R-Byte, Inc.

Advanced System Products, Inc.

Ta-Lin Chang

Yu-Ping Cheng

Shih-Tsung Hwang

David R Lee

Edward J Rhodes

Clifford R Berry

Daryl K Adams

A host adapter contains a RISC processor, a local memory, and a memory management unit that permits the RISC processor and a host computer system to access a local memory. The host computer system writes command descriptions directly into the local RAM. The RISC processor retrieves and processes the command descriptions. The local RAM may be divided into numbered command description blocks having a fixed size and format. In standard bus protocols, such as SCSI-2, block numbers are used as tag messages. Such tag messages allow the host adapter to quickly identify information used when an SCSI I/O request is resumed. The command description blocks may be linked into lists, including an active list containing command description blocks that are ready for the RISC processor and a free list containing command description blocks that are available for use by the host computer.

System for host accessing local memory by asserting address signal

In a digital data storage audio tape system having a host device interface unit, a main data buffer manager, a main data buffer, a processor, a data separator, a tape drive unit, and a read/write channel, this invention comprises a formatter providing track construction, encoding and decoding, error correction, and direct memory access of digital data transmitted between the host device unit and the tape drive unit and a frame buffer for buffering digital data for encoding and decoding, and error correction. The formatter is coupled between the main data buffer manager, via a direct memory access channel, and the read/write channel of the tape drive, and further is coupled to the frame buffer. The formatter is coupled to and responsive to instruction control by the processor in conjunction with instruction control of the tape drive unit by the processor.

Digital data storage tape formatter

Growing community of inventors

Cupertino, CA, United States of America

Ta-Lin Chang