Method and apparatus for configuring plural multimedia audio cards as a local area network

• US 5,519,641 A
• Filed: 05/20/1994
• Issued: 05/21/1996
• Est. Priority Date: 05/20/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Beers, Gregory E., Brewer, James A., Stafford, James M., Habermehl, Paul R.
• Primary Examiner(s): Ramirez, Ellis B.
• Assistant Examiner(s): Assouad, Patrick J.
• Application Number:
  US08/246,452
• Time in Patent Office: 732 Days
• Field of Search: 364/514 A, 364/514 B, 364/514 C, 364/514 R, 364/242.94, 364/242.95, 364/940.62, 364/942.4, 370/85.1, 375/222
• US Class Current: 709/208
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling

Abstract

A system and method makes use of the line-in, line-out connectors for each right and left stereo channel of an audio card to provide a communications network. The distributed computers are connected in a master/slave configuration. All of the slave systems have the line-in ports, and the line-out ports, connected together. The master system line-out is connected to each slave system line-in port, and the slave system line-out ports are connected to the master line-in port, for each channel. A communications protocol is provided wherein the master system allows audio and data information to be simultaneously transferred between the master and slave systems. The master provides a clock signal and performs arbitration in order to facilitate the information transfer.

Claims

1. A computer network including a master system having a first audio card and multiple slave systems each having substantially identical second audio cards, comprising:

means for commonly interconnecting first and second substantially identical analog format audio channels on said first audio card with respective first and second substantially identical analog format audio channels of said second audio cards in the multiple slave systems;

communication means for controlling the transfer of audio and data information between said master system and said slave systems using said first audio channel to communicate control information and said second audio channel to communicate said audio and data information; and

means for simultaneously processing said audio and data information in said first and second audio cards.

2. A system according to claim 1 wherein said communication means comprises means, within said master system for outputting a clock signal to said multiple slave systems.

3. A system according to claim 2 wherein said communication means further comprises:

means, within said slave systems, for receiving said clock signal from said master system; and

means, within said slave systems, for outputting said clock signal to said master to maintain a steady state condition.

4. A system according to claim 3 wherein said communication means further comprises means, within said slave systems, for withholding the output of said clock signal to said master to request access to said network.

5. A system according to claim 4 wherein said communication means further comprises:

means, within said master for determining which of said slave systems has requested access to said network; and

means, within said master for granting access to said network to the requesting slave system.

6. A system according to claim 5 wherein said communication means further comprises means, within said requesting slave system for transferring data to either said master system or another one of said slave systems.

7. A system according to claim 6 wherein said communication means further comprises means, within said master for transferring data to said requesting slave system.

8. A system according to claim 7 wherein said communication means further comprises:

means, within said master, for revoking access to said network by said requesting slave system; and

means for granting access to another of said slave systems requesting access to said network.

9. A system according to claim 8 wherein said means for simultaneously processing comprises a multitasking central processing system included on each of said audio cards.

10. A method of communicating audio information and data information between a master computer system having a first audio card and multiple slave computer systems each having substantially identical second audio cards, comprising the steps of:

commonly interconnecting first and second substantially identical analog format audio channels on said first audio card with respective first and second substantially identical analog format audio channels of said second audio cards in the multiple slave systems;

controlling the transfer of audio and data information between said master system and said slave systems using said first audio channel to communicate control information and said second audio channel to communicate said audio and data information; and

simultaneously processing said audio and data information in said first and second audio cards.

11. A method according to claim 10 wherein said step of controlling comprises the step of outputting, by said master system, a clock signal to said multiple slave systems.

12. A method according to claim 11, wherein said step of controlling further comprises the steps of:

receiving, by said slave systems, said clock signal from said master system; and

outputting, by said slave systems, said clock signal to said master to maintain a steady state condition.

13. A method according to claim 12 said step of controlling further comprises the step of withholding, by said slave systems, the output of said clock signal to said master to request access to said network.

14. A method according to claim 13 wherein said step of controlling further comprises the steps of:

determining, by said master, which of said slave systems has requested access to said network; and

granting, by said master, access to said network to the resting slave system.

15. A method according to claim 14 wherein said step of controlling further comprises the step of transferring, by said requesting slave system, data to either said master system or another one of said slave systems.

16. A method according to claim 15 (wherein said step of controlling further comprises the step of transferring, by said master, data to said requesting slave system.

17. A method according to claim 16 wherein said step of controlling further comprises the steps of:

revoking, by said master, access to said network by said requesting slave system; and

granting access to another of said slave systems requesting access to said network.