Modular unitary disk file subsystem

A rotating disk memory accessory subsystem module for attachment and use entirely within a housing of a host computer at one of a plurality of accessory plug-in location originally provided for a single, substantially flat electronics printed circuit accessory card, the slot location having predetermined actual length and height dimension constraints and a nominal width dimension constraint for a printed circuit accessory card, said width dimension constraint being defined by the distance between adjacent accessory plug-in slot locations, and said length and height dimension constraints being limited by the internal dimensions of said housing, and each of the slot locations further having at least one multiple signal path receptacle aligned and extending longitudinally along a lower attachment surface providing electrical connection to data, address and control buses of the host computer, said subsystem module including:

• support frame means for supporting, aligning and providing electrical interconnection of:
• a rotating disk assembly including a radially positionable head transducer for flying in close proximity to a data storage surface of at least one rotating data storage disk upon an air bearing created by rotation of said disk, and wherein the data storage surface lies in a plane which is substantially parallel when the subsystem module is installed at the said one slot location to a plane defined by the length and height dimension constraints of the said one location and which plane passes through a longitudinal axis of the said at least one multiple signal path receptacle, and
• printed circuit board means for carrying electronics circuitry including:
• at least one multiple signal path edge connector aligned and extending along an edge of said printed circuit board means for mating with said at least one multiple signal path receptacle thereby providing direct plug-in attachment, connection and use of said subsystem module with the host computer without cabling at said one slot location, and
• said electronics circuitry including:
• data transducer position control means for controlling the radial position of the head transducer in relation to user data block locations on the data storage surface,
• disk user data controller means for controlling the formatting, storage and retrieval of user data blocks to and from the storage surface via the head transducer, and
• interface means connected to said at least one multiple signal path edge connector, said data transducer position control means and said disk user data controller means for obtaining control signals and data blocks from the host computer for storage of said data blocks on the data surface, and for supplying control signals and retrieving data blocks from the data surface and sending said supplied control signals and retrieved data blocks to the host computer via electrical signal paths through the said connector and the said receptacle,
• wherein said support frame means, said rotating disk assembly, and said printed circuit board means including said edge connector and said electronics circuitry of the subsystem module are positioned entirely within the actual length and height dimension constraints of the said one slot location entirely within said housing, location, and lie sufficiently within the width dimension constraint thereof without vertical extension and overhang above adjacent slot locations so that slot locations of the host computer situated directly adjacent to the said one slot location are capable of receiving and being occupied by additional structure providing said host computer with at least one additional accessory function when the said subsystem module is installed at the said one slot location of the host computer.