Micro Technology, Inc.

Unisys Corporation

MIT Technology Corp.

Edward E Asato

Joseph S Glider

Kaushik S Shah

Hoke S Johnson, Iii

Jesse I Stamness

Duc H Trang

Raymond W Morrow

A block transfer data bus having two separate paths, with each element coupled to the bus having the ability to arbitrate for use of one or the other or both of the bus halves. Each bus half includes an address/data bus portion for sending/receiving the data and addresses. A separate control bus portion for each bus half provides certain status signals and a code indicating the type of data on the address/data bus. An arbitration bus provides data request signals from each element to a central arbiter. In addition, a separate grant signal associated with each bus half is provided back to each element from the arbiter along the arbitration bus. A line on each control signal bus indicates whether or not the bus half is busy.

Dual channel data block transfer bus

A memory system having multiple memories and multiple ports. Multiplexing logic couples each of the ports to each of the memories. A sequencing circuit controls the multiplexers so that each port is sequentially coupled to each of the memories in sequence in a repeating cycle. When coupled to each memory, a block of data is transferred. A second port is coupled to a different memory at each point in time, with the two ports being switched simultaneously to avoid overlap. A port desiring access to the system must wait until it can fit into this switching queue so that it can transfer in lock-step with the other ports to a different memory. Each port has a data I/O bus, an address input bus, an address counter and R/W controls.

Method and apparatus for simultaneous, interleaved access of multiple

Write precompensation data is recorded on a disk of a magnetic disk drive indicating the write compensation to be provided for each of a plurality of head/media combination which may have relatively wide variations in performance characteristics. Apparatus is provided for transferring and storing this write precompensation data in the disk controller at start-up and for accessing this stored data during each write operation to provide a 'tailored' write precompensation for the particular head/media combination to be employed for the writing operation.

Magnetic disk write precompensation method and apparatus which takes

Growing community of inventors

Sunnyvale, CA, United States of America

Edward E Asato