Abstract: A small, high performance magnetic tape transport system for use in recording and reproducing data is adapted to receive a cartridge in which a single supply reel for the magnetic tape medium and the magnetic tape are carried. The cartridge is capable of being easily loaded into the transport system for recording (writing) and reproducing (reading), and is also easily ejected from the system for storage or replacement. A driving mechanism for the reel in the cartridge and a permanent take-up reel or hub are carried by the transport. The separate cartridge driving mechanism and take-up hub are each driven by their own separate motor system. In the embodiment disclosed, means are taught for automatic threading of the tape using a semi-rigid leader having a coupling portion attached to the take-up hub, the to-be-threaded tape including a complimentary coupling portion.