comp.sys.sinclair FAQ

File Formats

Tape File Formats:
Files stored in one of the following formats can be used to reproduce exact (or near-perfect) duplicates of the original source tape. For this reason, they are generally preferred to 'snapshot' files, although they are slightly less well supported. Additional information regarding the intended hardware type (for example) can often be encoded with files of this type, and custom loading systems are both reliably and accurately preserved.

Snapshot File Formats:
Snapshot files represent the contents of the system memory at a particular moment in time. As a result of this, they can be loaded into an emulator almost instantaneously, but cannot normally be used to recreate the original tape. Please note that the .z80 format is now located on a different page.

Disk File Formats:
There are relatively few disk formats in common use by modern emulators, with .dsk and .trd being the most popular. Virtually all modern emulators support one (often both) or more of the following:

Emulator-specific Formats:
The following formats are (currently) tied to individual emulators, and provide specific features or make special allowances for the emulator in question. Few of these formats are well documented by their authors, so providing accurate specifications can be difficult; Warajevo DCK and Spectaculator SZX are noteworthy exceptions.

Other/Miscellaneous Formats:
The formats used to store Microdrive cartridge images, loading screens/titles and to capture emulator input for later playback are documented below, with links to more detailed specifications where available. Of the formats listed, only .scr and .pok are very widely supported across multiple platforms, although .rzx is becoming increasingly popular. The .mdr format is supported by Spectaculator v4.0 and above, RealSpec and XZX-Pro, plus others.