This may not be close enough to what you're looking for, but DEC put the RT11 filesystem on TU58 tapes. They could be used just like very slow floppies. The tape drive took care of locating logical blocks on the tape, essentially providing a block type device to the computer. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/