Really? My first floppies were eight inches or something like that. I, too, have a bunch in my basement with nothing to read them on.
ML/NJ
Never heard of an 11" floppy and I've been in the computer biz for 30 years ... but then again, who knows, perhaps they did exist and never really made it to prime time.
Eight inch was a standard for a long time, with RadioShack I believe and then IBM's 'DataMaster' as well as their 3740 key to disk system. 5&1/4 had a much longer life time with the advent of the PC.