.SID File Extension

Image created using Multi-resolution Seamless Image Database (MrSID) compression, which was developed by LizardTech for compressing large images; commonly used to partition and store large Geographic Information Systems (GIS) images.

Backup file created by Steam, an application used to download and manage Valve video games on desktop computers; contains compressed game data created by the Steam backup feature (steambackup.exe program); used to backup games to DVDs or other external media.

SID files are created with a .SIS file and a .SIM file, which provide metadata necessary to restore backup game data. SID files use the naming convention {game}_disk{X}_{Y}.sid, where "game" is the name of the backup game, "X" is the disk number, and "Y" is the backup file number on the disk.

NOTE: Steam backups do not include saved games, custom multiplayer maps, or configuration files. You must backup and restore those files manually.

Music file format used by the Commodore 64 (C64) system; commonly included with C64 video games for intro or background music; may also be used for creating songs with other C64 music software.

SID music files can be saved in mono or stereo audio formats.

Sound file format originally used by Commodore computer systems; formatted for the MOS Technology 6502 processor, but can be played back by software players that emulate the processor.

SID files may be saved in the PSID format or the newer RSID (Real SID) format. PSID files are more compatible with software emulation programs, while RSID files require more complete emulation of the C64 hardware.