From Just Solve the File Format Problem
TR-DOS is an operating system for ZX Spectrum personal computer with Beta Disc floppy drive interface. Despite being developed by British company Technology Research Ltd, it was not especially popular in the West, but was more popular in USSR and post-USSR in 80-90s.
|Number of tracks per side||Number of sides||Number of tracks (total)||Number of sectors||Number of bytes|
Diskettes can be dumped to TRD files for use in emulators.