Raster Fahndung
My 3rd Game Development for the Atari 2600.

The Story of Raster Fahndung

While producing the limited edition of A-VCS-tec Challenge I pondered about the next game project and thought that a game for either one or two players simultaneously would be nice. I already programmed some small demo effects - one of them being a rotating chessboard tube. The demo effects form the intro of Raster Fahndung now and the chessboard lead to the idee of searching for small patterns inside a board with a big pattern. I considered if such a game would be possible on the Atari 2600, because the limited RAM of only 128 bytes would have direct influence on the size of the pattern. When the main display routine proved to be possible all the game elements were added aswell as the one or two players option.

The game title itself is a german description of the game's objective: to search for a specific pattern, but notmally it's used by the police. The expression "Rasterfahndung" itself was the german "bad word of the year 1980" and may be translated to "dragnet investigation". As 1980 was about the time of the Atari VCS being strong, I concidered this title being perfect.

The Introduction Sequence

The cartridge starts up with displaying the bouncing game logo and two rotating chessboard tubes.

After some seconds the cartridge displays the copyright information along with a conversion of my "Denker2000" picture which I first drew some years ago on the C64.

The One Player Game

In the intro you can choose to play a one or two players game by either pressing fire of joystick one or joystick two. The one player game starts with a random board and your cursor located in the middle. Above the board is a countdown timer and the player's score is shown below the board.

Pressing the fire button of your joystick shows the pattern which you have to find inside the board.

Releasing the fire button brings you back to the board where you have to search for the pattern. Pressing the fire button at the right position awards you with the remaining time as points and the next level. Pressing the button at a wrong position shows the small pattern again.

The game ends when the time counter runs to 00. To make things a bit more difficult, the time counter runs faster when the small pattern is displayed.

The Two Players Game

If you chose the two players game in the intro, the game starts with two different cursors inside the board and individual scores for each player.

The objective is the same as in the one player game: look at the pattern and search for it inside the game board. Both players can watch the small pattern individually, but remember that the time runs faster when the small pattern is shown.

Releasing the fire button brings you back to the board where you have to search for the pattern. Pressing the fire button at the right position awards the winning player with one point and the game continues with the next level. Pressing the button on a wrong position shows the small pattern again.

The game ends when either the time counter runs to 00 or one of the players manages to reach 9 points. To make things a bit more difficult, the time counter runs faster when the small pattern is displayed. It runs even faster if both players press the fire button at the same time.

The Game Time Modes

You can choose one of the two game modes with the left difficulty switch. The "Easy" setting gives you a fixed time limit per level, starting at 90 and decreasing by 5 per level until a minimum of 20 seconds is reached. All following levels give you 20 seconds time limit.

The "Hard" setting gives you 90 seconds at the beginning of the first level. You start the next level with the remaining time of the previous one. This means that the time is running from 90 to 0 and you can solve as many levels as possible within this time. Solving each level gives you a bonus time of 5 seconds.

General Game Controls

Technical Details

The game is written in 6507 assembly and consists of 4 KB (4096 Bytes) of coding, graphics and sound effects. The VCS only offers 128 bytes of RAM of which 80 Bytes are used for the random playfield alone. The remaining space is needed for the position coordinates of the players, the scores, the timer, the small pattern and some technical information. Creating the excerpt of the small pattern from the random playfield uses a lot of bit shifting due to the complex way the Atari handles its display - every second value is stored with the bits in reversed order for example.

Due to differences between PAL- and NTSC-consoles, the game needs to be adjusted to both TV-standards. The first development version was PAL format (312 scanlines, 50 Hz) and converted to NTSC (262 scanlines, 60 Hz) afterwards.

The development was performed on a Pentium-PC using a normal Text-Pad as editor and DASM V2.12 as compiler. Testing was done using the emulator z26 V1.52 and V1.58.

Download of the Game

You can download the PAL version of the game file here and the NTSC version here. Use a VCS emulator to play the game. Please notice that you use the emulator and my game at your own risk, I don't take any responsibilty for problems occuring to your computer when using an emulator.

Production of Original Cartridges

The game is released as a limited edition of 75 copies first. The limited edition contains these items: PAL/NTSC-cartridge, plastic box, instruction manual, photo print, serialnumber and signature. Every limited edition cartridge contains a switch on the back of the cartridge to choose PAL or NTSC mode.

Besides the limited edition of 75 copies, the unlimited run (normal cartridge and manual only) will supply as many copies as requested. Please order your copy of the unlimited edition game cartridge (PAL or NTSC) with manual directly from this retailer:

Pictures of the Limited Edition

The back of the cart showing the PAL/NTSC-switch.

A complete copy of the limited edition.

All 75 boxes.

Owners of the Limited Edition

# Name Country
01 Simon Quernhorst Germany
02 Christian Keller Germany
03 Marc Oberhäuser Germany
04 Jeff Rothkopf USA
05 Remowilliams USA
06 Rick Weis USA
07 Jose Garcia USA
08 Kai Darius Kohl USA
09 Carl Howard USA
10 r_type2600 Austria
11 Christoph Pistner Germany
12 Mat Allen England
13 Walter Lauer Germany
14 Richard Lecce USA
15 Mike Chassin USA
16 Luke Sandel USA
17 Michael Weiß Germany
18 Cyril Denis France
19 Jörg Lennhof Germany
20 Dieter Kosancic Germany
21 Jose Artiles USA
22 Michael Garber USA
23 Al Backiel USA
24 Leonard Hermann USA
25 Fabian Grossekemper Switzerland
26 Philip Rubin USA
27 Ingo Boyens Germany
28 Michael Tausendpfund Germany
29 Gregor Houghton England
30 Matthias David Germany
31 Ed Mann USA
32 Ryan Hefferan Australia
33 Andy Ryals England
34 Dan Cremins USA
35 Rob Neitzke USA
36 Jerry Greiner USA
37 Syd Bolton Canada
38 Lance Bohy USA
39 Chris Austin USA
40 René Meyer Germany
41 Horst Lienert Germany
42 Jörg Konzan Germany
43 Lori Burgener USA
44 Marco Kerstens The Netherlands
45 Alain Kohn Luxemburg
46 Hartmut Ahl Germany
47 Yannis Pachnis England
48 Mr. Atari The Netherlands
49 SOLD Germany
50 Jim Donahue USA
51 Lars Willemsen Germany
52 Lukas Meller Germany
53 Dan Cage USA
54 Gilles Bordelais Belgium
55 Jörg Müller Germany
56 Computerspielemuseum Berlin Germany
57 Ron Engel USA
58 Christian Gleinser Germany
59 Michael Braun Germany
60 Conny Jungholt Germany
61 Binarium Germany
62 Sascha Hensel Germany
63 Bernd Neikes Germany
64 Arne Israel Germany
65 AntaBaka Germany
66 SOLD Germany
67 Florian Germany
68 Russ Perry jr. USA
69 Holger Meller Germany
70 Oliver Schlesier Germany
71 Ralf Griewel Germany
72 Kevin Roeper Germany
73 Boris Kretzinger Germany
74 Jörg Dröge Germany
75 Tim Benish USA

This game for the Atari 2600 was written in 2006 and is (C) by Simon Quernhorst.
The URL www.quernhorst.de is owned by my brother, who is not to be connected
with the development of this Atari 2600 game, so don't bother him with mails.
Atari is a registered trademark, 2600 and VCS are trademarks of Atari Corporation.

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