Tape Drive.
Tony,
Because if my memory is correct (and it's often faulty), QIC-02
required a format on the tape before use…it wasn't a streaming protocol.
Also, in the "early" days…many folks separated the unit controller from
the unit itself such as the old hard drive controllers and "stupid" drives.
Thus came the ST-506 drives, controllers, bus, etc. I presume the same
applied to the original QIC tape drives.
Nowdays, the controller is built into the unit along with an
interface adapter.
Don