Quantum Corporation

Plus Development Corporation

Claude E Camp

Donald C Westwood

David B Jeppson

Eric J Botto

Richard J Blackborow

Scott E Richmond

Peter S Hahn

Rodica Florea

Ian C Felix

Michael J Hassel

A removable and transportable hard disk subsystem is provided for use with at least one computer and includes at least one hard disk module. The module contains a shock mounted, thin and compact micro-Winchester head and disk assembly which plugs into a base housing which is installable entirely within a well of the computer nominally allotted to receive a 51/4 inch half height disk drive. The base housing includes a head positioning and data module loading/unloading portion of the subsystem control electronics and an electromechanical mechanism for automatically loading and unloading the hard disk module. The base housing provides electrical connections for operating the head and disk assembly when loaded therein. The subsystem further includes an adapter board having a host interface portion of the subsystem control electronics and connected by a cable with the control electronics portion of the base housing, the adapter board for connecting the subsystem directly to address, data and control buses of said computer to enable storage and retrieval in the loaded module of host computer data blocks.

Removable and transportable hard disk subsystem

Higher data storage capacity is realized in a self contained fixed rotating disk expansion board subsystem preferably for a single electronics circuit board accessory slot of a host computer. This greater capacity, e.g. 42 megabytes of formatted storage on two 95 millimeter disks, is achieved by use of a plural zone arrangement wherein each zone contains data tracks in which user blocks are recorded and read out at a data rate unique for the zone. An improved phase locked loop within the data separator uses a separate voltage controlled oscillator for each zone and a common charge pump for generating control voltages applied to change the resonant frequency of all of the oscillators. An oscillator disable circuit disables every voltage controlled oscillator other than the selected oscillator, so that it is the only oscillator whose frequency is actually varied by the charge pump during readback/data separation and decode operations. A dual latch circuit extends the margin of a data window in the data separator to ensure that legitimate data bits read back from the data surface are latched for separation. A single microprocessor supervises operations of the subsystem and calculates physical sector location within each zone from logical sector location data supplied by the host computer.

Modular unitary disk file subsystem with differing density zones

Higher data storage capacity is realized in a self contained fixed rotating disk expansion board subsystem preferably for a single electronics circuit board accessory slot of a host computer. This greater capacity, e.g. 42 megabytes of formatted storage on two 95 millimeter disks, is achieved by use of a plural zone arrangement wherein each zone contains data tracks in which user blocks are recorded and read out at a data rate unique for the zone. An improved phase locked loop within the data separator uses a separate voltage controlled oscillator for each zone and a commmon charge pump for generating control voltages applied to change the resonant frequency of all of the oscillators, An oscillator disable circuit disables every voltage controlled oscillator other than the selected oscillator, so that it is the only oscillator whose frequency is actually varied by the charge pump during readback/data separation and decode operations. A dual latch circuit extends the margin of a data window in the data separator to ensure that legitimate data bits read back from the data surface are latched for separation. A single microprocessor supervises operations of the subsystem and calculates physical sector location within each zone from logical sector location data supplied by the host computer.

Modular unitary disk file subsystem having increased data storage

Growing community of inventors

Milpitas, CA, United States of America

Claude E Camp