The timing of the Amiga’s 30th Anniversary yesterday was fortuitous, as I’ve been planning a series of somewhat reflective essays relating to computer culture as it affected me in the late 80s through 90s. You can consider these a kind of expansion around some of the thoughts touched on in the earlier essay.
This first essay is going to talk about another aspect of computer culture which was drawn to the Amiga as a result of its powerful additional chips for display, memory and sound manipulation: the demoscene.
To understand demoscene, you first have to understand the artistic and competitive aspects of the hacking subculture, which date back to the 1950s (in computer form). Hacking culture is about demonstrating your deep understanding of a complex system – a computer hardware, a mechanical device, or something similar – by making it do something which people less skilled in the art might think impossible, or which it was never designed to do. In the context of computers, it really emerged from talented students trying to get the limited computers of the 1950s (and later) to perform useful or interesting tasks – hacking is nothing without working against strict limitations. (The modern media concept of “hacking” meaning “to compromise the security of a system” is a derivative of one kind of hacking here, applying your knowledge of computer systems to penetrate supposedly impenetrable security, but the actual term is not so limited to purely destructive use.) Hacking, by its very nature, combines both aesthetic and technical aspects – even the earliest hacks included making a mainframe computer play musical pieces (which it was never designed for at all). *
By the late 1970s, some hackers had been incensed by attempts by early games companies to limit copying of their software via various techniques. (A common belief of hackers is that attempts to restrict information, including software, is an offence to society.) They started working to “crack” the software protection, by analogy with cracking a safe, and releasing “free”, “cracked” copies of the software by other routes. Of course, being hackers, there wasn’t any point to doing this if no-one could tell who had been smart enough to crack the security. The cracked software was therefore usually modified to display a small tag at the start, letting you know who was responsible.
Displaying a small tag isn’t very fun, though, so slowly, different hackers started working to produce more impressive pieces of artwork, or animations as their added intros.
By the mid 80s, these intros had become a separate thing to the cracked software itself. The demoscene had emerged, devoted purely to the creation of more impressive artistic displays, limited by the limited computing and storage available at the time. (Some particular aspects of demoscene place additional limits on themselves – the 64k intro scene, for example, consciously limit themselves to only 64 kilobytes of space.)
Given the opportunity to use the Amiga’s additional resources, the demoscene flourished on the platform, helped mostly by the memory management chip called Angus. As well as controlling access to memory itself, Angus had two features that were critical to impressive video effects – a blitter and a copper. The blitter was a specialised unit designed to perform very rapid operations on rectangular sections of memory – including the display, as that must be represented in memory before being sent to a screen. Most trivially, it could copy one rectangular section to another rectangular section (duplicating an area of a display, for example), but it could also be made to combine multiple areas into a single result (for example, using one section as a “mask” to display only certain parts of a second rectangle). The copper, or co-processor, was a simple, but fast, system which could change various settings of the display in synchrony with the video display. The classic use of the copper was to change colours in the display as it was being drawn, creating a “horizontal striping” effect known as “raster bars”. However, it could change practically any aspect of the display configuration during the display process, including the actual resolution – you could have two parts of the screen using entirely different resolutions, at the same time, with the copper switching between them appropriately.
By creative use of the blitter and copper, combined with the CPU itself, and tracker music for high quality audio in a small space, demoscene could accomplish impressive things on the Amiga. Some examples of the height of the art are: Incision (a 64k intro) and TBL’s TINT (note that both of these were generated, in real time, on hardware a thousand times slower than a modern computer).
Many demoscene artists crossed over with the computer games industry as well, and many computer games showed the influence of their more flashy visual effects. [More recently, the programmer of Angry Birds is an old demoscener, and noted that his experience in doing impressive things with limited hardware was pivotal in making the game work on the small capabilities of a mobile phone.] The modern FPS, written entirely in 96kb, .kkrieger, is a stunning example of what demoscene techniques can bring to games development.
Demoscene is still going strong, although the limitations are now mostly self-imposed, as modern computers are far too powerful to provide an interesting restriction by themselves. An example of the current cream of the crop is in this YouTube playlist, but the scene itself mostly accessible via http://www.demoscene.info/the-demoscene/
* For more information on early hacker culture, the most accessible reference is still Steven Levy’s “Hackers: Heroes of the Computer Revolution”, ISBN 0-385-19195-2. A copyright-free copy of the first two chapters is available via Project Gutenberg.