System and method for transmitting R-G-B signals in a multi-user computer system

• US 6,212,584 B1
• Filed: 10/27/1997
• Issued: 04/03/2001
• Est. Priority Date: 11/15/1996
• Status: Expired due to Fees

• Current Assignee: Maxspeed Corp. (HP Inc.)
• Original Assignee: Maxspeed Corp. (HP Inc.)
• Inventors: Nei, Chu-Ching
• Primary Examiner(s): AUVE, GLENN ALLEN
• Application Number:
  US08/958,044
• Time in Patent Office: 1,254 Days
• Field of Search: 348/6, 348/10, 348/12, 348/15, 348/17, 348/552, 455/3.1, 455/6.1, 370/490, 710/72, 710/73, 710/62, 710/64, 710/101, 710/103, 710/129, 709/200
• US Class Current: 710/72
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• CPC Class Codes: G09G 2370/24 Keyboard-Video-Mouse [KVM] switch
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

A multi-user computer system using a communications protocol in transmitting data between a plurality of user interface units is described. The system includes a base unit, which has a bus, a processor coupled to the bus, a display device coupled to the bus, an input device also coupled to the bus, and an interface controller coupled to the bus, wherein said processor controls the operation of the base unit and processes data entered into the base unit and operates to generate output data to be displayed on the display device. The system also includes an auxiliary unit, which has a protocol interface controller, a second display device coupled to the protocol interface controller, a second input device coupled to the protocol interface controller, wherein the protocol interface controller controls the operation of the auxiliary unit and interface with the base unit in accordance with a predetermined communications protocol. The system further includes a communications cable, which has a plurality of unshielded twisted-pair conductors coupled to the interface controller and the protocol interface controller for transmitting signals between said base unit and said auxiliary unit, wherein the signals to be transmitted includes data and red-green-blue (RGB) video signals, said base unit receives input data from said auxiliary unit via said communications cable and operates to generate output data to be displayed on the second display device of said auxiliary unit and transmits the output data via said communications in accordance with the predetermined communications protocol.

Claims

1. A multi-user computer system comprising:

a base unit including a processor, and an interface controller coupled for communication with said processor;

an auxiliary unit including a first bus, an auxiliary display device coupled to said bus, at least one input device coupled to said bus, and an interface protocol controller coupled to said bus, said auxiliary unit being operative to develop input data signals in response to input received via said input device; and

a communications cable coupled to provide communication between said interface controller and said protocol controller, said cable including a plurality of unshielded twisted-pair conductors for carrying analog red, green, and blue video signals (RGB signals) and horizontal and vertical sync signals to said auxiliary unit and for carrying data signals, including input data signals, between the base and auxiliary unit, said data signals being encoded with said horizontal and vertical sync signals, said RGB signals and horizontal and vertical sync signals providing for display of information on said auxiliary display device.

2. The multi-user computer system of claim 1, wherein:

said interface controller and said protocol interface controller each include an RJ-45 jack; and

said communications cable includes two RJ-45 connectors, each being coupled to a corresponding end of said cable, said connectors being provided for coupling said cable with said jacks.

3. The multi-user computer system of claim 1, wherein said communications cable further comprises:

a first connector and a second connector each having eight connector pins;

a first twisted pair of conductors coupling first and second pins of said first connector to corresponding first and second pins of said second connector;

a second twisted pair of conductors coupling third and sixth pins of said first connector to corresponding third and sixth pins of said second connector;

a third twisted pair of conductors coupling fourth and fifth pins of said first connector to corresponding fourth and fifth pins of said second connector;

a fourth twisted pair of conductors coupling seventh and eighth pins of said first connector to corresponding seventh and eighth pins of said second connector;

said first, third, and fourth pins of said first conductor providing for transmission of red, green, and blue analog-out video signals respectively;

said second and fifth pins of said first conductor providing for transmission of red and blue analog-return video signals respectively;

said sixth pin of said first conductor providing an AC ground reference and DC power to said auxiliary unit;

said seventh pin of said first conductor providing for transmission of data and horizontal and vertical sync signals between said base unit and auxiliary unit; and

said eighth pin of said first conductor providing a DC ground reference for said auxiliary unit.

4. The multi-user computer system of claim 1, wherein said input device includes a keyboard.

5. The multi-user computer system of claim 1, wherein said input device includes a pointing device.

6. The multi-user computer system of claim 5, wherein said pointing device is a mouse.

7. The multi-user computer system of claim 1, wherein said interface controller is an interface module coupled to said processor via a bus.

8. The multi-user computer system of claim 1, wherein said base unit further comprises a memory unit and wherein said interface controller is directly coupled to said processor and said memory unit.

9. The multi-user computer system of claim 1, wherein said base unit and said auxiliary unit communicate via said cable in accordance with a protocol wherein:

during a first time period, said base unit is operative to transmit a first signal indicating the beginning of transmission of a serial stream, and is also operative to transmit data in said serial stream one bit at a time separated by a predetermined period of time until all of the data in said stream is transmitted; and

during a second time period, said auxiliary unit is operative to transmit a second signal indicating the beginning of transmission of a second serial stream, and is also operative to transmit data in said second serial stream one bit at a time separated by a predetermined period of time until all of said data in said second serial stream has been transmitted.

10. The multi-user computer system of claim 9, wherein, during a third time period, said base unit is operative to transmit a third signal indicating the beginning of transmission of a third serial stream, and is also operative to transmit data in said third serial stream one bit at a time separated by a predetermined period of time until all of the data in said third stream is transmitted, said third stream including audio signals.

11. The multi-user computer system of claim 10, wherein said third signal comprises a second plurality of signals, said second plurality of signals including a plurality of audio signals.

12. The multi-user computer system of claim 9, wherein during a third time period, occurring between said first time period and said second time period, said base unit and said auxiliary unit both relinquish control over said cable.

13. A method of providing an auxiliary computer user interface via an auxiliary unit coupled to communicate with a base computer including a processor, and an interface controller coupled to said processor, the auxiliary unit including a bus, an auxiliary display device coupled to said bus, at least one auxiliary input device coupled to said bus, and an interface protocol controller coupled to said bus, said protocol controller being coupled with said interface controller via a communications cable, said method comprising the steps of:

developing input data signals at said auxiliary unit in response to input received via said input device;

transmitting said input data signals from said auxiliary unit to said base computer via said cable;

developing analog red, green, and blue video signals (RGB signals) at said base computer in response to said input data signals;

transmitting said RGB signals from said base computer to said auxiliary unit via said cable; and

displaying information on said auxiliary display device in response to said RGB signals.

14. A method of providing an auxiliary computer user interface as recited in claim 13, further comprising the step of

transmitting horizontal sync signals and vertical sync signals from said base computer to said auxiliary unit via said cable, said horizontal sync signals and said vertical sync signals providing for control of said auxiliary display device.

15. A method of providing an auxiliary computer user interface as recited in claim 13, wherein said step of transmitting said input data signals from said auxiliary unit to said base computer includes, during a first time period:

transmitting a signal indicating the beginning of transmission of a serial stream, and

transmitting input data in said serial stream one bit at a time separated by a predetermined period of time until all of said data in said serial stream has been transmitted.

16. A method of providing an auxiliary computer user interface as recited in claim 15,

wherein said auxiliary further includes a speaker;

and

wherein said method further comprises the steps of;

transmitting audio signals from said base computer to said auxiliary unit during a second time period, said step of transmitting audio signals including;

transmitting a first signal from said base computer to said auxiliary unit, said first signal indicating the beginning of transmission of a serial stream, and

transmitting audio data in said serial stream one bit at a time separated by a predetermined period of time until all of the data in said stream is transmitted; and

generating sounds using said speaker in response to said audio signals.

17. A computer system having a remote user station, the system comprising:

a base unit including a processor and an interface controller coupled for communication with said processor;

an auxiliary unit including an auxiliary display device, at least one input device, and an interface protocol controller for sending to and receiving information from the base unit, the information received for display on the auxiliary display device, and the information sent derived from the at least one input device; and

a communications cable coupled to provide communication between said interface controller and said protocol controller, said cable including a plurality of unshielded twisted-pair conductors for carrying analog red, green, and blue video signals (RGB signals) and horizontal and vertical sync signals to said auxiliary unit and for carrying data signals, including input data signals, between the base and auxiliary unit, said data signals being encoded with said horizontal and vertical sync signals, said RGB signals and horizontal and vertical sync signals providing for display of information on said auxiliary display device.