John W Irwin

US Patent:

53218108, Jun 14, 1994

Filed:

Aug 21, 1991

Appl. No.:

7/748353

Inventors:

Colyn Case - Amherst NH
Kim Meinerth - Middleton MA
John Irwin - Hudson NH
Blaise Fanning - Overland Park KS

Assignee:

Digital Equipment Corporation - Maynard MA

International Classification:

G06F 1500

US Classification:

395166

Abstract:

In a computer graphics system, an address generator processes physical and virtual addresses using a common command set. The address generator formulates addresses as a function of distance from the origin of the desired destination area in a destination memory to the requested position in the destination area. A plurality of context drawing commands is used to define a desired context in which drawing graphics commands operate. Different parts of the context are changeable/redefinable independently of the other parts. Graphics commands have a format of multiple fields having corresponding parameters arranged in order of common use of the parameter such that fields of less commonly used parameters are at an omittable end of the format. Raster drawing commands are delimited by a beginning and end indicator to form a drawing unit. For clip list processing, a drawing unit is stored as a single occurrence in the system command buffer.

US Patent:

53156960, May 24, 1994

Filed:

Aug 21, 1991

Appl. No.:

7/748352

Inventors:

Colyn Case - Amherst NH
Kim Meinerth - Middleton MA
John Irwin - Hudson NH
Blaise Fanning - Overland Park KS

Assignee:

Digital Equipment Corporation - Maynard MA

International Classification:

G06F 1562

US Classification:

395133

Abstract:

In a computer graphics system, an address generator processes physical and virtual addresses using a common command set. A separate translator provides conversion from generated virtual addresses to physical addresses. The address generator formulates addresses as a function of distance from the origin of desired destination area in destination memory to the requested position in the destination area. A plurality of drawing graphics commands specify different raster drawing operations. A plurality of context graphics commands is used to define a desired context in which drawing graphics commands operate. The defined context includes destination location for resulting data, type and plane depth of graphics operations, foreground and/or background color of resulting data. Different parts of the context are changeable/redefinable independently of the other parts.

US Patent:

53156986, May 24, 1994

Filed:

Aug 21, 1991

Appl. No.:

7/748354

Inventors:

Colyn Case - Amherst NH
Kim Meinerth - Middleton MA
John Irwin - Hudson NH
Blaise Fanning - Overland Park KS

Assignee:

Digital Equipment Corporation - Maynard MA

International Classification:

G06F 1520

US Classification:

395162

Abstract:

In a computer graphics system, an address generator processes physical and virtual addresses using a common command set. A separate translator provides conversion from generated virtual addresses to physical addresses. The address generator formulates addresses as a function of distance from the origin of desired destination area in destination memory to the requested position in the destination area. A plurality of drawing graphics commands specify different raster drawing operations. A plurality of context graphics commands is used to define a desired context in which drawing graphics commands operate. The defined context includes destination location for resulting data, type and plane depth of graphics operations, foreground and/or background color of resulting data. Different parts of the context are changeable/redefinable independently of the other parts. The graphics commands have a format of multiple fields.

US Patent:

53218060, Jun 14, 1994

Filed:

Aug 21, 1991

Appl. No.:

7/748360

Inventors:

Kim Meinerth - Middleton MA
Colyn Case - Amherst NH
Ali Moezzi - Chelmsford MA
John Irwin - Hudson NH
Agnes Masucci - Haverhill MA
Srinivasan Krishnaswami - Shrewsbury MA

Assignee:

Digital Equipment Corporation - Maynard MA

International Classification:

G06F 1520

US Classification:

395162

Abstract:

A residue buffer, for temporary storage of portions of transmissions from a CPU to a graphics processor. Graphics commands are transmitted, in transmission units of uniform size, from a processor unit to an address generator, which processes the commands. The portion of the transmission unit not immediately usable by the graphics processor is stored in the residue buffer. The disclosure further describes a computer graphics system, having a graphics processor capable of reading from or writing to main memory, including virtual memory, without any action by the CPU; having a duplicate cache tag store accessible by the graphics system without generating traffic on the system bus; having a FIFO command buffer in main memory for temporary storage of graphics commands; having a "short circuit" feature for routing graphics commands to the command processor in the minimum number of steps; having a cursor control system capable of storing cursor pattern information in, and retrieving cursor pattern information from, main memory; having a cursor bus that is reconfigurable to carry information other than cursor information; and having a frame buffer module that contains no timing or cursor control circuitry.