RetroGames
The demo game for Eurocon 2007. :)



The story of this Demo

After visiting the RetroGames exhibition in Karlsruhe, Germany in 2005 I thought that their logo is eminently suitable for display on the Atari VCS. While developing "Encaved" I started working on a new demo with displaying the RetroGames logo as if it was a slotmachine. I also envisioned an upscrolling graphics display which stretches its top and undermost line to the borders of the screen. While implementing my ideas I decided that the slotmachine part would be more interesting if it can be played as a small game of a bit skill and a lot luck.

What is a Demo?

A demo (abbr. for demonstration) is a non-interactive program which presents audio-visual effects created by hobby programmers to show the abilities of a computer or videogame system and the creativity of the programmer. Demos have got a long tradition on disk-based systems as the C64, Amiga and PC as they were directly created on the machine itself and could be easily and freely exchanged with the copying of floppy disks or through online connections (BBS, Internet).

Cartridge based videogame systems didn't contain keyboards and development tools so their games had to be created on dedicated development systems. The cartridges had to be created and, due to the high production costs, had to be sold.

The effects of the Demo

The demo starts with the upscroller part and shows the graphics while stretching them at the borders. The fire button of the left joystick can be pushed at any time to freeze the upscroller.


After the graphics scrolled through the demo switches over to the slotmachine part. You start with 10 credits and the rolling can be started with the fire button as long as you have credits left. The three rolls can be stopped with the joystick directions left, down and right. Three identical symbols award you with 10 credits and the RetroGames logo (Arcade Spear Player) is worth 20 credits. The game either ends when winning 99 credits or losing all of them.


When the reset button is pushed the demo switches back to the upscroller part. This time another objects is moving behind the upscroller and the graphics display is moving up and down the screen.


Afterwards the slotmachine part is shown again and you could play a round if it. If you press the reset button again, the third incarnation of the upscroller part is shown - this time the bars behind the upscroller graphics are expanding to the left and right.

Please note that these pictures show some static frames of the demo. The real demo shows smooth animations and runs like a movie of course.

Technical Information

The demo consists of 4 kb (4096 bytes) of code and data - with the graphics consuming much of that space. The demo is running in PAL mode with constant 312 scanlines. 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 V1.58 on PC and on the real console of course.

Download of the Demo

The demo was first released at the videogame collector's meeting EUROCON in november of 2007. You can download the demo file here and watch it using a VCS emulator. Please notice that you use the emulator and my demo at your own risk, I don't take any responsibilty for problems occuring to your computer when using an emulator.

Production of original Cartridges

As with the other demos I'm releasing this new demonstration on cartridge for play on the real machine, too. The limited production consists of 33 cartridges with color labels, manual with serialnumber and signature, a RetroGames flyer and a plastic bag. These sets were first available at the convention EUROCON 2007 and most of the copies instantly sold there.


Cartridge with manual, RetroGames flyer and bag.


All 33 cartridges in line.

Owners of the Demo Cartridges

# Name Country
01 Simon Quernhorst Germany
02 Chris Keller (RetroGames e.V.) Germany
03 Jörg Lennhof (RetroGames e.V.) Germany
04 Ingo Boyens Germany
05 Marc Oberhäuser Germany
06 Martijn Wenting The Netherlands
07 Mat Allen England
08 Mr. Atari The Netherlands
09 Rob Goorman The Netherlands
10 Pieter Verhallen Belgium
11 Marco Kerstens The Netherlands
12 Cyril Denis France
13 Hakan Kaya The Netherlands
14 Brian Gordon USA
15 Rene Kamerbeek The Netherlands
16 Rob Neitzke USA
17 Michael Weiß Germany
18 Jörg Konzan Germany
19 r_type2600 Austria
20 Kai Darius Kohl USA
21 Carl Howard USA
22 Georg Fuchs Austria
23 Matthias David Germany
24 Gerald Müller-Bruhnke Germany
25 Bonami Spelcomp.museum The Netherlands
26 Gregor Houghton England
27 RetroGames e.V. Germany
28 John Maccallan Germany
29 Jose Artiles USA
30 Andy Ryals England
31 Rick Weis USA
32 Jeff Rothkopf USA
33 Walter Lauer Germany



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