International Business Machines Corporation

Henry Michael Garrett

William Gavin Holland

Joseph Franklin Logan

Joseph Gerald McDonald

John Kenneth Stacy

Francis Edward Noel, Jr

Warren D Bailey

Anthony D Walker

Lorrie Ann Tomek

Gregory Francis Paussa

Michele M Ferris

Erik L Dixon

A method for transferring data between non-contiguous buffers in a memory and an I/O device via a system I/O bus uses a descriptor queue stored in memory. Each descriptor points to a buffer and includes the length of the buffer. The I/O device is provided with the base address of the queue, the length of the queue and a current address which at initialization is the same as the base address. When data is to be transferred a device driver located in the processor sends the number of available descriptors (DescrEnq) to the I/O device which accesses the descriptors individually or in burst mode to gain access to the data buffers identified by the descriptors.

Efficient data transfer mechanism for input/output devices having a device driver generating a descriptor queue and monitoring a status queue

Efficient data transfer mechanism for input/out devices having a device driver generating a descriptor queue and monitoring a status queue

Efficient data transfer mechanism for input/output devices

Multiple stations, such as Personal Computers, are awakened (restored to full power) by a specially formatted Local Area Network (LAN) frame termed 'Wake Multiple Over LAN'. The frame includes a header field containing Destination Addresses, DA, of stations to be awakened and a data field containing a Group Address (GA) or Universal Wake-Up Address (UWUA). The receiving station parses the frame and if the station is a member of the group, it is returned to full power.

Wake multiple over LAN

An interrupt mechanism associated with a peripheral devise is connected to a processor by an interrupt driven I/O bus. The mechanism includes an n input System Interrupt Status Register (SISR) which collects up to n different interrupts from the device during a predetermined time period. Gate and timing circuits under control of signals provided by the processor regulate the frequency of the interrupts thus reducing the number of interrupt operations required to service the device.

System for collecting a specified number of peripheral interrupts and

A system (such as a multiprotocol LAN adapter) for use in a workstation or other processing machine automatically determines the type of network to which the workstation is connected and for automatically determines the type of physical medium to which the workstation is attached. The system has a plurality of different physical ports for supporting various available physical media over which network data may be transmitted. For example, the system may have a port for connecting to shielded twisted pair (STP) wiring, a port for connecting to unshielded twisted pair (UTP) wiring, a port for connecting to coaxial cable, and a port for supporting the Attachment Unit Interface (AUI). Connected to each of these physical ports are various network interface devices for supporting the various available networking protocols, e.g., token ring, Ethernet, etc. Logic circuitry and control software are connected to the network interface devices. In order to determine the valid network connections to the individual ports, a short interrogation frame is successively transmitted by each of the network interface devices to each of the ports. Depending upon the status of each transmission, the system determines what type of network (if any) is connected to and by which type of physical medium. Based upon these two determinations, the workstation can be automatically configured without user intervention.

System and method for determining network connectivity

Growing community of inventors

Raleigh, NC, United States of America

Henry Michael Garrett