The official convention demo.

The story of the Demo

Eurocon is the european convention for classic videogame collectors. After 2004's show in Scheveningen/NL some friends decided to organize the Eurocon 2005 meeting in Bochum, Germany. To contribute to the event I decided to create an official convention demonstration as cartridge for the VCS system.

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.

And producing and selling something unplayable for a game system is very ironic, I think. :-)

The effects of the Demo

The demo starts with music and a moving diagonal pattern fading in. Afterwards a logo scrolls left and right through the screen and the pattern changes style and priority over the logo according to the bass of the music. Additionally the whole screen moves vertically up and down.

After some seconds the first part disappears and a 2005 logo is presented. It flashes to the music and after some seconds a band with a Germany scrolltext appears over the logo, moves in all directions and changes colors and priority over the 2005 logo to the bass of the music.

After the 2005 part the demo restarts with the next of the four alternative passes and loops unlimited.

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 - the music being the biggest part using about 2,5 kb and the graphics and coding using the remaining 1,5 kb. 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.

The cartridge presents a hardware novelty on the Atari VCS as it contains a LED which is blinking while the cartridge is running. The assembly of the EPROMs, cartridge boards and LEDs was done by Christian Keller of RetroGames e.V..

The LED is blinking while the demo is running.

Picture of the cartridges in Bochum

33 cartridges of the demo were produced. Only these contain the LED, labels, serialnumber and signature. Serialnumber 01 has got a yellow, #02 a green and the others a red LED.

All 33 cartridges in line.

Download of the Demo

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.

Owners of the demo cartridges

# Name Country
01 Simon Quernhorst Germany
02 Chris Keller Germany
03 Mat Allen England
04 Jörg Lennhof Germany
05 Oliver Ziegler Germany
06 Marc Oberhäuser Germany
07 Michael Braun Germany
08 Sijmen Schouten The Netherlands
09 Jörg Konzan Germany
10 Ingo Boyens Germany
11 Dieter Kosancic Germany
12 Stephan Freundorfer Germany
13 r_type2600 Austria
14 Dieter König Austria
15 Jens Klöpfel Germany
16 Rene Kamerbeek The Netherlands
17 Martin Jobst-Tremel Austria
18 Steffan Ros The Netherlands
19 Rikard Ljungkvist Sweden
20 Marco Kerstens The Netherlands
21 Kai Darius Kohl USA
22 Walter Lauer Germany
23 Sascha Bejer Germany
24 Carl E. Howard USA
25 Steve Rich England
26 Karl Illetschko Austria
27 Jose Artiles USA
28 Rick Weis USA
29 Jeff Rothkopf USA
30 Pepijn Bakker The Netherlands
31 Al Backiel USA
32 Marco Wollstädt Germany
33 Jens Fickermann Germany

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