David H Wu

US Patent:

41886658, Feb 12, 1980

Filed:

Nov 29, 1977

Appl. No.:

5/855572

Inventors:

Dennis M. Nagel - Boca Raton FL
Douglas O'Neal - Boca Raton FL
Paul W. Petroskey - Boca Raton FL
Jan W. van den Berg - Boca Raton FL
Donald V. Wildes - North Lauderdale FL
David C. Wu - Delray Beach FL

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 304

US Classification:

364200

Abstract:

A micro processor controlled user programmable communications multiplexer subsystem (herein referred to by the symbol PCS) capable of transmitting and receiving data on any one or more of 32 communications lines simultaneously. Each line may be dynamically assigned to a variety of communication characteristics, such as line speeds, character lengths, synchronous, or asynchronous operation, and code structures as well as protocol selections. The system of the invention provides the capability for the user to write his communications programs using novel operations commands that provide code structure and protocol independence as well as communication line independence. Various hardware features and queuing techniques are employed in order to maintain high transmission rates. Variable line scanning in the Teleprocessing Time Division Multiplexer of the PCS is programmably permissible; i. e. , the time base for line scanning is fixed and is a multiple of the communication line rate, although the actual line to be scanned is programmably variable.

US Patent:

55309631, Jun 25, 1996

Filed:

Dec 16, 1993

Appl. No.:

8/168693

Inventors:

Victor S. Moore - Delray Beach FL
Richard G. Van Duren - Big Torch Key FL
David C. Wu - Boca Raton FL

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1300

US Classification:

39520015

Abstract:

A method and system for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation wherein individual segments within the multisegment local area network are interconnected by a router device and wherein selected segments within the multisegment local area network include radio frequency transceivers adapted to provide a wireless communications link with mobile workstations. Each time communication is established between a mobile workstation and a selected workstation within the multisegment local area network via a radio frequency transceiver a routing table entry is established which identifies a segment location for the mobile workstation within a routing table associated with each router device within the multisegment local area network. A routing table entry is also established which identifies a segment location for the selected workstation within the routing table associated within each router device within the multisegment local area network in response to each attempt at establishment of communication between the selected workstation and the mobile workstation. Thereafter, all routing table entries which identify the segment location for a mobile workstation are automatically deleted in response to a termination of communications between the mobile workstation and the radio frequency transceiver.

US Patent:

52991369, Mar 29, 1994

Filed:

Jun 5, 1991

Appl. No.:

7/711466

Inventors:

Jacquelin Babakanian - Boca Raton FL
James W. Davis - Delray Beach FL
Mark S. Garvin - Boca Raton FL
Robert M. Swanson - Boca Raton FL
Nandor G. Thoma - Boca Raton FL
David M. Wu - Boca Raton FL

Assignee:

International Business Machines Corp. - Armonk NY

International Classification:

G06F 1520

US Classification:

364488

Abstract:

Groups of DCVS (Differential Cascode Voltage Switch) circuits are interconnected by single-track data transfer connections. Each group contains one or more DCVS tree circuits, through which data signals propagate only on dual-track connections. In each group, at least one DCVS tree circuit is configured as an input boundary tree, and at least one tree circuit is configured as an output boundary tree. All data inputs externally applied to a group, are transferred only through input boundary trees of the group, and all data outputs transferred out of a group leave the group only through output boundary trees of the group. If a group has only a single tree, that tree serves as input and output boundary tree of the group. Each input boundary tree of each group has one or more associated primary shift register latch (SRL) circuits through which all external data inputs to that tree are transferred. Such external data inputs are received through the single-track connections mentioned above.