AntiISDA Warrior (Commodore VIC-20)

The game concept for AntiISDA Warrior was first developed on the Oric Atmos back in 2003, while resembling one of the demo BASIC programs in the book which came bundled with my Pravetz-8D computer. Because of the simplicity of the gameplay concept and the ease of porting it, I made it possible on wide range of computer and console platforms. Some of the systems on which it is already available, I never had touch or developed for before. One of these systems is the Commodore VIC-20. The VIC-20 or VC20 in Germany, was released in 1980, featuring 1.0227 Mhz 6502A CPU, 5KB RAM, eight character colors and three voices sound. The base model is often called unexpanded VIC. With the usage of VIC-20 emulators on Amiga, the dasm assembler and programming manuals, I was able to do a quick port of the AntiISDA Warrior game for the unexpanded VIC. Because I wanted it to be fast, it was written entirely in assembler. For the ingame graphics, I used own redefined characters, representing the bomb and the enemies, instead of the PETSCII built-in. Later I contacted Anders Carlsson about the music. He created a remix of Your Latest Trick from Dire Straits album Brothers in Arms for the title music. The game have additional music and sound effects, converted from the 6502 Apple II assembler routines I used for other software projects.

The game goal and concept was kept intact on the VIC-20. The story which I made by myself is still the same, only this time you are saving VIC-20 warez, which are going to be removed if you can not hold the attack. The game gets harder and harder with the levels passed, where the invaders go closer and closer to the missile (called pingbomb). The similarity to the game Space Invaders is not only coincidental, but here only the shots are movable, and not the enemies or the initial place for fire. To make the game colorful, I used all the VIC-20 colors from the palette. If the attack is not hold, there is end screen with text and music or if the attackers are successfully removed, there is an outro screen. Full source code for the game is available in the archive. The other platforms for which the game is also available are:

• Amiga - with nice music and sequel as well
• Sinclair ZX Spectrum - written in BASIC
• Oric Atmos - 1K minigame with sequel in 1 KiloByte as well
• Apple II - with high resolution graphics and sprites
• Apple III - with colorful graphics and backgrounds,
• Commodore 64 - written in 6502 assembler
• Coleco Vision - written in C, with color graphics
• IBM-PC - with music and from XT to Core 2 Duo (With WindowsXP) compatibility
• Dragon 32 - written in Dragon BASIC
• Game Boy (Classic) - made with snowy Christmas theme
• Sega Master System - featuring melodic Amiga music
• Game Boy Advanced - the SMS version under emulation

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