[timthorn]

It's pedantry and missing your point about progression to 3.5", but given this is wallowing in retro - you can't forget that the ZX Spectrum went to Microdrive and then, with the Spectrum+3, to the 3" (not 3.5") floppy :)

https://www.sintech-shop.co.uk/zx-microdrive/a-3035/

https://www.dataserve-retro.co.uk/contents/en-uk/d56.html