John H Sorg

US Patent:

55264840, Jun 11, 1996

Filed:

Dec 10, 1992

Appl. No.:

7/988549

Inventors:

Daniel F. Casper - Poughkeepsie NY
John A. deVeer - Millbrook NY
Edward Loizides - Poughkeepsie NY
Martin W. Sachs - Westport CT
John H. Sorg - Los Gatos CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1312

US Classification:

39520014

Abstract:

A method and system for pipelining the processing of channel command words is provided. The channel is permitted to send commands and data to the control unit for several channel command words associated with a channel program without having to wait for responses from the control unit for prior commands sent. The channel can pipeline several commands to the control unit and the control unit can then process the commands in the order it receives them. The control unit sends responses to the channel for each command it receives acknowledging receipt of the commands.

US Patent:

42375339, Dec 2, 1980

Filed:

Dec 28, 1978

Appl. No.:

5/973992

Inventors:

Phillip R. Mills - Gilroy CA
Fernando A. Luiz - Monte Sereno CA
John H. Sorg - Los Gatos CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 300

US Classification:

364200

Abstract:

Means are provided to prevent the failure of an Initial Program Load (IPL) command in a data processing system because of a "busy" indication from a Direct Access Storage Device (DASD) control device which is executing the command. An IPL operation from a Central Processing Unit (CPU) involves the issuance of a System Reset signal to all channels and control units connected to the CPU, followed a short time later by a READ IPL command to the DASD control device controlling the DAS device which contains the program to be loaded. The present invention enables the system to distinguish between when a control device is busy with a System Reset procedure and when it is busy on other matters, and to permit the queueing of the READ IPL command when the control unit is busy and there is a System Reset operation pending so that the READ IPL command will not be rejected.

US Patent:

53924258, Feb 21, 1995

Filed:

Aug 15, 1994

Appl. No.:

8/290449

Inventors:

Joseph C. Elliott - Hopwell Junction NY
Kenneth R. Lynch - Rhinebeck NY
Martin W. Sachs - Westport CT
John H. Sorg - Los Gatos CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1100

US Classification:

395575

Abstract:

Retrying a command from a CCW in a data processing I/O system having a channel connected to a control unit in which the channel detects an error condition and requests the control unit to retry the current command of an I/O operation. The control unit then determines if the requested retry can be accomplished, and, if it can, sends a response back to the channel requesting the channel to initiate a retry. After receiving the response, the channel checks to determine if conditions are still present which allow a retry, and if they are, executes the current command to perform the retry. If the control unit determines that a retry cannot be accomplished, the control unit has the option to perform a unit check procedure. If the control unit determines that neither a retry nor a unit check can be accomplished, the control unit has the option to perform a selective reset function.