Virtual network for personal computers

• US 5,142,624 A
• Filed: 11/08/1989
• Issued: 08/25/1992
• Est. Priority Date: 11/08/1989
• Status: Expired due to Term

• Current Assignee: Qordis Cordless Technologies, LLC
• Original Assignee: Softworx, Inc.
• Inventors: Patrick, Claude B. II
• Primary Examiner(s): Heckler, Thomas M.
• Application Number:
  US07/434,015
• Time in Patent Office: 1,021 Days
• Field of Search: 364/200 MS File, 364/900 MS File, 395/200, 395/325
• US Class Current: 709/226
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: H04L 12/44 Star or tree networks

Abstract

A network for personal computers includes a network arbiter (10) disposed centrally with respect to a plurality of network stations (12), (14), (16), and (18). Each of the network stations (12-18) includes a personal computer (20), a network peripheral (24) and an interface (22). Each of the interfaces (22) interfaces with the arbiter (10) through a communication link. Each of the network stations has associated therewith a network program (82) that is operable to be executed by a central processing unit (56) in the background to an application program (80). Each of the network programs (82) has associated therewith at the network station a network status memory (86). When information is generated that is to be sent to a network peripheral, an interrupt program (92) interrupts output data from the application program (80) and controls the central processing unit (56) to output the data on a line (94) to the network interface (22). This data is then routed to the arbiter (10) along the line (98).

Claims

1. A network for interfacing a plurality of personal computers, each disposed on a separate network node, each of the personal computers having a central processing unit operable to execute application programs and an operating system for allowing the central processing unit to interface with a use and input/output devices, the network comprising:

a plurality of network peripheral devices each disposed at one of the network nodes and associated with a personal computer at that node;

an arbiter having a plurality of node ports, each node port associated with one of the network nodes, said arbiter operable to asynchronously receive network data having destination information associated therewith defining the network peripheral device and associated network node to which the received network data is to be transmitted to, and said arbiter asynchronously transmitting the received network data to the one of the network nodes associated with the destination information;

a data link disposed between each of said network nodes and said associated node port on said arbiter;

interface means associated with each of the network nodes for interfacing between each of the network nodes, said associated data link and said arbiter, said interface means including;

a network status storage medium for storing status information for the network defining at which of the network nodes each of said peripheral devices is disposed,

an input/output instruction set for being executed by the associated central processing unit and defining the one of the network peripheral devices that is to be accessed by the application program during the operation thereof, said network peripheral devices defined in accordance with information stored in said network status storage medium,

a set of network instructions for being executed by the associated central processing unit in parallel with the application program, the network instructions when executed by the associated central processing unit causing output data from the associated central processing unit running the application program to be converted to network data for routing to the defined one of said network peripheral devices through said arbiter when the defined one of said network peripheral devices is not local to the associated network node, and for causing network data received from said arbiter through said associated data link to be routed to the associated one of the network peripheral devices, and

a connecting device for allowing the associated central processing unit to transfer network data to said associated data link and receive network data from said associated data link.

2. The network of claim 1 wherein said connecting device and said data link comprise:

a serial data line for carrying serial data;

a clock line for carrying clock information to said arbiter, said arbiter utilizing said clock information to clock data into a buffer, each of the network ports having a buffer associated therewith for storing data received from said serial data line; and

power supply lines for carrying power supply voltages to said arbiter for powering said arbiter, said arbiter requiring an external power supply.

3. The network of claim 2 wherein each of the personal computers includes a parallel output port for interfacing with one of the associated peripheral devices in a parallel line, and said connecting device includes:

an adapter for being inserted between said parallel port and said associated peripheral device and in series with said parallel line;

said adapter interfacing select ones of the individual lines in the parallel port to said data line, said clock line and said power supply lines wherein the associated central processing unit accesses said serial data line, said clock line and said power supply line in accordance with said set of network instructions.

4. The network of claim 3 wherein said data line is interfaced with peripheral control lines output by the associated one of the personal computers wherein the associated central processing unit accesses the peripheral control lines to the peripheral device to output data and receive data from said arbiter.

5. The method of claim 1 wherein said network status storage medium further comprises means for updating the information stored in said network status storage medium.

6. The network of claim 5 wherein said interface means further includes means for sending network data to each of the network nodes to request status information therefrom and for receiving the request of status information, said interface means also includes means for receiving a status request and forwarding status information to the network.

7. The network of claim 1 wherein said arbiter includes a buffer associated with each of said node ports, said buffer operable to receive and store information therein, wherein the data transfer is not in real time.

8. The arbiter of claim 1 wherein said data link transfers network data in a serial format and said arbiter is operable to transmit information in packets of serial data, each packet comprising portions of a data transaction from one of the network nodes to another of the network nodes.

9. The network of claim 1 wherein said arbiter is operable to route network data from one of the network nodes to another of the network nodes at the same time it is routing data to the one of the network nodes.

10. The network of claim 1 wherein one of the network nodes can have at least two network peripheral devices associated therewith and said arbiter is operable to route information to both of the network peripheral devices on the one network node at the same time.

11. A method for networking personal computers, comprising:

providing a plurality of personal computers, each of the personal computers disposed at a remote network node and having a unique identification code associated therewith, each PC having a central processing unit for executing sets of instructions in an application program, and an operating system for interfacing the central processing unit with a user and peripheral devices that are disposed local to the network nodes;

disposing a plurality of network peripheral devices at select ones of the network nodes;

storing network status information at each of the network nodes, the status information comprising a unique identification code of each of the network nodes, the location of each of the peripheral devices in the network and network routing information;

accessing a select one of the network peripheral devices for transfer of network data thereto by a step of transferring network data between two of the network nodes only when the select one of the network peripheral devices is not disposed at the network node from which network data is to be transferred from;

accessing a selected one of the network peripheral devices through the operating system of the personal computer at the associated network node when the select one of the peripheral devices is disposed at the associated network node, the step of transferring network data comprising;

determining from the network status information at the transferring network node from which network data is to be transferred if the selected peripheral device is disposed at a different network node;

providing a communication link between all of the network nodes such that data can be simultaneously transferred between all of the network nodes, the step of providing a communication link including;

providing a centrally disposed arbiter having a plurality of network ports,

providing a single data link from each of the network ports in the arbiter to each of the personal computers,

interfacing with the associated communication link between the arbiter and the personal computer when network data is to be transferred from the network node, and asynchronously transferring and buffering the network data to be transferred at the arbiter,

determining from the routing information associated with the received and buffered data which of the network ports the received and buffered network data is to be transferred to as a destination network port and transferring the received and buffered network data to the destination network port, and

asynchronously receiving at the network node the buffered network data from the arbiter on the associated communication link when data is to be received by the network node;

assembling data from the central processing unit at the transferring network node as network data when it is determined that the peripheral device to which data is to be sent is not local in accordance with the network status and routing information, and transmitting the network data to the communication link, the network data including associated routing information,

receiving the network data from the communication link at the one of the network nodes designated as a receiving network node by the network data, and

outputting the received network data to the designated peripheral device at the receiving one of the network nodes,

the step of assembling and transferring network data operating in parallel with the processing in the central processing unit at the associated network node.