Leonard A Weiss, 647242 Ayrshire Ln, Boca Raton, FL 33496

4468734, Aug 28, 1984

Mar 26, 1982

6/362414

Charles S. Lanier - Delray Beach FL
Hiram M. Maxwell - Boca Raton FL
Roger E. McKay - Boca Raton FL
Leonard Weiss - Hollywood FL

International Business Machines Corporation - Armonk NY

G06F 1516

364200

A method of initializing non-synchronous peer-to-peer data communication rings, and for effecting error recovery in such networks. On detection of error, each station operates in a purging configuration to clear the ring. In the purging configuration the station's receiving circuits are isolated and its transmitting circuits transmit "clear" signals containing this station's own address as destination. These signals serve to purge all potentially erroneous information in all upstream stations which then are operationally connected to that station. If a loss condition is persistent the station operates first in a "bypass" configuration for a third predetermined time interval, then in the purging configuration for the second time interval, and then resumes normal operation. In the bypass configuration the station's ring input is connected directly to its output and the (locally clocked) output of its transmitting circuits is connected to the input of its receiving circuits. This serves to restore reception clocking in temporary alignment with the local transmission clock source.

4354229, Oct 12, 1982

Mar 10, 1980

6/129052

Jonathan B. Davis - Boca Raton FL
Charles S. Lanier - Delray Beach FL
Daniel T. W. Sze - Boca Raton FL
Leonard Weiss - Hollywood FL

International Business Machines Corporation - Armonk NY

G06F 1516

364200

In a loop-structured communication system interconnecting a plurality of data processors without central controller, stations comprise modems which can start loop operation and achieve synchronous frame transmission around the loop through all participating stations. In an initialization procedure after system start or after loss of frame synchronization on the loop, modems select a temporary master station. The temporary master will adapt total loop delay to be an integer multiple of the basic frame period, and will transmit available frames. All active modems adapt their timing to the circulating stream of frames until the whole loop and all participating stations are synchronized. Synchronization conditions are continuously monitored in all stations to start resynchronization or initialization procedures if necessary. In a specific arrangement, the location of a loop failure which prevents establishment of synchronization can be determined.

4489379, Dec 18, 1984

Jan 25, 1982

6/342439

Charles S. Lanier - Delray Beach FL
Hiram M. Maxwell - Boca Raton FL
Roger E. McKay - Boca Raton FL
Leonard Weiss - Hollywood FL

International Business Machines Corporation - Armonk NY

G06F 304

364200

In a ring-structured data communication network, in which plural data processing systems exchange data and control information on a full duplex peer to peer basis, systems are presently architected to assign at least three I/O subchannels (i. e. at least three device addresses) to respective ring interface adapters. At least two of these subchannels are dedicated for providing separate input paths from the ring to at least two associated program-assignable areas in their system's main store, and a third of these subchannels is dedicated as an output path from the system's store to the ring. Collectively, these subchannels can sustain two input transfer processes and one output transfer process concurrently. One of these input processes is associatable with a locked mode of adapter operations which provides a non-blockable path for data transfer from a selected (remote) station on the ring to the respective system's main store. In this mode the other input subchannel and the output subchannel permit the system to maintain full duplex communication with other ring stations in respect to network transactions/processes which may require priority attention.