The first real Demo cartridge for the VCS.
The story of the DemoAt the beginning of 2004 I received an
invitation to present my selfmade games and special editions at the austrian
arts festival Steirisc[:her:]bst
I really liked the idea of presenting my games as art and decided to create
something special for the presentation. As there hasn't been a real demo for the VCS by now, I decided to program
different effects and create cartridges from the final version of the demo.
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 DemoThe demo starts in flooding the screen
with water from a valve. After the screen is filled enough, the letters GRAZ appear out of
the water. A jumping ball above the letters bounces them individually into the water.
A vertical bar appears, crosses the former water and in the center a picture fades in.
The vertical bar with the picture starts moving up and down before fading out again.
Afterwards colorful rasterbars - being one of the oldest demoeffects on the C64 -
fill the screen and a logo appears waving horizontally while the colors of the rasterbars
The following picture shows four static frames of the demo. The real demo shows smooth
animations and runs like a movie of course.
After the rasters faded out the demo restarts with an alternative loop. It shows
2004 now and all routines run faster.
Technical informationThe demo is 4 kb (4096 bytes) - including all programcode,
graphics and the music. 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 V1.52 on PC and on the real console of course.
Picture of the cartridges in Graz
Shown are some produced demo cartridges in black cases with color-labels, serialnumbers and
signatures. Laying above these is the official presentation
cartridge which was build from a clear case to show the beautiful inside: the pcb with eprom.
Download of the DemoYou 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
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