Automated auction protocol processor

Abstract

A data processing system for implementing transaction management of auction-based trading for specialized items such as fixed income instruments. The data processing system provides a highly structured trading protocol implemented through a sequence of trading paradigms. The system employs a distributed computer processing network linking together a plurality of commonly programmed controlled workstations. The protocol and its programmed controlling logic enhances trading efficiency, rewards market makers and fairly distributes market opportunity to system users.

Claims

What is claimed is:

1. A method implemented by a programmed computer system for trading a volume of an item between participants, comprising:

providing a bid/offer system state to enable participants to enter into the system bids and offers at select prices and volumes for the item;

presenting the bids and offers to the participants;

receiving a first hit or lift trade command from a first participant, responding to presented bids and offers, to transact a trade of a desired volume of the item at a desired price;

in response to the first trade command, transitioning from the bid/offer system state to a trading system state to transact a trade of the item at a defined price corresponding to the desired price, and to transact in response to an additional trade command a trade of an additional volume of the item at the defined price; and

if a bid or offer hit or lifted by the first trade command has not aged, transitioning to a second look system state to enable the first participant to refuse to trade at least a portion of the volume of the item associated with the unaged bid or offer.

2. The method of claim 1, wherein the desired volume is all bid or offered volume.

3. The method of claim 1, wherein the first participant is enabled to refuse to trade the entire volume associated with the unaged bid or offer.

4. The method of claim 1, wherein if the first participant refuses to trade a portion of the entire volume associated with the unaged bid or offer, enabling a second participant to enter a second hit or lift trade command to trade the portion at the defined price.

5. The method of claim 1, wherein a bid or offer is not aged if it had been entered into the system within a given period of time prior to receipt of the trade command.

6. The method of claim 5, wherein the given period of time is about 2 seconds.

7. The method of claim 1, wherein a bid or offer is not aged if it increased the total volume of the item that was hit or lifted within a given period of time prior to receipt of the trade command.

8. A method implemented by a programmed computer system for trading a volume of an item between participants, comprising:

providing a bid/offer system state to enable participants to enter into the system bids and offers at select prices and volumes for the item;

presenting the bids and offers to the participants;

receiving a first hit or lift trade command from a first participant, responding to presented bids and offers, to transact a trade of a desired volume of the item at a desired price;

in response to the first trade command, transitioning from the bid/offer system state to a trading system state to transact a trade of the item at a price defined by the desired price, and to transact in response to an additional trade command a trade of an additional volume of the item at the defined price; and

determining that the first participant may not have intended to trade the entire volume that was hit or lifted by the trade command, and responsively entering a second look system state enabling the first participant to refuse to trade at least a portion of the volume of the item that the first participant may not have intended to trade.

9. The method of claim 8, wherein the desired volume is all bid or offered volume.

10. The method of claim 8, wherein the first participant is enabled to refuse to trade the entire volume of the item that the first participant may not have intended to trade.

11. The method of claim 8, wherein if the first participant refuses to trade a portion of the volume of the item that the first participant may not have intended to trade, enabling a second participant to trade the refused volume at the defined price.

12. The method of claim 8, wherein said determining step determines that the first participant may not have intended to trade the entire volume if a bid or offer hit or lifted by the first trade command has not aged.

13. The method of claim 8, wherein said determining step determines that the first participant may not have intended to trade the entire volume that was hit or lifted if that volume had been increased by a bid or offer within a given period of time prior to receipt of the hit or lift.

14. A method implemented by a programmed computer for trading a volume of an item between participants using a system of networked workstations, comprising:

providing a bid/offer system state wherein passive participants enters bids or offers for the item at associated select prices and volumes, and an active participant hits or lifts one or more entered bids or offers to trade a desired volume of the item at a desired price;

determining whether a bid or offer that was hit or lifted had aged;

if the bid or offer had aged, executing a trade of the associated volume of the item at the desired price; and

if the bid or offer had not aged, providing a second look system state that allows the active participant to decide whether or not to trade the volume of the item associated with the unaged bid or offer.

15. The method of claim 14, wherein a bid or offer is not aged if it was received within a given period of time prior to being hit or lifted.

16. The method of claim 15, wherein the given period of time is about 2 seconds.

17. The method of claim 14, wherein a bid or offer is not aged if it caused the total volume of bids or offers that was hit or lifted by the active participant to be increased within a given period of time prior to the bid or offer being hit or lifted.

18. The method of claim 14, wherein the active participant in the second look state may refuse to trade all or a portion of the volume of the item associated with the unaged bid or offer.

19. The method of claim 14, wherein the hit or lift entered by the active participant is a command to hit or lift all of the volume bid or offered by the passive participants.

20. A method implemented on a distributed workstation computer system for trading an item between passive participants and an aggressor participant, the method comprising:

providing a bid/offer system state wherein the passive participants participate by entering bids or offers at select prices and volumes for the item;

distributing the bids or offers to the workstations;

receiving a hit or lift from the aggressor participant in response to one or more of the bids or offers to trade a desired volume of the item at a desired price; and

transitioning to a trading system state wherein:

(a) a trade transaction is executed, at a defined price set by the hit or lift, between the aggressor participant and each passive participant whose bid or offer had been hit or lifted by the aggressor participant;

(b) a period of exclusivity is provided during which the aggressor participant and a designated passive participant may control trading by transacting additional volume of the item with each other at the defined price to the exclusion of other participants desiring to participate in trading; and

(c) upon termination of the period of exclusivity, new trade transactions involving the other participants are tested for and executed at the defined price without providing the other participants a period of exclusivity to control trading.

21. The method of claim 20, wherein said designated passive participant is the first passive participant to have entered a bid or offer that was hit or lifted.

22. A method implemented on a distributed-workstation computer system for trading an item between participants, said method comprising:

providing a bid/offer system state wherein a first participant enters a bid or offer for the item at a select price and volume;

receiving from a second participant a trade command to hit or lift the bid or offer;

entering a trading system state wherein a trade transaction is executed between the first and second participants for a volume of the item at a defined price, and wherein (a) the first and second participants are provided a period to control trading, during which they may transact with each other additional volume of the item at the defined price to the exclusion of other participants desiring to participate in the trade, and (b) upon conclusion of the period, a new trade transaction is automatically executed at the defined price in response to a trade command entered by another participant without providing the other participant a period to control the trade.

23. The method of claim 22, wherein the trade command entered by the other participant is entered during the period to control trading but not executed until the conclusion of said period.

24. A method implemented on a distributed-workstation computer system for trading an item between participants, said method comprising:

providing a bid/offer system state wherein a first participant enters a bid or offer for the item at a select price and volume;

receiving from a second participant a trade command to hit or lift the bid or offer;

entering a trading system state wherein a trade transaction is executed between the first and second participants for a volume of the item at a defined price, and wherein (a) the first and second participants are provided a period to control trading, during which they may transact with each other additional volume of the item at the defined price to the exclusion of other participants desiring to participate in the trade, and (b) upon conclusion of the period, new transactions are automatically executed at the defined price in response to a plurality of trade commands entered by other participants without providing the other participants a period to control the trade.

25. The method of claim 24, wherein the plurality of trade commands are entered during the period to control trading but not executed until the conclusion of said period.

26. A system for transacting the purchase and sale of a select item between participants, the system comprising:

a first workstation that receives from a first participant a bid or offer at a select price and volume for the item;

a second workstation that receives from a second participant a hit or lift of the bid or offer; and

a central server that is coupled to the workstations for communication to the server of the bid or offer and hit or lift, and that transitions between a plurality of states which define the ability of participants to participate in trading, wherein the plurality of states includes a first state enabling the bid or offer to be received, and a second state entered in response to the hit or lift being received within a given time period of the bid or offer, said second state enabling the second participant to refuse the sale or purchase of at least a portion of the volume of the item that was hit or lifted.

27. The system of claim 26, wherein one of the first and second participants is a broker, and the other of the first and second participants is a customer.

28. The system of claim 26, further comprising:

a communication server coupled to the central server and to a remote communications link; and

a remote server located remotely from the communication server and coupled to the communication server via the remote communications link; wherein:

said first workstation is one of a plurality of first workstations located locally to the central server and coupled to the central server via a local network, each of said first workstations operated by a broker participant; and

said second workstation is remotely located from said central server and coupled to said central server via a remote communications link, and operated by a customer participant.

29. A system for trading an item between an aggressor participant and one or more passive participants, comprising:

a first workstation that receives bids or offers from the passive participants for the item at select prices and volumes;

a second workstation that receives a trade command from the aggressor participant to hit or lift one or more of the bids or offers in order to sell or buy a desired volume of the item at a desired price; and

a programmed computer, coupled to the workstations, that (1) provides a system bid/offer state enabling the passive participants to participate by entering bids or offers with respect to the item and that, in response to a hit or lift of one or more of the entered bids or offers, and (2) transitions to a system trading state which (a) executes a trade transaction in accordance with the hit or lift at a defined price set by the hit or lift, (b) provides a period of exclusivity enabling the aggressor participant and a designated passive participant to control subsequent trading by executing transactions between the aggressor and designated passive participant of additional volume of the item at the defined price to the exclusion of other participants desiring to participate in the trading, and (c) upon termination of the period of exclusivity, executes new trade transactions involving the other participants at the defined price without providing the other participants a period of exclusivity to control trading.

30. The method of claim 29, wherein the other participants may enter trade commands for the new trade transactions during the period of exclusivity, and the new trade transactions are only executed, if at all, after the conclusion of said period.

31. The system of claim 29, wherein said programmed computer determines whether a bid or offer hit or lifted by the trade command is aged and, if the bid or offer is not aged, transitions to a second look state in which the aggressor participant is enabled to refuse the sale or purchase of at least a portion of the volume of the item associated with the unaged bid or offer.

Description

FIELD OF THE INVENTION

The present invention relates to data processing systems for assisting in financial transactions. More particularly, the present invention relates to a data processing apparatus and method for the managed trading of select classes of securities or other commodities in accordance with specific protocols in an auction format with controlled sequence of auction events. The inventive system is presented in the context of selected fixed income auction protocols for fairly and quickly transacting offer-bid trading.

BACKGROUND OF THE INVENTION

Economic activity has at its centerpiece the buyer-seller transaction for all goods and services produced and consumed in a market economy. It is the fundamental mechanism to which resources are allocated to producers and output to consumers. The operation of the buyer-seller mechanism can and often is a critical determination of economic efficiency and when operated properly, will substantially enhance market performance.

Through history, there have been many different approaches adopted to bringing buyers and sellers together, each with the key objective of permitting transactions at or as close as possible to the "market" price of the goods satisfying. By definition, the market price is the price (in given currency terms) that a fully educated market, given full access will transact select goods. Discovery of the market price can only be accomplished by permitting full access to the transaction by essentially all potential buyers and sellers and allowing expression of each party's desires. However, the buyer-seller transaction must be structured to operate at very low costs--or it will distort the market price of goods with artificially high transaction costs. Thus, the two keys to effective buyer/seller transactions--full access of expression and knowledge coupled with low transaction costs--can be and are often conflicting, necessitating trade-offs between trading efficiency and market knowledge.

One well-known and particularly successful trading system is known as the "open outcry auction". This involves a process wherein buyers and sellers collect in one location and prices for select goods are presented to the group through a broker, via simple vocal offerings. This approach has been used for almost all to kinds of goods, but is particularly useful where there are no established trading locations or markets for the selected items. It is the dominate trading forum for exotic items such as rare pieces of art and the like. Although successful in bringing interested parties to the transaction, the overall process can be very expensive, adding significantly to the market-distorting transaction costs.

Open outcry auction techniques, modified over time, have also found successful application in many trading activities, including the buying and selling of farm produce and livestock, commodities contracts, futures contracts on a variety of items and--particularly germane to the preferred embodiment of the present invention--fixed income securities. These trading activities focus on the buying and selling of essentially fungible items, that is, items that are without meaningful differentiation from like items on the market. For example, a bushel of wheat for February delivery is considered for sale and delivery at a price independent of its source. Similarly, a 30-year U.S. Treasury bond paying a coupon rate of 8 percent and having a July 1996 issue date is indistinguishable from other 30-year treasuries having the same properties. Accordingly, the price buyers are willing to pay and sellers are willing to accept defines the market price of all 30-year treasury bonds of that same vintage, allowing a source transparent application of open outcry auction trading.

The fixed income securities issued by the United States government are known as U.S. Treasuries. These instruments typically span maturities of 13 to 52 weeks (T-bills), one to ten years (notes), and up to 30 years (Bonds). T-Bills are pure discount securities having no coupons. Almost all other Treasuries having longer terms are coupon notes or bonds, with a defined interest payment cycle of semi-annual payments to the holder. An additional and more recent type of Treasury.

Treasuries have characteristic properties that make them especially useful for the purpose of the present invention and, therefore, are used exclusively in the following discussions with the fundamental tenant that the principles may be applied to other types of fixed income securities without departing from the inventive concepts. One important attribute of treasuries, in the context of the present invention, is the minimal and uniform default risk; the issuance of U.S. government paper removes the default risk as a defining criteria in the relative pricing of treasuries in the market place when they are backed by the full faith and credit of the U.S. government.

New Treasury securities are auctioned by the U.S. government at preestablished auction dates. The auction prices for newly issued Treasuries having a face value with a set coupon rate defines the Treasuries' yields when issued. After the auction, the Treasuries enter the secondary market and are traded typically "over the counter," i.e., without a defined exchange. As inflation expectations and supply and demand conditions change, the prices of recently auctioned Treasuries fluctuate on the secondary market. The new prices are reflected by competing bid and offer prices communicated among institutions, banks, brokers, and dealers in the secondary market. For example, the yield of a treasury note increases as its price drops in the market, typically reflecting an overall increase in the interest rates for that term of security.

The newly auctioned securities are traded with and in conjunction with the securities issued in earlier auctions. In this context, some securities are traded more often than others and are called the "actives"; the actives usually correspond to the recently issued securities as opposed to the older securities in the market. Indeed, some older securities are infrequently traded, creating an illiquid market that may or may not reflect the current market-determined interest rate for that maturity length security.

Accordingly, the very size and diversity of the treasury market requires a high level of sophistication by market participants in the bidding, offering, buying, and selling transactions involving these securities. The very complexity associated with the transaction and the scale of trading undertaken by banks, brokers, dealers, and institutional participants necessitates a rigidly structured approach to trading.

In the past, open outcry auction bond brokering has served its customers well, providing highly efficient executions at near perfect market pricing. The open outcry auction applied to bond trading was implemented by a broker working with a collection of customers to create and manage a market. Typical customer representatives--both buyers and sellers--at a common location (e.g., a single room) where the representatives of the customers would communicate with each other to develop pricing and confirm transactions. This process employed the expression by the representatives of various bid and offer prices for the fixed income security at select volumes (i.e., how many million dollars of bonds at a given maturity). This expression would involve the loud oral "cry" of a customer-proposed bid or offer and the coordination with the fellow representatives regarding the extraction of complimentary positions--until a transaction match is made and a deal is done. This "trade capture" process relies on after-the-fact reporting of what just transpired through the oral outcry trade.

Recently, the trade capture process was performed by having designated clerks input data into electronic input devices. An input clerk would attempt to interpret the open outcry of many individual brokers simultaneously who sequentially are making verbally known their trading instructions of their customers. The quality of the data capture was a function of the interpretative skill of the input clerk, and the volume and the volatility of customer orders. A significant drawback to this type of auction data capture process is the difficulty in discerning the distinct trading instructions verbalized in rapid succession during a quickly moving market, so that an accurate sequence of data can be captured by brokers and a set of inputters.

The many permutations of this process will be discussed in detail below. At this juncture, suffice to say that, at lower volumes of transactions existing at the time of its development, and the lack of suitable alternatives, the open outcry auction process remained the dominant trading mechanism for decades. However successful, this approach was not perfect. Indeed, in recent years, some of the problems in an open outcry auction forum have been amplified by the vastly increased level of trading now undertaken in the fixed income field. Generally, difficulties would occur by the injection of trader personalities into the open outcry auction process. For example, a loud, highly vocal representative may in fact dominate trading--and transaction flow--even though the representative may only represent a smaller and less critical collection of customers. Although such aggressive actions at open outcry auction may be beneficial to those particular customers in the short run, overall, such dominance of the trading can and will distort pricing away from the actual market conditions.

Other problems exist in open outcry auction that deplete efficient trading. The speed at which trading flows and the oral nature of the auction process injects a potential for human error that often translates into many millions of dollars committed to trades unrelated to customer objectives. As such, the broker is left at the end of each trading day with a reconciliation process that may, under certain market conditions, wipe out all associated profit from that day's trading. Also, customers may quickly change direction regarding trading, based on new information available to the market. Shifting position or backing out of previously committed transactions on very short notice is often very difficult in the traditional open outcry auction process.

There have been many past efforts to incorporate computers into trading support for select applications and securities. Indeed, almost all trading today involves some computer support, from simple information delivery to sophisticated trading systems that automate transactions at select criteria. However, these systems have not significantly impacted the issues presented above as they relate to open outcry auction trading in the fixed income field. It was with this understanding of the problems with certain trading processes that formed the impetus for the present invention.

OBJECTS AND SUMMARY OF THE PRESENT INVENTION

It is, therefore, an object of the present invention to provide a data processing system to implement a trading system capable of high volume trading activity.

It is another object of the present invention to provide a data processing method supporting a transaction enabling process for trading securities at accelerated levels with few errors and low costs.

It is yet another object of the present invention to provide a data processing system to support a formalized trading protocol governing the control of trading on a bid/offer market.

It is also an object of the present invention to provide a system for collecting, displaying and distributing in real time information on current market activity in fixed income securities and processing this information to quantify the extent of order and trading activity of customers in real time.

It is another object of the present invention to provide an apparatus for the select processing of several types of data wherein data is qualified prior to use, and for translating the qualified data into order and trading states for fixed income securities.

It is still another object of the present invention to provide a data processing system that provides controlled access to trading commands pursuant to preestablished trading criteria.

It is yet another object of this invention to provide a computer system that includes multiple workstations linked by high speed communication paths to permit rapid distribution and exchange of market data to participants.

It is still another object of the present invention to provide a system that rewards customers that create liquidity while insuring customer orders are satisfied in an orderly and equitable fashion.

It is yet another object of the present invention to provide a database system linked to the auction processor for collecting, filtering, and distributing select market data in near real time.

It is another object of the present invention to provide a computer system with a dedicated input system for a workstation, that is customized for the trading undertaken by that workstation and may be customized to the trading patterns and customers for a given broker at that workstation.

Yet another object of this invention is to provide timely order checkout.

Still another object of this invention is to provide customized trading tools particular to a given customer, such as stop limit orders, contingent orders, flags (warnings) to the broker that a particular customer has reached a trading limit (e.g., margin limit), and the like.

A further object of this invention is to utilize the present system for the trading of other financial products, such as futures, indices, and the like.

The above and other objects of the invention are provided by a computer-based, data processing system having program controlled logic for managing select trading. The data processing system employs a plurality of trading workstations linked with a server for coordinated data flow and processing. Communication is provided by a network, such as, for example, an Ethernet, token ring, token bus, or other hierarchical LAN and/or WAN configuration. The system preferably includes a dedicated keypad for input at each workstation that provides individually programmed keystroke commands; alternatively, other keyboards, keypads or voice controlled electronic devices can be used with the present system. Central processing logic dictates the available order, trading and allocation options, and screen displays for each workstation. As orders and transactions are entered, various protocols affect the allocation of bid-offer control, priority generation, exclusive trading time, and interactive trade management. As trades are completed, the system updates a linked database with newly entered transactional data.

In accordance with the present invention, the controlling logic provides a sequence of trading states for each participant. The five states are:

               TABLE 1
                 (i)               Workup State
                 (ii)              Bid-Offer State
                (iii)              Second Look State
                 (iv)              When State
                 (v)               Workdown State

    TABLE 2
    Bid         Dollar amount offered to buy a security - issue.
    Offer       Dollar amount offered to sell a security - issue.
    Spread      Difference between best bid(s) and offer(s) on market.
    Issue       A common class of fixed rate treasuries.
    Hit         Accepting a pending bid.
    Lift        Accepting a pending offer.
    Size        The volume in dollars of a particular Bid/Offer.
    Makers      Customers with pending offers and bids - making a market.
    Uncleared   A bid or offer that cannot be traded for a given
    Entry       time by certain participants.
    Traders     After a trade is initiated, all customers involved in transac-
                tions (as buyer or seller).
    Trade       A string of transactions at one price initiated by a hit or
     lift
                and continuing until timed out or done.
    Aggressor   A customer who initializes a trade.
    Active Side Group of Makers on same side of market as the Aggressor
    Passive     Group of customers on opposite side of market from the
    Side        Aggressor.

                              QUAD 1
        100.01                2      100.03               15
        CUST        Bid      Bot      Cust      Offer    Sold
        2001         1        0       2007        5        0
        2002         1        0       2006       10        0
        TOTL         2        0                  15        0

                              Quad 2
        >7.625 225            TZ
        108.04                 27     *108.04+             10
        Cust           Bid     Bot      Cust      Offer   SOLD
        3001            5       0       3007       10       0
        3002            1       0
        3003            1       0
        3001           20       0
        TOTL           27       0                  10       0

                             QUAD 3A
        >7.625 225            TZ
        108.04                 20     *108.04+              1
        Cust           Bid     Bot      Cust      Offer   SOLD
        3002           10       0       3007        1       0
        3003           10       0
        TOTL           20       0                   1       0
                             QUAD 3B
        >7.625 225            TZ
        108.04                 20     108.04+    WTAK       1
        Cust           Bid     BOT     Cust      Offer    SOLD
        3002            0       0      3007        1        0
        3003            0       0
        3001            1       0
        TOTL            1       0                  1        0

                             QUAD 4A
        >7.625 225            TZ
        108.04                 16     108.05+             45
        Cust           Bid     BOT     Cust     Offer    SOLD
        3001            5       0      3007      25        0
        3002            5       0      3006      10        0
        3003            1       0      3005      10        0
        3001            5       0
        TOTL           16       0                45        0

                             QUAD 4B
        >7.625 225          TZ     Refno 68119
        108.04        HIT    16      +108.05+              36
        Cust          Buy    BOT       Cust       Sell    SOLD
        3001           0     10        3005         0      16
        3002           0      3
        3003           0      1
        TOTL           0     16                     0      16

                             QUAD 4C
        >7.625 225          TZ     Refno 68119
        108.04        HIT    16       108.05+              36
        Cust          Buy    BOT       Cust       Sell    SOLD
        3001           0     10        3005         0      16
        3002           5      5        3004        50       0
        3003           0      1
        TOTL           5     16                    50      16

                             QUAD 4D
        >7.625 225          TZ     Refno 68119
        108.04        HIT    21       108.05+              36
        Cust          Buy    BOT       Cust       Sell    SOLD
        *3001          0     10        *3005        0      16
        3003           0      1        3004        45       5
        3002           0     10
        TOTL           0     21                    45      21

                             QUAD 5A
        >7.625 225          TZ
        108.04        HIT     7     Refno 68119             0
        Cust          Buy    BOT       Cust       Sell    SOLD
        3001           0      5        3007         0       7
        3002           0      1
        3003           0      1
        3004           1      0
        TOTL           1      7                     0       7

                             QUAD 5B
        >7.625 225          TZ
        108.04        HIT     8     Refno 68115             0
        Cust          Buy    BOT       Cust       Sell    SOLD
        3001           0      5        3007         2       8
        3002           0      1
        3003           0      1
        3004           0      1
        TOTL           0      8                     2       8

                             QUAD 5C
        >7.625 225          TZ
        108.04        HIT     7     Refno 68117             0
        Cust          Buy    BOT       Cust       Sell    SOLD
        3001           0      5        3007         0       7
        3002           0      1
        3003           0      1
        3004           1      0
        3005           1      0
        TOTL           1      7                     0       7

                             QUAD 6A
        >7.625 225            TZ
        108.04         HIT     15     *108.04+             25
        Cust           Bid     BOT      Cust      Offer   SOLD
        3001            5       0       3007       25       0
        3002           10       0
        TOTL           15       0                  25       0

                             QUAD 6B
        >7.625 22          TZ     Refno 68118
        108.04               11       108.04+      TAK      5
        Cust          Buy    BOT       Cust       Sell    SOLD
        *3001          0      5        3007        20       5
        TOTL           0      5                    20       5

                             QUAD 6C
        >7.625 225          TZ     Refno 68118
        108.04               11       108.04+      TAK      5
        Cust          Buy    BOT       Cust       Sell    SOLD
        *3001          0      5        3007        20       5
                                       3006        10       0
        TOTL           0      5                    20       5

• Inventors
  Fraser, Stuart A.; Lutnick, Howard; Paul, Bijoy;
• Assignee
  Cantor Fitzgerald, L.P. (CFLP) (New York, NY); CFPH L.L.C. (CFPH) (New York, NY)
• Published
  May-6-2003
• Current US Classes:
  705/35
  705/36
  705/37
• Application #
  294526
• International Classes
  G06F 017/20; G06F 017/00
• Field of Search
  705/35 705/36 705/37
• Examiner
  Myhre; James W.
• Agent
  Fish & Neave, Weiss; Joel
• US Patent References:
  3976840
  4412287
  4677552
  4903201
  5038284
  5101353
  5136501
  5168446
  5243331
  5297031
  5297032
  5305200
  5375055
  5717989
  5915209
  6014627
  6134535
  6263321