Mark B Stephens

US Patent:

57874611, Jul 28, 1998

Filed:

Aug 12, 1996

Appl. No.:

8/695405

Inventors:

Mark Stephens - Burlingame CA

Assignee:

Roadrunner Technology, Inc. - San Mateo CA

International Classification:

G06F 1300

US Classification:

711113

Abstract:

A high speed compact disk read only memory drive. In one embodiment, a local storage device containing an optical disk drive, a fast local storage device and RAM are all coupled to controller circuitry. The controller circuitry is coupled to interface circuitry which may be coupled to the bus of an ordinary computer system. The data storage device behaves and responds similar to an ordinary CD-ROM, DVD or hard disk drive to the coupled computer system. The RAM of the disclosed data storage device is configured to store directory information and the local storage device is configured to store executable files from the optical disk drive and cache non-executable data. Non-executable data is replaced in the local storage device in accordance with a least recently used algorithm. Information requests from the coupled computer system are read directly from the RAM or the local storage device as requested with significant increases in read access time and data transfer rates.

US Patent:

41715098, Oct 16, 1979

Filed:

Jan 19, 1978

Appl. No.:

5/870620

Inventors:

Mark L. Stephens - Campbell CA
Paul R. Gray - Orinda CA

Assignee:

Signetics Corporation - Sunnyvale CA

International Classification:

G01L 118

US Classification:

323 75C

Abstract:

A bridge circuit for a measurement bridge of the type using four impedance arms provides an output referenced to ground which is a function of the impedances in the respective arms. The bridge circuit includes an impedance bridge comprising first, second, third and fourth impedance arms connected in series loop with first, second, third and fourth bridge terminals serially defined at the connections between the respective arms. A source of constant current is connected between the first terminal and ground. A driver is connected to bridge terminals other than the output terminal. The driver is responsive to bridge terminal signals to provide a bridge output which is a function of the impedances in the respective arms.

US Patent:

40500314, Sep 20, 1977

Filed:

Mar 1, 1976

Appl. No.:

5/662462

Inventors:

Paul R. Gray - Orinda CA
Mark L. Stephens - Campbell CA

Assignee:

Signetics Corporation - Sunnyvale CA

International Classification:

H03F 310
H03F 316

US Classification:

330 24

Abstract:

An amplifier circuit and structure having high input impedance and having a return path for conducting amplifier DC leakage current. A common diode structure forms the return path and includes two diodes connected in series and connected in opposite conduction directions. The diode having a forward conduction direction which is in the opposite direction of the leakage current is provided with a reverse saturation current which is substantially greater than the leakage current of the amplifier. The amplifier is typically a P channel or N channel field effect transistor (FET) and the double diode structure is typically an NPN or PNP transistor.

US Patent:

41662695, Aug 28, 1979

Filed:

Mar 6, 1978

Appl. No.:

5/883486

Inventors:

Mark L. Stephens - Campbell CA
Paul R. Gray - Orinda CA

Assignee:

Signetics Corporation - Sunnyvale CA

International Classification:

G01L 122

US Classification:

338 3

Abstract:

A temperature compensated piezoresistive transducer includes a silicon body having a major top surface and an under surface. The body has generally parallel spaced first and second elongate slots formed therein extending through said top and under surfaces to define a center portion between said slots and first and second outer portions at the outward edge of the respective slots. The center portion is adapted to receive pressure to be measured. The body has an additional slot extending through the top and bottom surfaces and extending around the first, second and center portions to define the outer periphery of a transducer membrane with portions of the body remaining to integrally support the membrane. Plural piezoresistive elements having elongate and transverse dimensions are formed on the membrane. The elements are arrayed to receive compressive and tensile stress when pressure is applied.