no matter where you are. On the
map the walls are shown and you are the flashing dot (note
that this is sometimes hard to see).
  Remember that when the destruction sequence is on, all
Intex Consoles and your Radar Scanner are useless.
  Enjoy the game!!


**External Levels**
  At the present time, there is only one way to make your
own levels - on the calculator. However, there is the
possibility that there may be a level editor on computer in
the future. This will incorporate the Huffman compression
for external levels (levels have to be compressed on the
computer). If you have an external level and you wish to
have it compressed, send the 83p file to me and I will send
it back to you compressed. Uncompressed levels are 1627
bytes in size, while compressed levels are generally around
400-600 bytes.


**Controls**
MAIN MENU:
  [Up]+[Down] - Toggle selected item.
  [2nd] - Select item.
  [Alpha] - Next external level (when selected)

IN-GAME:
  Keypad - Move your marine.
  [2nd] - Shoot. Hold it down to shoot up to 10 bullets in
          a row!
  [Alpha] - Look (Hold this down and when you press the
            keypad keys the marine will not move, only turn
            to face the direction you pressed)
  [Del] - Access Intex Network (must be facing a console)
  [Y=] - Toggle weapon
  [Mode] - In-game menu (Pause).
  [Math] - Teacher key, turns calc off. When you turn
           the calc back on, it's Paused.

PAUSED:
  [Up]+[Down] - Toggle selected item.
  [Enter] - Select item.
  [+] - Increase contrast
  [-] - Decrease contrast

ENTER PASSCODE/NEW HIGH SCORE:
  [Up]+[Down] - Change letter.
  [2nd] - Select letter.

MISSION INFO:
  [Enter] - Continue

SELECT DIFFICULTY:
  [Up]+[Down] - Change selection
  [Enter] - Choose selection

GAME OVER:
  [Enter] - Continue

EXTERNAL LEVEL FINISHED:
  [Enter] - Continue


**What you will see (sprite descriptions)**

  There are many things you will see during your missions
through the space station - here are some descriptions of
everything:

============================================================
          - Floor, you may walk here
        
        
        
        
        
        
        
============================================================
        - Hatchery floor, slimy yet safe to walk on
      
      
       
     
      
       
      
============================================================
      - Space, outside the space station
    
    
    
    
    
    
    
============================================================
      - Deck Lift, your transport down to the next deck!
      
    
    
    
    
      
    
============================================================
  - Key Pass, used to open closed doors but can only
          be used once
     
 
   
     
      

============================================================
         - Ammo Clip, used to restore your ammo, ammo clips
          can be used with any gun
     
    
    
     
      
       
============================================================
  - First Aid, makes you feel better!
      
    
  
  
    
      

============================================================
      - Extra Life, gives you an extra life
      
    
      
    
    
      
    
============================================================
          - 10 Credits, MONEY!, gives you 10 credits
        
  
  
  
  
        
        
============================================================
          - 100 Credits, gives you 100 credits
        
  
      
      
  
        
        
============================================================
        - Door, can be opened with a key pass
      
      
      
      
      
      
      
============================================================
          - One Way Energy Shield, can only be walked
        through the specified way, otherwise you get
        fried!
        
        
      
  
        
============================================================
        - Open Fire Door, will close automatically when
          you walk over it. After that, it can't be opened
          again!
        
        
      
      
      
============================================================
        - Closed Fire Door, can't be opened
    
    
      
      
    
    
      
============================================================
        - Alien, the standard enemy
      
      
  
  
    
    
      
============================================================
        - Worm, a weaker enemy
      
      
      
      
      
      
      
============================================================
      - Air Duct, safe ones will take you straight to
          the end of the level but dangerous ones will
          kill you...
      
      
      
      
    
============================================================
    - Intex Console, use these to log onto the Intex
    network wherein you can purchase needed supplies

    
    


  
============================================================
  - Wall







============================================================
  - Power Dome, you are usually required to shoot
          these
    
    
    
    
      

============================================================
      - Egg, contains a baby alien but these won't hatch
        for a while yet.. the egg is harmless
     
 
   
  
      
    
============================================================


**Notes about playing**
  Be sure to read the Objectives prior to starting each
mission. You must complete the Objectives before the Deck
Lift that leads to the next level will work. In most
cases, you will have a certain amount of time to get to
the deck lift - if you run out of time the Space Station
will explode!
  In the Pause menu, you have the option to continue or
retreat. You may also increase or decrease the contrast.
The game stats are also displayed. If you retreat, the Space
Station will explode and it will be game over.
  If you are having trouble, I can give you assistance.
Feel free to e-mail me and tell me what level you're on
and what the problem is that you are having and I will
help you.


**Future Versions**
  I haven't really got too many ideas for future versions
of Alien Breed II (apart from optimisations). A level editor
for PC is one idea.
  Another possibility is Alien Breed Deathmatch (linkplay).
  Of course, if you have any ideas, please contact me!


**The Source Code**
  I have included the source code to both the game and the
on-calc level editor. The code isn't fully documented like
in past versions but it may still help ASM learners. If you
have a question, contact me!


**Known Bugs**
  None that I know of!! I've fixed all the bugs that I've
seen so if there are bugs that I don't know about please
contact me straight away so that I can try and fix the
bug in any future versions!


**Disclaimer**
  Due to this program being in ASM, it does low level
stuff to your calc, therefore it could make it crash,
but it shouldn't. Just in case, make sure you have a
backup of the contents of your calculator before you
put Alien Breed II on there, and if you do think that
my program has done something to your calc, feel free
to e-mail me at the address below.


SPECIAL THANX TO:
- Jimmy Mardell and Florent Dhordain for the teacher
  key routine and particularly for all the Huffman
  compression stuff which has saved lots of MEM!!
- Ian Graf for the contrast setting tutorial and for some
  code I borrowed from Slopes on searching for the external
  levels
- Hannes Edfeldt for Devpac83
- Bill Nagel for Pic83
- James Matthews for ASMGuru v4.0, the fast (and easy) way
  to learning assembly on the 83!
- Ahmed El-Helw for the fast_vputs idea from ZTetris which
  saved a bit of mem
- Joe Wingbermuehle for the optimisation tips on his
  website and for SOS and for pointing out the bug with
  shells in v1.2!
- Damian Green for his ideas
- Nich Constantinidis for his ideas
- Craig Stonehouse for his ideas
- Assembly-83 Mailing List
- Ticalc for hosting the mailing list
- Everyone who releases their source code: this is the best
  way to learn ASM
- Team 17 for the original Alien Breed games for the Amiga!
- And anyone else I forgot to mention!



  You may add Alien Breed II v2.0 to your webpage, but be
sure to not separate this readme from Alien Breed II!

  The original Alien Breed game was released by Team 17
back in 1991. It had 6 levels and was a hit! In 1992, they
released another version - Alien Breed '92: Special Edition.
This version had 12 levels with lots of new ideas, although
the game play was relatively similar to the first. A few
years later Alien Breed 2 was released. It had more levels,
more breeds of alien (including one's that shoot at the
player), more guns, better graphics but still had the exact
same idea. The latest and probably last 2D version of this
game was Alien Breed: Tower Assault. This game incorporated
the "choose your own adventure" look by making it possible
for the player to choose which paths to take.
  My calculator version, although called Alien Breed II, is
more or less based on Alien Breed '92: Special Edition,
mainly because that was the version I had on my Amiga. This
version is called Alien Breed II because I had already made
a version in TI-BASIC in 1998. I used to love the game and
ever since I bought the TI-83 I wanted to make it.. here it
is! The later the versions get, the more the calculator
version becomes like the computer version.

  If you have any bug reports, comments or suggestions,
or if you wish to port this game to another TI calc,
feel free to e-mail me.

Alien Breed II v2.0
Copyright 1999-2000 Jimsoft Software
Written and Programmed by James Vernon
E-mail: jimbob_v@hotmail.com