I recently posted this question (and answer) about connecting a 5 1/4" floppy drive to a computer and was directed to post this question to Super User where it has clearly been accepted as on topic. The relationship to this question being about games is obviously a personal one (the disks I'm looking to read are old computer games). My question is about future hardware and backwards-compatibility questions, at what point do they become off topic?
Just my two cents: your question has nothing directly to do with gaming, or more relevantly, hardware directly related to playing video games. There is nothing about trying to use a 5 1/4" floppy disk that is directly related to playing games except for your intent.
In general, if we want any questions at all in the hardware and backwards-compatibility tags, we would want them to be specific to gaming hardware because then the question is directly related to the site topic and is the kind of knowledge one might expect a gaming expert to have.