Method and apparatus for implementing color graphics on a remote computer

• US 20060082591A1
• Filed: 12/05/2005
• Published: 04/20/2006
• Est. Priority Date: 01/04/2002
• Status: Active Grant

• Current Assignee: Don A. Dykes, Theodore F. Emerson
• Original Assignee: Don A. Dykes, Theodore F. Emerson
• Inventors: Emerson, Theodore F., Dykes, Don A.
• Granted Patent: US 7,145,576 B2
• Time in Patent Office: Days
• US Class Current: 345/602
• CPC Class Codes: G06F 3/1454 involving copying of the display data of a local workstation or window to a remote workstation or window so that an actual copy of the data is displayed simultaneously on two or more displays, e.g. teledisplay
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: G09G 5/363 Graphics controllers

Abstract

A method and apparatus captures the color palettes of a video graphics controller of a managed computer to a remote computer to transmit correct color information to a remote computer. A remote management controller may perform this technique independent from the operating system. The managed computer includes a processor and a video graphics controller. The remote management controller snoops a bus, which couples the processor to the video graphics controller, for processor accesses to the EGA and VGA color palettes stored in the video graphics controller. The remote management controller includes an EGA shadow look up table and a VGA shadow look up table that store the snooped information which is used to create correct color information to be transmitted to the remote computer so that it can display the same colors generated at the managed computer.

Claims

1. A method of implementing color graphics on a remote computer, the method comprising the acts of:

(a) creating a copy of EGA color palette information from an EGA color palette of a video graphics controller in an EGA shadow look up table of a remote management controller;

(b) creating a copy of VGA color palette information from a VGA color palette of the video graphics controller in a VGA shadow look up table of the remote management controller; and

(c) using the EGA and VGA color palette information stored in the respective EGA and VGA shadow look up tables to transmit color information to the remote computer.

2. The method, as set forth in claim 1, wherein acts (a) and (b) comprise the act of:

snooping a bus for processor accesses to the EGA color palette and the VGA palette, where the bus couples the processor to the video graphics controller.

3. The method, as set forth in claim 1, wherein acts (a) and (b) comprise the acts of:

reading color palette index values of a frame buffer of the video graphics controller; and

using the color palette index values to index the shadow look up tables to obtain the color values for pixels in the frame buffer.

4. The method, as set forth in claim 1, wherein acts (a), (b), and (c) are performed in the recited order.

5. A method of implementing color graphics on a remote computer, the method comprising the acts of:

(a) creating a copy of EGA color palette information from EGA color palette of a video graphics controller in an EGA shadow look up table of a remote management controller; and

(b) using the EGA color palette information stored in the EGA shadow look up table to transmit color information to the remote computer.

7. The method, as set forth in claim 5, wherein act (a) comprises the act of:

reading color palette index values of a frame buffer of the video graphics controller; and

using the color palette index values to index the EGA shadow look up table to obtain the color values for pixels in the frame buffer.

8. The method, as set forth in claim 5, wherein acts (a) and (b) are performed in the recited order.

6. The method, as set forth in claim 6, wherein act (a) comprises the act of:

snooping a bus for processor accesses to the EGA color palette, where the bus couples the processor to the video graphics controller.

9. A method of implementing color graphics on a remote computer, the method comprising the acts of:

(a) creating a copy of VGA color palette information from a VGA color palette of a video graphics controller in a VGA shadow look up table of a remote management controller; and

(b) using the VGA color palette information stored in the VGA shadow look up table to transmit color information to the remote computer.

10. The method, as set forth in claim 9, wherein act (a) comprises the act of:

snooping a bus for processor accesses to the VGA color palette, where the bus couples the processor to the video graphics controller.

11. The method, as set forth in claim 9, wherein act (a) comprises the act of:

reading color palette index values of a frame buffer of the video graphics controller; and

using the color palette index values to index the VGA shadow look up table to obtain the color values for pixels in the frame buffer.

12. The method, as set forth in claim 9, wherein acts (a) and (b) are performed in the recited order.

13. A method of implementing color graphics on a remote computer, the method comprising the acts of:

(a) snooping processor accesses to an EGA color palette of a video graphics controller and storing EGA color palette information from the processor in an EGA shadow look up table of a remote management controller;

(b) snooping processor accesses to a VGA color palette of the video graphics controller and storing VGA color palette information from the processor in a VGA shadow look up table of the remote management controller; and

(c) using the EGA and VGA color palette information stored in the respective EGA and VGA shadow look up tables to transmit color information to the remote computer.

14. The method, as set forth in claim 13, wherein acts (a) and (b) comprise the act of:

snooping a bus for the processor accesses, where the bus couples the processor to the video graphics controller.

15. The method, as set forth in claim 13, wherein acts (a) and (b) comprise the acts of

reading color palette index values of a frame buffer of the video graphics controller;

and

using the color palette index values to index the shadow look up tables to obtain the color values for pixels in the frame buffer.

16. The method, as set forth in claim 13, wherein acts (a), (b), and (c) are performed in the recited order.

17. A method of implementing color graphics on a remote computer, the method comprising the acts of:

(a) snooping processor accesses to an EGA color palette of a video graphics controller and storing EGA color palette information from the processor in an EGA shadow look up table of a remote management controller; and

(b) using the EGA color palette information stored in the EGA shadow look up table to transmit color information to the remote computer.

18. The method, as set forth in claim 17, wherein act (a) comprises the act of:

snooping a bus for the processor accesses, where the bus couples the processor to the video graphics controller.

19. The method, as set forth in claim 17, wherein act (a) comprises the act of:

reading color palette index values of a frame buffer of the video graphics controller; and

using the color palette index values to index the EGA shadow look up table to obtain the color values for pixels in the frame buffer.

20. The method, as set forth in claim 17, wherein acts (a) and (b) are performed in the recited order.

21. A method of implementing color graphics on a remote computer, the method comprising the acts of:

(a) snooping processor accesses to a VGA color palette of a video graphics controller and storing VGA color palette information from the processor in a VGA shadow look up table of a remote management controller; and

(b) using the VGA color palette information stored in the VGA shadow look up table to transmit color information to the remote computer.

22. The method, as set forth in claim 21, wherein act (a) comprises the act of:

snooping a bus for the processor accesses, where the bus couples the processor to the video graphics controller.

23. The method, as set forth in claim 21, wherein act (a) comprises the act of:

reading color palette index values of a frame buffer of the video graphics controller; and

using the color palette index values to index the VGA shadow look up table to obtain the color values for pixels in the frame buffer.

24. The method, as set forth in claim 21, wherein acts (a) and (b) are performed in the recited order.