Glossary of Demo Terms

Please keep in mind that this document is still growing; as such, there are probably going to be missing definitions, links, or explanations, so be patient. Also, if you have anything to contribute, please do, to trixter@mcs.com.

Demo Types

Demo: A a program that displays a sound, music, and light show, usually in 3D. Demos are created by coders, graphicians, and musicians all in the same demo group.

Mega-Demo: A demo that is very large, with many parts.

Intro: A demo that is small, usually no larger than 64K. Intros usually have no more than 5 effects in them, and are usually used to introduce something new, like a demo competition, a new group, or a BBS.

Texttro: Am intro that is quite small, with lots of text and few effects; usually made for small announcements.

Dentro: An intro whose sole purpose is to offer a preview of an upcoming demo that's not yet finished.

Wedtro: An intro whose sole purpose is to announce the wedding of a demo scene member. (Only one to date is Trixter's WedTro)

Babytro: An intro whose sole purpose is to announce the birth of a demoscene member's child. (Only one to date is Nostalgia's BabyTro)

People involved with Demos

For pictures of your favorite demo people, click here.

Coder: Person who programs the demo. There are usually more than one per demo group, and they usually split the duties: One will package the whole demo, another will do the sound/music routines, and they all usually contribute to the effects.

Graphician: (Also called a graphcs artist) Someone who draws the graphics for a demo. Usually responsible for coming up with a logo as well, and an ending ANSI screen. Click here for an example of some of the fantastic art created by graphicians.

Musician: Person who writes the music. Music is almost always written in a MOD-like format or a variant of it, and is composed in a tracker.

SysOp: The System Operator of the Group's BBS, if they have one. The SysOp is responsible for making the group's latest productions available.

Courier: (Also called a "spreader") A Courier copies (or "spreads") the demo around to other people and other BBS's, so that many people can view the demo. Couriers are usually freelance, but some belong to a group.

Demo Group: A group of Demo coders, graphicians, and musicians organized under one name. Some of the most popular groups are Future Crew, Triton, and Renaissance. The diskmagazine Imphobia regularly reports on the top groups. so look there for the most current statistics.

Sattlelite Crew: A group of Demo coders, graphicians, and musicians that help to complete another demogroup's production without actually belonging to that demogroup. Usually these people are members from a friend demogroup, or independent people.

Scene Member: Anyone who's contributed something to the demo scene.

Demo-related groups

ANSI Groups: Groups of people who draw graphics for BBS's, but the graphics they draw are entirely made up of ASCII and extended ASCII text characters. (This is so the graphics can be displayed in text mode, or conviently transmitted via a BBS while on-line.) ANSI is the term given the standard color and positioning codes that are embedded in pictures to give them color, etc. Recently, ANSI groups have been drawing pictures for demo groups. Click here for an example of ANSI Art.

Music Groups: Groups of people who compose music. 90% of the music composed is tracked with a tracker; the rest is either MIDI or another music format. Probably the most well-known music group is the KLF.

Gatherings:

Demo Competition: A large gathering of people and groups who create or enjoy demos. There are usually competitions for best demo, best music, best graphics, etc. The two biggest competitions are usually Assembly and The Party.

Demo Compo: A slang term for a Demo Competition.

Demo Party: A Demo Competition with less emphasis on competing and more emphasis on having fun (not to say that competitions don't have fun--they do, but Demo Parties are much smaller.)

Demo Scene: The entire organization of all people, groups, and productions associated with demos.

Scene Member: A member of the demo scene.

Magazines and Collections

Disk Mag: An electronic magazine that focuses on the entire demoscene, having articles about creating demos (coding, music etc.), the latest parties (with reports from scene members), interviews with scene members, and typically some 'weird stories'.

MusicDisk: A collection of music from a demo group, or several demo groups. Usually released when the group's musicians produce more music that the entire group produces demos. Music disks are subject to design, just like demos, and usually have graphics or other information with the songs.

Music Pack: A collection of music from a demo group or a lone scenemember that is usually just the music and a player (in other words, no design at all).

Graphics Terms

VGA: Video Graphics Array. The current graphics standard that demos are programmed in. Its default resolutions/colors are 320x200x256 and 640x480x16.

Tweaked Video Modes: video modes that are made possible by "tweaking" (reprogramming) the VGA card's registers. Tweaked video modes have a difficult to work with memory structure, but the advantages outweigh that problem. For instance, tweaked video modes offer the following:

Multiple resolutions, like 320x240 (square aspect ratio) and 360x480 (high resolution) in 256 colors.
Multiple video pages.
Total control over write planes, so that when you write out one pixel, you actually write out four. This is FAST and great for polygon fills (which are crucial to 3D graphics, the cornerstone of demo effects).
The ability to set the display start address anyhere you want. This lets you scroll the screen in any direction smoothly, at the full frame rate.

Mode X: A common tweaked video mode. Mode X is the most common video mode used in demos, with 320x240 resolution, over 3 video pages, and pixels with a square aspect ratio.

Mode Y: A common tweaked video mode. Mode Y has four video pages and a resolution of 320x200.

Demo Elements

Design: In the ever-more competing demo world, design is probably the most important element of a demo. Design is, literally, how the demo is designed. A good design shows the parts of the demo leading into one another smoothly or cleverly, so that the flow of the demo is not interrupted. Design is also responsible for how the graphics elements are arranged.

Examples of *bad* design:

All of the pictures are displayed in the center of the screen with a black background. Boring.
The sections between parts of the demo say things like "Here comes the shadebobs", "Here comes the dot-tunnel", "Here comes the Vector World", etc.
Misspelled text, lots of swearing, gore, etc.

Realtime: The term given to effects that are being calculated by the computer's cpu as you are seeing them (as opposed to pre-calculated, which is considering cheating by some scene members). Real-time effects that look good are the result of well-structured or clever programming.

Effects: A graphical effect that is usually cool to watch. Some older common effects were plasmas, dissolves and fades, and sinuses; many common effects are texture mapping, Gouraud and Phong shading, and motion blur. Many effects can be combined, like a bitmap that both rotates and zooms in and out at the same time. Effects are almost always calculated realtime.

For various examples of real-time effects, click here.

Sound/Music Terms and Formats

Music Module: (also sometimes called a MOD or MOD-like format) A song in one of the formats most used by demoscene musicians. Tracker: A program that allows you to compose music in a MOD-like format or a variant of the MOD format. Trackers have several advantages:

They offer complete control over the music, even as far as editing the exact volume and pitch slide paramters.
They use digitized instruments which are sampled from real instruments. The result is that the instruments are very clear-sounding and realistic. Another advantage of that is that you can digitize your own instruments.
They have enhanced editing capabilities, like easily cutting/copying/pasting tracks.
Because the composer has complete control over the playing parameters as well as the exact instruments used, music files created by trackers sound the same on all platforms (the digital instruments are included as part of the song file).

Because of their pattern-based format, MOD-type music files are fairly easy to program players for. They have some disadvantages, however:

The structure of the music is very rigid--it lends itself to compose music that is 4/4 time only. (Composers have learned tricks around this, however, and managed to do triplets, syncopation, and jazzy rhythms--but it isn't as easy as other methods, like MIDI for instance.)
Most trackers allow for computer keyboard input only; no musical keyboard can be used for input.
Each track can only play one note, so chords must be entered manually on multiple tracks.

Still, the music created can be very stunning.

For some musical examples, click here.

Mixing: A technique to overcome the limitations of PC sound hardware. Normally, PC sound cards can output one or two channels of digitized sound, which isn't very useful if you want to play music with 8 or more channels. Mixing overcomes this limitation by utilizing the power of the computer to mathematically mix all of the channels into only one or two channels inside of the computer. The resulting channel or channels is then output through the sound card. (The number of channels in the output depends on whether the sound card is mono or stereo.) The quality of the output is usually excellent, but can depend on the number of channels being mixed and the speed of the computer. The only drawback to this system is that it steals time away from the CPU.

Gravis Ultrasound: (Also called the GUS) A great sound card at a low price, the Gravis Ultrasound can play up to 32 digital channels at the same time, eliminating the need for mixing. This card has become the standard of the demoscene. (In fact, here's a comparison of its wavetable synthesis against a Sound Blaster for your listening pleasure, in both Microsoft .wav format and Sun/NeXT .au format.) There are three varities: The GUS, GUS MAX, and GUS ACE. The MAX is a normal GUS with cdrom and 16-bit recording facilities; the ACE is a GUS without any recording facilities. The GUS ACE is only $99, which makes it a great way to add wavetable to any existing sound card.

Music file formats

MOD: Amiga Protracker. The most popular music file format in the demo scene. Originating on the Amiga computer, MODs contain up to 4 channels of music. Later PC implementations of the MOD format by Triton introduced 6 or 8 channels.

STM: Scream Tracker. This music format was created by Psi / Future Crew. Very similar to the MOD format, it also contains up to 4 channels.

669: This music format was created by Tran, formerly of Renaissance. It was the first 5+ channel format on the PC; contains 8 channels.

MTM: MultiTracker. A newer format created by StarScream / Renaissance. Supports up to 32 channels.

S3M: Scream Tracker 3.0. A later modification of the STM format. Supports up to 16 channels; the tracker used to create these modules is possibly the best on the scene.

FAR: Farandole Composer. Offers 16 channels.

XM: FastTracker ][ format. Recently introduced, the XM format stands for eXtended Module and offers 16-bit sampled instruments, as well as instrument envelopes, MIDI keyboard input, and a great interface. Up to 32 channels.

Programming Languages

Pascal: A high-level language created by Niklaus Wirth.

C/C++: A "middle-level" language created by K&R in 1970.

Assembly: A low-level language that more than half of all demos are programmed in. Very tough to learn, but very fast and offers total control of the computer.

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