Richard G Mustain

US Patent:

61082856, Aug 22, 2000

Filed:

Aug 10, 1992

Appl. No.:

7/927788

Inventors:

Harrison L. Freeman - Kasson MN
Thomas Marshall Hoag - Rochester MN
Richard Glen Mustain - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 509
G06F 934

US Classification:

369 48

Abstract:

A directory structure for WORM optical media which supports a multi-level tree structure containing several paths is disclosed. When a user defines the first path on the WORM volume, a file directory group is created for that path. A path directory entry pointing to this file directory group is written to the path directory group. Files having this path name are initially written into the first data file area next to this file directory group. The first data file area grows as data is written into it. When a second path is defined, the first data file area is closed and a second file directory group is created on the WORM volume next to the first data file area, thereby wasting little if any space. The path directory group is updated with a new path directory entry that points to this new file directory group. Files having this second path name are written into a growing second data area.

US Patent:

51290766, Jul 7, 1992

Filed:

Mar 20, 1989

Appl. No.:

7/325578

Inventors:

Harrison L. Freeman - Kasson MN
Richard G. Mustain - Rochester MN
Carol A. Peters - Byron MN
Thomas M. Hoag - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1300

US Classification:

395425

Abstract:

A method of and apparatus for automatically assigning a name to a storage file. This assignment technique is particularly pertinent to storage files used in conjunction with an optical storage system. The automatically assigned name is used throughout the system to identify the storage file for all purposes including loading and unloading the storage file to and from the various drives within the system, initializing the storage file for use, and reading and writing to and from the storage file. Automatic name assignment normally occurs when a storage file is placed within a mass storage library. A name becomes necessary at that time because the storage file is then available to the system. Alternate automatic name assignment also occurs when for any reason the system is unable to read the name written on a storage file. The automatically asigned name may be replaced with a user supplied name upon operator request.

US Patent:

54918073, Feb 13, 1996

Filed:

Mar 20, 1989

Appl. No.:

7/325752

Inventors:

Harrison L. Freeman - Kasson MN
William Jaaskelainen - Oronoco MN
Richard G. Mustain - Rochester MN
Larry D. Shumway - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1202
G11B 1722

US Classification:

395401

Abstract:

A computer system and method for efficiently managing Write Once Read Mostly (WORM) volumes on mass optical storage devices are disclosed. A configuration menu asks the user to enter a threshold percentage from 1-100%. The threshold percentage is multiplied by the volume size to determine a threshold block address. New files are written sequentially to the WORM volume up to but not exceeding the threshold block address, unless a threshold override indicator is enabled. Space on the WORM volume between the threshold block address and the end of the WORM volume is reserved for updated files. Updated files can be stored anywhere on the WORM volume, including above the threshold block address. Reserving space for updated files on a WORM volume allows more updated files to be stored on the same WORM volume as original files, and reduces the number of optical disks required to be read. The threshold percentage can be modified by the user at any time desired.

US Patent:

59499850, Sep 7, 1999

Filed:

Mar 31, 1998

Appl. No.:

9/052474

Inventors:

Stephen A. Dahl - Rochester MN
John C. Endicott - Rochester MN
Peter J. Heyrman - Rochester MN
R. Karl Kirkman - Rochester MN
Richard G. Mustain - Rochester MN
Jon H. Peterson - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 9455

US Classification:

395500

Abstract:

A method and data processing system for emulating a program are disclosed. According to the present invention, the data processing system runs under a first operating system and emulates the execution of a program under a second operating system within a second data processing system. The data processing system includes a memory which stores at least a portion of the first operating system and an emulator comprising a plurality of routines which each emulate an instruction utilized by the first operating system. The memory further includes a simulated mass storage data area which stores at least a portion of the program and a simulated main memory data area. The data processing system further includes a processor which executes instructions within the program under the first operating system by emulation. According to the present invention, the emulator accesses instructions of the program directly from the simulated mass storage data area to minimize emulation overhead. According to a second aspect of the present invention, the data processing system further includes a cache memory comprising a number of cache lines.

US Patent:

59917571, Nov 23, 1999

Filed:

Mar 31, 1998

Appl. No.:

9/052477

Inventors:

Stephen A. Dahl - Rochester MN
John C. Endicott - Rochester MN
Peter J. Heyrman - Rochester MN
R. Karl Kirkman - Rochester MN
Richard G. Mustain - Rochester MN
Jon H. Peterson - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 9455

US Classification:

707 3

Abstract:

A data processing system includes at least one processor and data storage containing an array including N records having value-ordered entries. To find an entry matching a search value, W, a number of records to be searched, is set equal to N, and each of the W records is assigned to either a first set or a second set, where the first set includes X/2 of the W records and X is a smallest power of 2 equal to or greater than W. In response to a determination that the search value precedes the first record within the second set, a binary search of the first set of records is performed to identify a record including an matching entry. If the first entry of the first record within the second set matches the search value, the first record within the second set is identified. However, if the search value follows the first entry of the first record of the second set, the selected record is identified as containing an entry matching the search value only if W is equal to 1, and if W is not equal to 1, W is reset equal to a number of records within the second set and the above steps are repeated until a record containing a matching entry is identified. Following identification of the search value, at least one entry is retrieved from the identified record and contents of the at least one entry are processed within a processor.

US Patent:

49657208, Oct 23, 1990

Filed:

Aug 8, 1989

Appl. No.:

7/393046

Inventors:

Glen R. Mitchell - Pine Island MN
Richard G. Mustain - Rochester MN
Jon H. Peterson - Rochester MN
Lawrence D. Whitley - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 700
G06F 900
G06F 910

US Classification:

364200

Abstract:

In a processor having a real address space larger than its virtual address space, all of the physical memory is addressed by using a separate prefix register associated with each of the address registers to hold both a high-order address portion and a control bit specifying whether the address is to be translated or used as a direct real address.

US Patent:

58190635, Oct 6, 1998

Filed:

Sep 11, 1995

Appl. No.:

8/526611

Inventors:

Stephen A. Dahl - Rochester MN
John C. Endicott - Rochester MN
Peter J. Heyrman - Rochester MN
R. Karl Kirkman - Rochester MN
Richard G. Mustain - Rochester MN
Jon H. Peterson - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 900

US Classification:

395500

Abstract:

A method and data processing system for emulating a program are disclosed. According to the present invention, the data processing system runs under a first operating system and emulates the execution of a program under a second operating system within a second data processing system. The data processing system includes a memory which stores at least a portion of the first operating system and an emulator comprising a plurality of routines which each emulate an instruction utilized by the first operating system. The memory further includes a simulated mass storage data area which stores at least a portion of the program and a simulated main memory data area. The data processing system further includes a processor which executes instructions within the program under the first operating system by emulation. According to the present invention, the emulator accesses instructions of the program directly from the simulated mass storage data area to minimize emulation overhead. According to a second aspect of the present invention, the data processing system further includes a cache memory comprising a number of cache lines.