The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 20, 1999
Filed:
Dec. 30, 1996
Bruce Blaho, Fort Collins, CO (US);
Courtney Goeltzenleuchter, Fort Collins, CO (US);
Russ W Herrell, Fort Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A system and method for virtual device access in a graphics computer is disclosed. The present invention enables applications running on a graphics computer to access the graphics hardware device with no per-transaction performance cost. Each time an application attempts to access the graphics hardware device, a hardware control manager either gives the application access to the graphics hardware device if no other application is currently accessing the hardware, or alternatively, if another application is currently accessing hardware, the hardware control manager instructs a signal handler associated with the application attempting access to perform a graphics context switch with the currently accessing application before the hardware control manager will give permission to the application attempting access to access the graphics hardware device. An important feature of the present invention is that the device dependent features are provided by user level code via the signal handler whereas the hardware control manager supports only device independent features. Another important feature of the present invention is the ability to automatically control data flow without incurring additional overhead.