The above writeup covers only the smaller tape drives associated with personal desktop computers. Mainframe systems used tape drives roughly the size and shape of caskets stood on end, which in turn used reel-to-reel tapes about the size of vinyl albums. That would be twelve inches in diameter, for you young punks who've never seen record albums. I haven't worked as a tape monkey for decades, so I have no idea whether tape drives are still huge and clunky (and the tapes likewise) or whether they've gotten smaller and more compact like everything else in the world of computers.