blippo - No, it’s not impossible. You seem to have missed this sentence a bit further into the paragraph that you quoted:
… made by Toshiba. I could also use it to boot PCs (with a suitable boot floppy), which was what I was mainly wanting.
By contrast, this one sold by Amazon UK: http://www.amazon.co.uk/gp/product/B00028MGS4 said on the box that it wouldl read 720KB disks and could be used to boot PCs, but I had three from Amazon (all returned) that would do neither when I tried them with the same PCs with which the Toshiba drive worked successfully.
(I can’t find the Toshiba drive still for sale.)