[NikkiA]

The spectrum didn't have an official (**) floppy disk add-on, the official mass storage upgrade* was the microdrive, which was a 100kB tape loop format - an improvement on cassettes, but not by much.

As a result, there was a wide range of unofficial floppy disk addons, which then brought the issue that there were so many competing products that supporting them all was near impossible and hardly any commercial software bothered.

Post main-popularity, most people settled on the Beta Disc / Beta 128 from Technology Research as being the main unofficial standard, somewhat bolstered by it being adopted in eastern europe and russia, but during the main popularity period, even it had really poor market share in the UK.

* There was also the cartridges for the Interface 2, but that's a different beast entirely and they were even less common than the Interface 1 + microdrive.

** of course there was the Spectrum +3 near the end of the spectrum's life which had a built-in 3" amstrad drive, which saw reasonable commercial support, but it was long after the main portion of the spectrum's popularity, and at a time when the ST and Amiga were beginning to dominate.