A method for using a modular unitary disk file subsystem

A method enabling a user to store and transport data among selected ones of a plurality of compatible personal computers, each having compatible operating systems and expansion slot locations located entirely within the housing of each of the plurality of compatible personal computers for receiving printed circuit electronics expansion boards, the method comprising the steps of:

• (a) forming a rotating disk memory accessory subsystem module as a single unit comprised of an enclosed fixed disk assembly including a plurality of non-removable disks, at least one of which is a data storage disk, disk motor means for rotating the disks as a predetermined angular velocity, at least one data transducer for flying in close proximity to a data storage surface of said data storage disk upon an air bearing formed by rotation of the disk relative to the data transducer, a head transducer arm for mounting the data transducer for relative movement among selected radially displaced data blocks on the disk storage surface, powered mover means for moving the head transducer arm, the subsystem module further comprising electronics circuitry including data transducer position control means for controlling radial position of the head transducer in relation to user data blocks 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 for obtaining control signals and data blocks from the said one of the compatible personal computers 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 to the said one of the compatible personal computers via its expansion slot location into which said subsystem module is installed, said subsystem module being so formed as to withstand multiple insertions and withdrawals from each said expansion slot location and as to occupy substantially no greater space than that allotted to a printed circuit electronic expansion board so that slot locations located directly adjacent to the said one slot location are capable of receiving and being occupied by additional structure providing said personal computer with at least one additional accessory function when the said subsystem module is installed at the said one slot location of the personal computer;
• (b) installing the subsystem module so formed at a said expansion location of a selected one of said compatible personal computers without any special skills or special tools being required by the user and without the use of any cabling;
• (c) recording user data blocks supplied from the said one of the compatible personal computers onto said data surface via the head transducer;
• (d) removing the subsystem module from the said one of the compatible personal computers without any special skills or special tools being required by the user;
• (e) subsequently reinstalling the said subsystem module into an expansion slot location of a subsequently selected one of the compatible personal computers without any special skills or special tools being required by the user;
• and
• (f) subsequently reading said recorded user data blocks and transferring them to said subsequently selected one of the compatible personal computers via the interface means of the subsystem module and the expansion slot location of the said subsequently selected one of the compatible personal computers.