Sidfiles usually have one of the following file name extensions: .sid, .dat, .inf, .DAT, .SID, .INF, .c64, .prg, .C64, .PRG, .info, .INFO, .data, .DATA
Preferred default file extension for single-file sidtunes sidtune description files in SIDPLAY INFOFILE format.
Common file extension for single-file sidtunes due to SIDPLAY/DOS displaying files *.DAT in its file selector by default. Originally this was intended to be the extension of the raw data file of two-file sidtunes in SIDPLAY INFOFILE format.
Extension of Amiga Workbench tooltype icon info files, which have been cut to MS-DOS file name length (8.3).
No extension for the raw data file of two-file sidtunes in PlaySID Amiga Workbench tooltype icon info format.
Common upper-case file extensions from MS-DOS (unconverted).
File extensions used (and created) by various C64 emulators and related utilities. These extensions are recommended to be used as a replacement for ".dat" in conjunction with two-file sidtunes.
Uncut extensions from Amiga.