The Opus Discovery is a floppy disk interface for the ZX Spectrum.
Opus uses the WD1770 FDC chip.
3.5" hard cased disks as used with Amstrad and Tatung computers.
Number of drives per system: 2
Storage capacity: 180 Kbytes per side
Number of tracks: 40
Number of sectors per track: 18
Sector size: 256 bytes
Formatting: approx. 17.5 sec
Cataloguing: approx. 4sec
Loading a screen: approx. 4sec