Disc memory apparatus magnetic head carriage manual control

摘要

An open loop, stepper-motor driven, rigid magnetic disc memory apparatus for use with a data processing system. A rigid magnetic disc with high track density is driven by a stepper motor in an open-loop fashion or without servomechanism control. The memory apparatus includes: band structure including a spring bias for coupling stepper motor drive to apparatus supporting magnetic heads above and/or below the spinning disc and for temperature compensating for disc/apparatus expansion and contraction; manually operable control for zeroing the magnetic heads, moving and locking them in the disc's landing zone as, for example, while in transit, and providing a travel limit to head movement when the memory apparatus is operating keying apparatus for preventing erroneous insertion and mis-alignment of and damage to an optical transducer relative to an optical mask arranged to spin with the disc structure; shim apparatus for precisely positioning the magnet heads in the spin axis direction; viscously-coupled inertia apparatus for damping the stepping motor's step-rotary motion; a device for employing spinning motion associated with the disc for cooling purposes; and other structure.