Demo (computer Programming) - Size Restrictions

Size Restrictions

Small file sizes have been an integral feature of certain types of demos from the very beginning, when software crackers needed to squeeze a crack intro into a very small leftover area of a floppy disk or RAM. It was also important for BBS advertisement intros to be relatively small, since they were typically included in every file downloaded from the BBS.

Sometimes even the platform itself dictated some size restrictions: the size of the boot sector of a floppy disk (generally 512 to 4096 bytes) was also the maximum size of a boot block demo. The common 64-kilobyte size limit for intros, on the other hand, was the segment size in the 16-bit x86 architecture and also the maximum size of an MS-DOS-based .COM executable.

In later times, the practical need for very small demos had diminished, but the willingness to compete in squeezing much into little space had not disappeared. It was therefore necessary to introduce artificial size restrictions in order to challenge the authors. In modern demoscene events, there are demo competitions with relatively loose size restrictions, and intro competitions with quite strict limits of 64 kilobytes or less.

Because of the strict size limits, intros show off the programmer's ability to squeeze much into little space, often by generating graphic and sound data rather than just reading it from a datafile. Because of the extremely low size limit, 4K intros used to lack sound, or had extremely low quality music. As technology progresses, however, 4K sound synthesis has become a new frontier in the demoscene. 4K still isn't the lowest border for demosceners: some demoparties organize 1K, 256 byte, 64 byte or even 32 byte intro competitions. While creating a 4K might not require low-level programming knowledge anymore, sub-1K competitions require the demo coder to be skilled in both assembly programming and algorithmic optimization. (For comparison: The size of this section of article is over 2 kilobytes.)

Procedural generation techniques developed for small intros have worked their way into mainstream gaming such as Will Wright's recently released game Spore.