John S Roberson

US Patent:

60610697, May 9, 2000

Filed:

Jul 26, 1996

Appl. No.:

8/687854

Inventors:

Charles Ray Johns - Austin TX
Christopher Mark LeBlanc - Austin TX
Richard Jesse Mitchell - Austin TX
John Thomas Roberson - Austin TX

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06T 1100

US Classification:

345435

Abstract:

A method and apparatus for moving pixel data from one area of a frame buffer to another in block fashion are provided. In one embodiment of the invention, pixel data is decomposed into its RGB component and each RGB component is stored into the frame buffer in a particular memory bank. The pixel data is moved by moving all the components of the data stored in a memory bank before moving the components in other memory banks.

US Patent:

57901252, Aug 4, 1998

Filed:

Apr 22, 1996

Appl. No.:

8/636093

Inventors:

Thuy-Linh Tran Bui - Austin TX
Charles Ray Johns - Austin TX
John Thomas Roberson - Austin TX
John Fred Spannaus - Austin TX

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06T 1100

US Classification:

345435

Abstract:

Graphics information is efficiently transferred from a host computer to a graphics subsystem in which rendering and pixel data is generated by the host system. A masked span operation provides an assist for 3D rendering performed by the system processor of the host and other system resources. Storage of depth, alpha, stencil, and other pixel data is in system memory including one or more ancillary graphics buffers. The main processor of the host system generates pixel data associated with an image. This data is checked against the buffers. As a result of such checking, a mask is generated by the host system. The mask is transferred in burst mode across the host-graphic subsystem PCI bus to the graphics subsystem in combination with span width, and in the case of interpolated color, color base and color increment data, and X,Y coordinate of the first pixel. In the graphics subsystem the mask is employed with the other data to load the frame buffer with the portion of pixel data defined by the mask.

US Patent:

56969473, Dec 9, 1997

Filed:

Nov 20, 1995

Appl. No.:

8/560610

Inventors:

Charles R. Johns - Austin TX
John T. Roberson - Austin TX

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1206

US Classification:

395517

Abstract:

A two dimensional frame buffer memory interface structure is provided. The interface comprises a parallel data bus, a control signal bus, a data cache, and a controller. The parallel data bus transfers a set of pixel data in parallel to the data cache. The control signal bus transfers to the controller a X strobe signal, a Y strobe signal, and a mode signal indicating an interface mode specifying a designated pattern for the pixel data transferred over the parallel data bus. The data cache, controlled by the controller and connected to the parallel data bus, compiles each set of pixel data received over the parallel data bus into the designated pattern of pixels, as indicated by the mode signal. The controller transfers each set of pixel data from the data cache to a two dimensional frame buffer to be stored in the designated pattern at a calculated address, wherein an address in the two dimensional frame buffer is specified by an X address and a Y address and wherein the calculated address for a given set of pixel data is an X address equal to the X address of a previous set of pixel data plus, when a X strobe signal is received for the given set of pixel data, an X increment associated with the indicated interface mode, and a Y address equal to a Y address of the previous set of pixel data plus, when a Y strobe signal is received for the given set of pixel data, a Y increment associated with the indicated interface mode.

US Patent:

57245606, Mar 3, 1998

Filed:

Dec 14, 1995

Appl. No.:

8/572697

Inventors:

Charles Ray Johns - Austin TX
John Thomas Roberson - Austin TX

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06T 160

US Classification:

395510

Abstract:

A graphics adapter having a processor for processing pixel data is provided. The processor transfers the processed data to the graphics memory in sets of slices of pixel data where each transfer provides several slices, each slice being from a unique pixel. In an alternative embodiment, the storage of the processed data is accomplished within a plurality of memory banks, each of the memory banks being used to store slices of consecutive pixels. The invention further provides for concurrently displaying images having different color depths. This is achieved by a method of organizing data of different pixel depths such that they can be interpreted correctly. Furthermore, the invention provides for double buffering the processed data to get a smooth transition from one image to another.