Amiga demos

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Amiga demos are demos created for the Commodore Amiga home computer.

A "demo" is a demonstration of the multimedia capabilities of a computer (or more to the point, a demonstration of the skill of the demo's constructors). There was intense rivalry during the 1990s among the best programmers, graphic artists and computer musicians to continually outdo each other's demos. Since the Amiga's hardware was more or less fixed (unlike today's PC industry, where arbitrary combinations of hardware can be put together), there was competition to test the limits of that hardware and perform theoretically "impossible" feats by refactoring the problem at hand. The Amiga was the undisputed leader of mainstream multimedia computing in the late 1980s and early 1990s, though it was soon overtaken by PC architecture.

Some Amiga demos, such as the RSI Megademo, are considered seminal works in the demo field. New Amiga demos are released even today, although the demo scene has firmly moved onto PC hardware. Many Amiga game developers were active in the demo scene.

The demo scene spearheaded development in multimedia programming techniques for the Amiga, such that it was de rigeur for the latest visual tricks, soundtrackers and 3D algorithms from the demo scene to end up being used in computer game development.

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Ripping

The Amiga thrived on public domain, freeware and other not-for-profit development. The architecture provided no substantial mechanism for protecting software from inspection. In order to read the memory one simple performs a hot reset (which preserves the contents of RAM) and then boots to a dedicated floppy disk that can inspect and dump the memory's contents. It was therefore common for developers and hackers to "rip" music, graphics and code and then reuse it in their own productions. This led to intense competition in certain fields, for example, in the development of sound tracking software and Tetris clones, with each group of developers trying to outdo the current state of the art. In fact, some demos even featured their source code as part of the executable to save hackers the trouble of disassembly, though it came strewn with incendiary comments for those who would seek to improve on it.

The doctrine of software patents, copyright and intellectual property was not fully fleshed out at the time of the Amiga's popularity in the late 1980s and early 1990s, and the potential profitability of software was a shadow of what it is today. Consequently, 'ripping' was considered by many, rightly or wrongly, to be fair game. It was not unusual for computer game music and graphic art to appear in demos and music disks (compilations).

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Intros

Smaller demos were often known as intros, and were typically limited to between 4kb and 64kb in size. Intros were originally used as an 'introduction' by a cracker-group on computer games and other software disks cracked for copying and redistribution. Later it developed into a stand-alone artform and many demo/intro groups disassociated themselves from the cracking/copying scene (although many of the major demo groups were still heavily involved in this).

Full demos ranged from under 512KB to several megabytes. There were several thousand demos produced in many languages and many countries, particularly the UK, Germany, and the Nordic countries.

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Demo software

Most demos were custom written in 68000 assembly language, although a few were written in C and other languages. Demos on the Amiga flourished because of the power of the "Copper" Co-processor for synchronising display changes to the vertical beam position on the screen, and the blitter - a chip capable of fast block moving of graphical data from one position on the screen to another.

Eric Schwartz produced a series of animated demos that ran with MoviePlayer, an animation software package similar to Macromedia Flash. The animated demos drew heavily on the whimsy and graphic style of comic strips.

Red Sector Inc (RSI) produced a piece of software called the RSI Demomaker, which allowed users to script their own demos, replete with scrolltext, vectorballs, plasma screens, etc.

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Partial list of Amiga demo groups and demos

Note that these demos are not necessarily the most famous.

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See also

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External links

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