IMPROVED TELECOMMUNICATION DISPLAY SYSTEM

Abstract: Existing voice telephone communications are augmented in a simple and understandable way by the addition of a "dumb" display terminal (14) at a subscriber's location (10). Text, graphics, and picture data can be transmitted in ASCII code or other protocol, over existing, standard telephone lines (52, 54) and displayed on the terminal (14). The "dumb" feature is due to the display terminal (14) having a voice/data selector that can automatically recognize digital data and switch from voice communication to data communication mode. Accordingly, this display terminal (14) is entirely self-contained and is controlled from a remote location (60), such as a telemarketing agents position, requiring nothing more from the subscriber than mere possession of the display terminal (14).

Description: Improved Telecommunication Display System Description Technical Field The present invention relates to telecommunications systems and more specifically to a telecommunications system adapted for transmission of speech and display data over standard, existing telephone lines for audio-graphic communication between parties. Background Art It is often desirable to be able to transmit a visual image of data being discussed by parties over a telephone line concurrent with the verbal discussion. For example, a travel agent might wish to show a telephone customer a travel itinerary as they are discussing it, or a broker might want to show a customer a visual confirmation of a financial transaction, which the customer has just made orally over the telephone. Facsimile devices for transmitting data over telephone lines and displaying it for a receiving person in visual form are well known. However, such facsimile technology does not accommodate situations where the supplier of information needs instantaneous transfer of data for visual viewing by a receiver (customer) directly during the telephone conversation. There are several devices that purport to allow alternate voice and visual display data via telephone lines for special purpose applications, but none of them really provide a general, user friendly system. Lacking is a system in which an agent can intersperse visual display transmissions over the same telephone to a user or receiver between sentences in a voice conversation almost on a real time basis and within the time constraints of natural pauses in the conversation so as to not be disruptive of the conversation. The U.S. patent no. 4,656,654, issued to Neil S. Dumas, describes a more complex conferencing system in which both the agent and the receivers have personal computers and speaker phones, and either one of them can interrupt voice communication through the speaker phones to send data from one personal computer to the other. However, that system is not particularly user friendly, requiring the agent and the receiver to be computer literate enough both to go through a fairly complex set of menu selections, and the visual data transmission requires a quite significant pause or interruption in the voice conversation. The Cooper-Hart patent, U.S. 4,715,059, and Walker patent, U.S. 4,845,636, both transmit images captured by a video camera during a voice communications. The Brown patent, U.S. 4,700,378, is an example of a system in which a .user or receiver wants to access a 'data base to receive visual data displays via telephone lines and is prompted by a voice synthesizer at the database operator to press certain telephone touch tone buttons to do so. There are also several devices that can switch between modes automatically, such as: U.S. Patent No. 4,815,121, entitled COMMUNICATION APPARATUS RECOGNIZING SPEECH AND AUTOMATICALLY SWITCHING FROM DATA TO SPEECH TRANSMISSION, issued in the name of Yoshida on March 21, 1989, and assigned to Canon Kabushiki Kasisha, and U.S. Patent No. 4,908,851, entitledFACSIMILE APPARATUS OPERABLE IN FACSIMILE OR CONVERSATION MODE, issued in the name of Kotani et al., on March 13, 1990, and assigned to Sharp Kabushiki Kaisha. Yoshida solves the problem of selectively switching between the data and speech transmission by use of a voice detector. Kotani et al. automatically switches over to voice when the standard facsimile hand shake signals are not received. However, these devices are not conducive to multiple switching back and forth, concurrent with on-going voice communications, and they still can leave the less sophisticated users bewildered. Simultaneous with the upsurgance of new telephone equipment was the development and popularization of the personal computer and modems which facilitate the transmission of digital data between computers over standard telephone lines. However, modems do not, in and of themselves, solve the problem of obtaining and displaying data for the average telephone user. These modems are often associated with extensive equipment including computers and display terminals, and they still require relatively sophisticated levels of imderstanding and abilities to use them. Also, as with facsimile machines, not all modem users are in a position to have a dedicated telephone line for data only. Switching between normal voice telephone line usage and data transmission usage can be done, for example, as taught by U.S. Patent No. 4,723,268, entitled DUAL MODE PHONE LINE INTERFACE, issued in the name of Newell et al. on February 2, 1988, and assigned to International Business Machines, which includes a method of providing the required FCC billing delay for auto answer modems that can be selectively switched between human answer telephone set modes and modem modes. Modems with their ability to communicate digital data over telephone lines have opened up a whole new world of information exchange. An example of some of the possibilities were contained in U.S. Patent No. 4,387,271, entitled COMBINED TELEPHONE AND DATA-TRANSFER SYSTEM, issued to Artom, on June 7, 1983, and assigned to CSELT Centro Studi e Laboratori Telecomunicazioni S.p.A. Artom describes subscriber controlled receipt of information by a telephone receiver, a personal computer, and a television by way of a local telephone line. Artom offers some wonderful possibilities for the future of home entertainment and information systems, however such total systems can be rather costly, complex, and still require a fair amount of expertise to operate. A patent by Barsellotti incorporated a modem internal to a telephone unit for the purposes of receiving and displaying limited visual data, such as the telephone number called. This Barsellotti patent, U.S . Patent No. 4,608,686, entitled TWO WIRE VOICE AND DATA SUBSCRIBER LOOP, issued to Barsellotti, on August 26, 1986, and assigned to the Mitel Corporation, was a step in the right direction. However, once again, it requires special, complex, and expensive equipment. In a concept similar to Barsellotti, Vij et al., provided a telemarketing system in which a telemarketing switching network can distinguish between several incoming lines. With this device, as disclosed in U.S. Patent No. 4,788,682, entitled TELEPHONE SYSTEM ADAPTED TO TELEMARKETING, issued to Vij et al., on November 29, 1988, and assigned to Northern Telecom Limited, product information associated with a particular phone number can be transmitted to a telemarketing agent along with the call itself. Several other inventions have also addressed some special aspects or problems in combining voice and data transmissions. For example, U.S. Patent No. 4,827,085, entitled VOICE AND IMAGE TELECONFERENCING SYSTEM INCLUDING PAPERLESS FACSIMILE MEANS, issued to Yaniv et al. on May 2, 1989, and assigned to Ovonic Imaging Systems, Inc., describes a touch-sensitive display screen with a typical teleconferencing phone, which allows users to sketch a drawing by touching a screen and then transmit that sketch to another user with a similar device. Another patent that extended this idea of combined voice and data communications is U.S. Patent No. 4,659,876, entitled AUDIOGRAPHICS COMMUNICATION SYSTEM, issued to Sullivan et al. on April 21, 1987, and assigned to SPI Soft Pac International. This Sullivan et al. patent shows combined interactive graphics and audio communication with computer-like display screens on telephones. As with many previous devices, this Sullivan et al. invention requires rather expensive, complicated equipment to replace existing conventional voice communication telephones, and it requires two users of relatively equal and high level sophistication, both with the same equipment. Consequently, while there are many new innovations in telephone and computer equipment and technologies relating to concurrent voice and data transmission, they either require relatively sophisticated users and special, complex and expensive equipment, or they lack high quality, reliable, and nonobtrusive performance qualities necessary to make them widely acceptable and useable to a wide range of consumers. Such equipment often is designed to replace conventional voice telephone devices as opposed to merely adding to them, and those users who possess an anti-computer bias, cannot afford such high-tech equipment, or for whatever reasons are either unable or simply not interested or willing to acquire the necessary expertise or equipment, are essentially left out. As a result, there was, prior to this invention, still not any equipment available that enabled a person to receive and view visual data over the telephone line concurrent with voice conversation, hile interacting with a person who wants to transmit such visual data, and using equipment which allows the receiving party to remain almost completely passive in the visual data transmission process and in the use of the equipment. Thus, prior to this invention, there was nothing available, for example, to allow a travel agent to display a travel itinerary or a broker to display the details of a financial transaction almost instantaneously and concurrently with voice communications over the telephone lines to an average telephone user. Disclosure of Invention Accordingly, a general object of the present invention is to provide a communication system which is capable of providing a more efficient, faster, less expensive, and less error-prone exchange of information. Another object of the present invention is to provide a telephone system for both audio and visual transmission which requires less equipment and only equipment of a less complicated nature from the receiver's standpoint than heretofore available. Further, it is an object of this present invention to provide a telephone system with greatly expanded data display capabilities and possibilities, such as access to enormous databases, despite having fewer and less complicated pieces of equipment. It is yet another object of the present invention to provide a telephone system in which a receiving party can be provided with both audio and visual access to information and data bases, or merely to get visual confirmation of transactions without requiring that receiving party to be skilled in the use of computers or possess expensive and complicated equipment. A more specific object of this invention is to provide a telemarketing or other consumer access system that combines all the advantages of interacting with a live agent or service provider with a visual display of information or data useful to a caller. A further object of this invention is to provide a visual data access system for consumers that is truly "user friendly" by combining speed and accessibility of computer technology and data transmission and display with concurrent human voice interaction wherein the sender controls and operates the visual data transmission and the receiver simply views it. Still further, it is an object of the present invention to provide such a telemarketing system which can utilize and take advantage of the existing conventional telephone equipment of both the service provider and a consumer or caller- Another specific object of the present invention is to provide an' audio-visual telecommunication system which requires no new tariffs or changes to the existing public switching equipment and lines. Additional objects, advantages, and novel features of the invention shall be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by the practice of the invention. The objects and the advantages of the invention may be realized and attained by means of the instrumentalities and in combinations particularly pointed out in the appended claims. To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the system and apparatus of this invention may comprise a subscriber or receiver station in which a display terminal is added to a conventional telephone or other voice communication equipment. Such display terminal, which may be in the form of a matrix liquid crystal display (LCD), cathode ray tube (CRT), or other display technology, is capable of receiving text, graphics, and picture data. The display terminal is also essentially "dumb" to the receiver in that it is almost entirely controlled from a remote location, such as an agent position, which allows the receiver to be almost completely passive and inactive in the visual data transmission. The subscriber position may additionally include a voice/data selector, either as an integral portion of the display terminal or as a separate device. The voice/data selector is capable of selectively connecting the typical incoming telephone line to the subscriber telephone or the subscriber display terminal. The remote location agent position is similarly equipped with a telephone or other voice communication device and a display terminal, which is usually in the form of a personal computer or other data terminal. The agent display terminal may further be tied into a larger main frame computer, which the agent may utilize for storage, generation, or transmission of data. Also, the method of this invention can begin with establishment of a voice communication between subscriber and agent over the respective telephone devices. This transaction between agent and subscriber can be accomplished using existing, standard telephone lines. At a desired time during the course of the conversation, the agent can interrupt the telephone conversation momentarily and transmit display data to the subscriber display terminal, also over existing, standard telephone lines. It is preferred that this display data be encoded in some standard digital code, such as any of the large number of graphics and text protocols, or any software compatible code such as ASCII. This transmission of display data requires no effort or input from the subscriber beyond mere possession of the display terminal. Following the transmission of display data, the voice communication linkage may be automatically re-established, while the displayed data is retained. The display data may be in the form of existing pre-established patterns such as ' advertising, trademarks, option menus, price lists, news, or announcements. However, this display data may also be dynamically constructed by the agent during the telephone conversation. Such dynamic display data might include, for example, a travel itinerary, individualized grocery order lists with associated grocery item prices, purchase options, business or financial data, visual confirmation of verbal transactions or orders, or even medical information. During the typical voice communication, the voice/data selector may be defaulted to the telephone. However, the voice/data selector constantly monitors the incoming signal on the telephone line. When a particular tone sequence or other signal is detected indicating the beginning of a transmission of display data, the voice/data selector can automatically switch the incoming data stream to the display terminal. Following the transmission of display data the voice/data selector can automatically switch back to the telephone for continued voice communication. In the preferred embodiment, the agent is human, creating a friendly, personal interface between the subscriber and the database of information sought. However, the agent may also be a computer in which the transaction between agent and subscriber is provided according to a preestablished program or which is conducted through subscriber selection of menu options displayed on the subscriber display terminal, from the computer. In the latter case, the subscriber may enter his or her selection by means of pressing the appropriate keys on a touch tone phone, for example. Brief Description of the Drawings The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate preferred embodiments of the present invention, and together with the description, serve to explain the principles of the invention. In the drawings: Figure 1 is a representation of the first preferred embodiment of the telephone display system of the present invention showing both the subscriber position and agent position; Figure 2 is a schematic representation of the subscriber position display terminal; Figure 3 is a representation of the agent position arrangement of an alternative embodiment of the present invention; Figure 4 is a schematic representation of the display interface; Figure 5 is another representation of the agent position arrangement according to another alternative embodiment of the present invention; Figure 6 is still another representation of die agent position arrangement according to still another alternative embodiment of the present invention; Figure 7 is yet another representation of the agent position arrangement according to yet another alternative embodiment of the present invention; Figure 8 is another representation of the subscriber position according to another alternative embodiment of the present invention; Figure 9 is still another representation of the subscriber position according to still another embodiment of the present invention; Figure 10 is yet another representation of the subscriber position according to yet another alternative embodiment of the present invention; Figure 11 is a block diagram of the protocol layers of the telecommunications system of this invention; Figure 12 is a simplified schematic of the principal components and functions of the user's terminal; Figure 13 is a simplified schematic of the principal components of the agent's terminal; Figure 14 is a block diagram of the high speed transmitter functions of the modem IC; Figure 15 is a block diagram of the low speed transmitter functions of the modem IC; Figure 16 block diagram of the dual tone transmitter functions of the modem IC; Figure 17 is a block diagram of the low speed receiver function of the modem IC; Figure 18 is a block diagram of the high speed receiver function of the modem IC; Figure 19 is a flow chart of the link establishment procedure at the terminal that initiates a data transfer; Figure 20 is a flow diagram of the link establishment procedure at the terminal that responds to the link establishment initiated in Figure 19; Figure 21 is a flow diagram of the link turn around procedure for the terminal was just previously receiving data; Figure 22 is a flow diagram of the link turn around procedure for the terminal that was just previously sending data; Figure 23 is a flow diagram of the retry procedure for link establishment; Figure 24 is a flow diagram of the link tear down control; Figure 25 is a block diagram of the display reformatting feature of this invention; Figure 26 is a schematic representation of the text change reformatting function for producing a reformatted target screen display of data from a source screen display according to this invention; Figure 27 is a schematic representation of the block move function of the reformatting application of this invention; and Figure 28 is a schematic representation of the add text function of the reformatting application of this invention. Best Mode for Carrying Out the Invention The telecommunication display system 8 of the present invention, as shown ' in Figure 1, enhances traditional telephone voice communication with a user's or subscriber's display terminal 14 positioned at a subscriber or receiver location 10, which display terminal 14 is capable of receiving text, graphics, pictures, and omer visual information during the course of voice communications . One application of the present invention is to the telemarketing or telephone sales industry, and it is this application which is depicted in Figure 1 with telemarketing center 60. The use of this telemarketing application in this specification is for the purpose of facilitating the description of the principles and components of this invention and is not for the purpose of limitation, since other applications are possible, as will be discussed below. A typical telemarketing center 60 might have one or more telemarketing agent positions, depicted generally in Figure 1 as agent positions 61 and 65. Because of these multiple agent positions 61, 65, telemarketing center 60 may also contain telephone switching system 70 in the form of a PBX, central office switch, or other network switch. When a telephone call from a remote location, such as a subscriber position 10, is received by center 60, switching system 70 directs the call to one of the agent positions, such as, for example position 61. Such a telephone call may typically be predominated by voice communication using plain old telephones 12 and 62, respectively. However, at desired times during the conversation, a telemarketing agent (not shown) at position 61 can momentarily interrupt the telephone conversation and transmit data or messages over standard telephone trunk 54 and line 52 to a display terminal 14 at the subscriber's location 10 for viewing by the subscriber (not shown) and possible discussion. The standard telephone trunk 54 line 52, along with the public telephone system 50 and standard telephones 12 and 62, are typical of the standard, state of the art analog telephone systems that are provided by public utility companies to businesses and homes and are commonly referred to as "plain old telephone system" or "POTS." The display operation according to this invention is self-contained and controlled totally by the telemarketing agent at position 61, requiring nothing more from the subscriber at location 10 than the possession of the display terminal 14 and passive viewing of the data displayed. Terminal 14 is fed by a standard telephone line 52, which is usually analog, from a Public Switched Telephone Network 50, in other words, a plain old telephone system or POTS, as described above. Display terminal 14 is essentially "dumb" in that it does not require active input from the subscriber or receiver, but is controlled almost entirely and remotely by the telemarketing agent at position 61. The telemarketing agent has a conventional telephone device 62, which may support analog or some other telephone protocol, as determined by switching system 70. Telephone 62 is connected by telephone line 63 to switching system 70. The agent at location 61 can have a data terminal 64, connected by data interface 82 to a host computer 80. Host computer 80 might not be necessary in some applications, if data terminal 64 is, for example, a personal computer or similar equipment. Data interface 82 can be whatever is appropriate to match existing protocol between host computer 80 and data terminal 64, such as, for example RS-232 or 3270 protocol. Also associated with agent position 61 , as shown in Figure 1 , but not necessarily in proximity of telephone 62 or data terminal 64, is a modem 72, which is connected between host computer 80 and the switching system 70 by data interface 84 and telephone line 74. In this embodiment, the host computer 80 has stored therein one or more data bases or other data, some of which the subscriber or receiver might wish to see. Such display data is down loaded to the subscriber from the host computer 80 along a different line, i.e. line 74, to switching system 70, and then to the telephone trunk 54 upon which voice communication travels. However, the agent at position 61 still controls the transmission of this display data from position 61, primarily by appropriate input to data terminal 64. Similar to agent position 61, agent position 65 can include a conventional telephone device 66, which also may be analog or other protocol, a data terminal or personal computer 68, and a modem 76. As indicated above, there might, and will typically, be several other telemarketing agent positions in addition to positions 61 and 65, using the same host computer 80 and switching system 70. However, such other agent positions need not be shown for the purpose of describing this invention and, for simplicity, are not shown. In operation, a telecommunication linkage is established and conducted primarily by a voice connection between subscriber telephone 12 and telemarketing agent telephone 62 in a conventional manner, such as by either the subscriber or the agent dialing the other's telephone number. For example, this communication can be initiated by the subscriber (not shown) at location 10 making a call to the telemarketing center 60. This call is routed at the subscriber's position 10 from telephone 12 along telephone line 22 through display 14 and then out along telephone line 52 to the public telephone switching network 50. More information concerning the workings of display 14 and the internal pathway for this calling signal will be described below. This call is then routed by the Public Switched Telephone Network 50 to the telemarketing center 60 in a conventional manner, where it is received at switching system 70. Switching system 70 may be any common system available on the market, such as those currently available from AT&T ™ , Northern Telecom ™ , or Rockwell ™ . Software internal to switching system 70 locates and directs the call to a free agent, such as, for example, agent position 61. As soon as this incoming call is received at switching system 70, a three-way conference call arrangement is established between: (1) the incoming call from subscriber at location 10 along line 52, network 50, and trunk 54; (2) agent telephone 62 along line 63; and (3) associated modem 72 along line 74. The three-way conference call arrangement ensures there will be sufficient connections available within switching system 70 when the agent desires to transmit display data. The assurance of available connections provided by this three-way conference is especially important for large telemarketing centers containing numerous agents at numerous agent positions. During the course of the voice communication, the telemarketing agent at agent position 61 can be formulating or deciding on the display to eventually be transmitted to subscriber location 10, with or without verbal input, requests, or suggestions by the subscriber. Such display data may already exist in whole or in part, or in random order in the data terminal or personal computer 64 or host computer 80. Alternatively, all or parts of these displays may be generated dynamically from data bases or may be entered directly from the keyboard, floppy disk 67 (shown on personal computer 64 in Figure 1), hard disk, or other input means at data terminal or personal computer 64. At an appropriate time during the telemarketing communication, the agent at location 60 can activate a data transmission command from data terminal 64, which is detected by host computer 80. Computer 80 in turn notifies software internal to switching system 70, via control line 78, to send out an appropriate signal along trunk 54, through Public Switching Network 50, and along telephone line 52, eventually arriving at a signal-activated display terminal 14 at the subscriber location 10. This appropriate signal causes display 14 to switch from a voice commumcation linkage with telephone 12 to a data commumcation linkage with display screen 20, as will be explained more fully below. Once the voice commumcation linkage has been temporally suspended and the data communication linkage has been fully established from data terminal 64 through host computer 80 to subscriber display 14, the transmission of the display data is initiated. Host computer 80 then sends out the digital encoding of the desired display by way of line 84 to modem 72. Modem 72 may be a standard or special modem that is capable of modulation and demodulation of binary digital information into audio tone signals suitable for transmission over standard analog telephone lines. This modulated digital signal is transmitted to switching system 70 by line 74, where it is sent out to display terminal 14 immediately following the appropriate display activating signal sequence. The remainder of this data transmission connection is through trunk 54, public telephone switching network 50, and telephone line 52 to display terminal 14. This display data transmission may be accomplished in standard ASCII code, especially if it . only comprises written material, to keep data transmission time to a minimum, as opposed to the pixel-by-pixel transmission that is common with facsimile devices, video cameras, and other display data. This ASCII code is mentioned for the sake of example and not for limitation as the display transmission may be in any other standard digital software code or protocol as well. A typical display transmission will take in the range of about eight seconds when transmitted at a baud rate of 2400 bits per second, as will be discussed more fully below. Following transmission of the display data, the voice communication is immediately re¬ established automatically between telephones 12 and 62. Display of data on screen 20 is retained by display terminal 14 in a fixed manner, even after re-establishment of voice communication, thereby facilitating verbal discussion of the data, as well as allowing the subscriber or receiver of the data sufficient time to assimilate and study it to his or her satisfaction. The apparatus and process for automatic re-establishment of voice commumcation according to this invention will be described in greater detail below. As an example, if the telemarketing agent is an airline ticket sales person or travel agent, he or she can put together a proposed travel itinerary during the course of, and in response to, the voice communication portion of the telecommunication transaction. Such travel itinerary may be generated, for example, utilizing information contained locally at data terminal 64 itself, or it may be created from information contained in a larger data base within host computer 80, with active inputs and data selections by the agent on the keyboard or oώer input device of the data terminal 64, but without requiring any active computer inputs or interfacing by the subscriber. Then at the appropriate time, when the travel agent wants to show the subscriber (traveler/ticket purchaser) this purposed travel itinerary, he or she can input an appropriate code or signal to data terminal 64 and thereby initiate transmission of the itinerary data for viewing on the subscriber terminal 14. Additional examples of the types of data that may be displayed during a telemarketing communication include description of goods or services and their prices for comparison purposes or visual confirmation of an order. As an alternative, the agent switching system 70 can even be set up to transmit a display upon initial receipt of a call, while the call is being queued for a free agent or while the subscriber is on hold awaiting a free agent. Examples of such initial displays may be the telemarketing center's logo or trademark, or other displays such as a recipe of the week for phone orders placed to grocery stores. Terminal 14 should be fitted with a minimum of user controls, which in this case may be an on/off switch 24, a screen scroll button 16, a screen clear button 18, and picture controls 15. Picture controls 15 may include a contrast control and, in the case of a CRT screen, a brightness control. The other control 19 is optional print button, and will be discussed below. In keeping with the principles of this invention, which teach an essentially "dumb" or passive terminal, terminal 14 contains no keyboard, hard disk, floppy disk, or other means of data entry locally at subscriber location 10, although it could also be equipped with those kinds of active input, data processing, and data storage devices, if desired. Display terminal 14 contains internally a -voice/data selector 25, as shown in Figure 2. Voice/data selector 25 establishes a three-way communication linkage at junction or node 29 between incoming line 52, telephone line 22 attached to telephone 12, and data line 38. Data line 38 is further fed through modem 26 and data line 32 to microprocessor 30. This three-way linkage is similar to the three-way conference call linkage established at the agent switching system 70. Voice/data selector 25 includes a switch 33, which is set to a normally closed position, as shown in Figure 2, to allow voice communication, whereby the incoming line 52 is connected to telephone position 12 (Figure 1) by way of line 22. A line monitor 28 scans the incoming signals on line 52. When the monitor 28 detects the particular signaling sequence indicating the beginning of a data transmission, as was discussed above, it alerts microprocessor 30 in such a manner that microprocessor 30 in turn actuates switch 33 via path 44 to the open position, thereby momentarily disconnecting voice commumcation from or to subscriber telephone set 12 (Figure 1). Microprocessor 30 also activates modem 26 or causes it to go offhook via control line 42, as well as alters display screen 20 via control path 46 to the reception of display data via line 32. This activation establishes a data commumcation linkage such that modulated digital data enters along incoming line 52 and is transmitted by line 38 to newly activated modem 26 for demodulation. The digital data is then transferred from modem 26 via line 32 and through micro-processor 30 to display screen 20 where it is displayed. Microprocessor 30 and/or modem 26 handles all the necessary electronic handshaking and protocol typical of data transmissions. On subsequent transmissions of displays during the course of a single voice communication event, less handshaking or possibly even no handshaking may be required. Microprocessor 30 may include a peripheral interface 31, which interfaces with most of the remaining components of display terminal 14, and a microcontroller 35, which acts as the central processing unit of display terminal 14. Microprocessor 30 may additionally include permanent memory storage capability ROM 39, which may contain operating instructions or even fixed displays internal to terminal 14. Additionally, temporary memory storage capability RAM 37 may be included in the general block microprocessor 30. As described briefly above, actuation of switch 33 to its alternate state 33' also disconnects the telephone receiver 12 from the incoming line 52 during transmission of digital data. When this momentary disconnect occurs, telephone line 22 is alternately connected to tone source 36 during data transmission. Tone source 36, which is in an always on, ready state, as will be further described below, generates a pleasing tone that is heard over the telephone device 12 in place of the incoming modulated digital data. The pleasing tone of tone source 36 informs the subscriber or receiver on telephone 12 that he or she has not been totally disconnected from the agent position 61.' A simulated voice message could also be used in place of, or in addition to, tone source 36 to inform the subscriber what is happening, and requesting that he or she stay on the line until the data transmission is complete. A default written message to the same effect could also be displayed on the screen momentarily while the data transmission is occurring. Such a default message may be stored internal to display terminal 14 itself, in either RAM 37 or ROM 39, and actively delivered to display screen 20 along data path 48 by microprocessor 35. The end of a data string, therefore, the end of a data transmission, is detected by modem 26 or microprocessor 30. The end of a data transmission may be identified by microprocessor 30 by an end of file (EOF) marker or by modem 26 due to the end of the signal carrier. Once the end of data is detected, microprocessor 30 then generates a signal to re-activate switch 33 to its normally closed mode to re-establish the voice communication linkage to telephone set 12 while disconnecting die tone generator 36. Modem 26 then shuts down or goes onhook after the appropriate delay, thereby disconnecting the data communication linkage to display screen 20. As already mentioned, display terminal 14 may be provided with the memory and software capabilities, such as RAM 37 or ROM 39, for storing several screens of display data. Variable memory space, such as provided by RAM 37, could be used to dynamically store several display screens, either during the course of a single telephone conversation or for later reference after the completion of a given telephone conversation. In the case of fixed special message display screens, which for example may read "Please Stand By For Receipt of Display Information," the display information is stored in permanent memory, ROM 39. Such additional stored screens could then be transmitted back and forth between display screen 20 and microprocessor 30 by data path 48. In the absence of power, such as during a black-out, switch 33 remains in its normally closed position allowing telephone device 12 to operate in normal voice transmission mode despite the inhibited display functions. Similarly, if power is lost during a data transmission, switch 33 returns to its normally closed position to allow continued normal operation of telephone 12. An alternative embodiment of agent center 110 is shown in Figure 3. Only one agent position 61 is shown in center 110 for simplicity. However, this embodiment is equally adaptable to multiple agent positions. Center 110 contains the same agent switching system 70 and host computer 80 as the previous center 60. Similarly, agent position 61 also contains the same data terminal 64, connected to host computer 80 by data interface 82, and the same conventional telephone 62. The preferred feature of agent center 110 is a display interface 100. The three-way conference call connection among the switching system 70, the telephone 62, and the data terminal 64 is set up in display interface 100 instead of in switching system 70. Therefore, only one telephone line 90 need be directed to each agent position from switching system 70. This arrangement 'allows easy installation of the telecommunication display system of this invention without modification of existing switching equipment 70 and software. This three-way connection is between incoming line 90, telephone line 92 also connected to telephone 62, and data interface 94 connected to data terminal 64, and it occurs at node 129, as seen in Figure 4. Display interface 100, shown in Figure 4, is very similar to the organization and structure of display terminal 14, except that it has a port 121 instead of a display screen 20. Port 121 may be an RS-232 serial port or other appropriate control interface. Display interface 100 does have a microprocessor 130, an internal modulator/demodulator or modem 126, tone or signal generator 136, and a line monitor 128. Line monitor 128 may be a standard touch tone receiver chip such as, for example, a Teltone" M-957-01, if the intended data transmission identification signal is a touch tone signal. Line Monitor 128 allows display interface 100 to function as in a similar fashion to line monitor 28 in voice/data selector 25 by alerting microprocessor 130 in the event of the possible reception of display data from a peer with a similar capability of transmitting display data. Microprocessor 130 may contain a peripheral interface 131 and microcontroller 135, and it can also contain temporary memory storage space in RAM 137 and permanent memory storage space in ROM 139, in the same fashion as those discussed above with reference to microprocessor 30. In this way, display interface 100 allows operation both for an agent and a subscriber equipped with a personal computer, such as terminal 64 in peer communication. Display interface 100 may even be in the form of a card installed internal to personal computer 64, in which case telephone lines 90 and 92 would be reconnected directly by jacks (not shown) to the back of personal computer 64. In operation of the equipment at the agent center or position 110, when an agent at location 61 desires to transmit some graphics or other display data, he or she enters the appropriate command on the data terminal 64. Data terminal 64 in turn notifies microprocessor 130 in display interface 100 via interface 94, port 121, and control line 148 to begin to set up a data transmission. Microprocessor 130 activates modem 126 by taking it offhook via line 142, and flips switch 133 by way of line 144 to its alternate position 133'. A standard digital sequence indicating the beginning of a data transmission may be generated by internal modem 126. However, if for security reasons it becomes necessary to have a specialized digital sequence or inband signal, such a special sequence or signal can be generated by modem 126 or other circuity within display interface 100. Such a signaling sequence would inhibit unauthorized access to a subscriber position display terminal 14. As before, no changes would be required to the serving switch 70 or to the public telephone switching network 50 with such a signal. Once the initial data alerting string actuates modem 126, the digital data can be down loaded from the data terminal or personal computer 64 through port 121 and data 132 to internal modem 126 for modulation. Once modulated, this display data can be sent down line 138 and out line 90 to the subscriber location 10, where it is received, processed, and displayed as described above. Actuating switch 133 to its alternate position 133' breaks the voice communication linkage between telephone lines 90 and 92 temporarily by connecting telephone 62 to tone generator 136 by way of line 92. This configuration prevents the transmission of the digital data from being heard on telephone receiver 62. Signal generator 136 can send out a pleasing tone or other audible message indicating data transmission is under way. After the transmission of digital data, personal computer 64 sends an end of data transmission signal by way of interface 94 through port 121 and control path 148 to microprocessor 130. Microprocessor 130 then re-activates switch 133 to re-establish the voice communication connection between lines 90 and 92. A message is also sent from microprocessor 130 by way of path 146 through port 121 and interface 94 informing data terminal or personal computer 64 of the completed transmission. Subsequent to data transmission, modem 126 goes onhook after an appropriate delay, which for the sake of example and not intended as a limitation, could be one second. As with the previous subscriber position modem 26, modem 126 at the agent's end can be any standard off die shelf modem or comparable device. For die sake of illustration and not intended as a limitation, modem 126 may be, for example, any stock 2400 Baud Hayes ™ modem. As described above, modem 126 can be set to go onhook after an appropriate delay of one second. This onhook delay time can usually be adjusted with typical off the shelf modems, such mat this feature is disabled and d e modem never goes onhook, or up to about 25 seconds. As described above, a one second delay seems appropriate with the present invention. One second is long enough to ensure me end of data, while not creating an unnecessarily long delay. Display interface 100, similar to display terminal 14, also allows die maintenance of voice communication if power is lost by switch 133 remaining in the normal closed position between telephone lines 92 and 90. This operation occurs in a similar fashion to the procedure described above witii reference to terminal 14. Another alternative embodiment agent center 120, which can also include one or more agent positions 61, is shown in Figure 5. Center 120, with its represented agent position 61, can be substantially die same as center 110 of Figure 3, except mat port 121 is connected directly to host computer 80 by interface 124 rattier than to personal computer 64. As before the displays to be transmitted may either be called up from existing and stored displays or generated dynamically via data terminal 64. In either case, in this embodiment 120, the display is sent directly from or routed dirough host computer 80. In a further alternative embodiment 130, one or more telemarketing agents can be replaced by a recorded voice information system 140, as shown in Figure 6. Voice information system 140 may be an audiotex system, such as, for example, Conversant ™ manufactured by AT&T" . Further, voice information system 140 may be a voice mail service, such as one of the several model available from Octel" . Recorded voice system 140 may further be an integral part of die switching system 70, or it can be external to switching system 70, such as the system 140 shown in Figure 6- Recorded voice system 140 may also be connected to host computer 80 (not shown in Figure 6). Embodiment 130 uses the same display interface 100 as described in die previous embodiments with telephone line 152 connected to recorded voice system 140. In embodiment 130 data transmission path 154 connects a display generator 156 to port 121 of display interface 100. Display generator 156 may be a separate processing system or combined widi system 140. Display generator 156 is in communication with audiotex/recorded voice system 140 by linkage 158. During operation of embodiment 130, the primary mode will again be voice communication. Typically, a subscriber or user will call into the audiotex or voice mail system 140, thereby establishing this voice communication. Once established, voice system 140 initiates preprogrammed messages, or audio instructions, which may be in the form of a menu of options, such as, for example "press one to listen to your messages, press two to record a new greeting, etc." At me appropriate point, the voice information system 140 will notify the display generator 156 to begin the conversion to data communication, as described above. A standard voice mail service 140 can record voice mail messages. These recorded voice mail messages may additionally be displayed by phone or extension number, date, and time called on d e display terminal 14. When the subscriber dials into service 140 to retrieve his or her messages, voice mail service 140 may transmit a display listing the message. The subscriber can tiien select in a menu access fashion those voice mail messages he or she wishes to hear and in which order he or she wishes to listen to mem. Accordingly, random access could be afforded to a voice mail system instead of the traditional, painstaking, serial access method. Several such audiotex or voice mail systems 140 may be connected dirough a common gateway 160, as shown in Figure 7. Such gateways are common in die industry. A caller, possibly with a display calls into gateway 160 via trunks 54. Based upon number dialed or od er selection criteria such as a caller inputted digits, gateway 160 then directs d e call to any one of several systems 140. Gateway 160 could generate its own displays or displays in association with systems 140 by use of an internal display generator 162. This allows both oral communication wim a caller via systems 140 as well as transmission of display data via display generator 162, without requiring systems 140 to have their own display generator associated with them. Referring again to Figure 1, display screen 20 portion of display terminal 14, as shown and described above, is a flat screen, liquid crystal display (LCD). However, display terminal could also be a LCD or an electro-chromic, eletroluminescent, plasma discharge, or vacuum fluorescent display, as well as a more conventional cadiode ray tube (CRT) or any other visual display device, including a portable pocket-sized screen, as would be obvious to persons skilled in mis art after becoming familiar with the functions and components of mis invention. Now referring back to Figure 2 to offer a few more details, die nature of line monitor 28 may vary depending upon die nature of die signaling sequence used to indicate die beginning of data transmission. Such a signaling sequence may be DTMF or MF tones. If d e signaling sequence is a DTMF signal, as might be sent by a DTMF sender chip, which may be internal to modem 126 (Figure 4), then line monitor 28 could be a DTMF receiver chip, which for the sake of example and not for limitation could be a Teltone" M-957-01. Also for the sake of example and not intended as a limitation, micropressor 30, including peripheral interface 31 and microcontroller 35, may be any one of several micropressor integrated chips such as an Intel ™ 8051 microprocessor. Further, the RAM 37 may be any standard integrated chip, but again for the sake of example, may be comprised of multiple Harris ™ 65162 chips, which are 2000 X 8 bit static RAM chips. The display terminal 14 features of the present invention may be further augmented by the addition of a printer (not shown), which could generate hard copies of the displays received by terminal 14. The printer could be queued by any optional print screen button 19, as shown in Figure 1. The printer could be any standard computer printer such as an EPSON" LQ-1000. More elaborate printers such as the Apple Laser Writer Plus" or the Hewlett Packard Laser Jet Series HI" would be equally applicable, however, diey may have more capabilities than would be required with the present invention. A screen 20 with 80 columns by 25 rows should be enough to display a complete travel itinerary or a complete audiotex menu. At 2400 baud, a complete display of 2000 characters or about 300 words, can be transmitted in approximately eight seconds, which compares to only about 10-20 words, spoken intelligibly, in die same time interval. The on/off switch 24 on display terminal 14 need only be activated once upon initial set-up and installation of display terminal 14. Terminal 14 may remain in a constant on, ready posture from that point on. This constant on, always ready posture includes power being constandy supplied to tone generator 36 and microprocessor 30, as well as die other components of display terminal 14, with reference to Figure 2, such that they are in an always on and ready state. Accordingly, on/off switch 24 need not be in a predominate position, such as the front or side as depicted in Figure 1. Ra ier on/off switch 24 may be located in the back, behind a panel, or in some odier concealed place. Display terminal 14 can retain a given display on screen 20 after voice communication is re- established during a given telecommunication event, and it can also retain the display after die termination of such event when botii parties have disconnected. A given display may merefore be retained and displayed indefinitely, until clear button 18 is pressed or anotiαer display is received. Accordingly, the display terminal 14 may also serve as a visual answering machine or notification device. For example, terminal 14 can be set-up to act as a visual answering machine or in d e alternative, terminal 14 may act as a notification device independent of a traditional telephone device 12, as seen in embodiment 170 in Figure 8. Then when a call is received, terminal 14 will answer die call under appropriate conditions, eittier answering machine mode in embodiment 10 from Figure 1, or as a notification device in embodiment 170 from Figure 8, and is ready to display a given transmitted display. Such display would flien be retained until die subscriber arrives back at location 10 for viewing. If e display terminal 14 has provisions for storing multiple screens of information, such as RAM 37 as described above, it can answer and record multiple screens of information for later viewing. Additionally, a typical voice recording answering machine 112, found in embodiment 180 and shown in Figure 9, can also be connected to telephone line 22. Answering machine 112 may be either internal or external to telephone device 12. In this embodiment 180, answering machine 112 could be set to auto-answer for the purpose of recording messages or screening calls as is well known in the industry. Upon receipt of a call, the three-way communication linkage could be established at node 29 in display terminal 14 (Figure 2). If the caller desires to leave a voice message, switch 33 could remain in die normally closed position connecting incoming line 52 to answering machine 12 via telephone line 22, and a voice message could be left on the voice answering machine. However, if me caller wished to leave a display message in addition to, or instead of, a voice message, the appropriate signaling sequence could be transmitted down line 52. This signaling would still be detected by line monitor 28, as described above, activating microprocessor 30 and altering display screen 20 for the reception of the given display. During me transmission of die display, a pleasing tone generated by tone source 36 would be left as a message on answering machine 112. As described above, die caller can be re-connected to answering machine 112 following transmission of display data. It is also possible for a telephone device and a display screen, such as the above-described telephone 12 and display terminal 14, to be combined into a single unit 182, as shown in Figure 10. The structure and operation of such a single unit 180, with its display screen 190, handset 182, and digital or analog dialing mechanism 184 is similar to that described above with reference to separate devices 12 and 14. A single unit device 180 may be in die form of a private phone for personal or business use or in the form of a public telephone such as a courtesy or pay phone in hotel lobbies, airports, or restaurants for example. Such a public display phone 180 could be used by travelers to make airline reservations widi a visual confirmation, by business people to exchange financial information, or by the general public to access the above-described audiotex or voice services 140, (shown in Figures 6 and 7). Examples of consumer to business applications in addition to those given above include banking transactions, emergency hodine services, and entertainment. Examples of business to business applications include employee informational services, ordering of parts, daily news letters, and general information dissemination from headquarters to branch offices. Additionally, for business applications die above-described subscriber/agent relationship, could be replaced by an employee/employer relationship where each employee could play die role of agent in a peer-to-peer arrangement. A few possible examples of uses for specialized audiences include university course registration, hotel billing, notification services, and medical emergencies. Consequently, the applications for this invention are not limited to commercial telemarketing operations, but can be any situation where an active holder or creator of data or information needs to transmit the data for visual display to a passive viewer or receiver over the same telephone line on which they are having bidirectional verbal communications. The present invention can further serve as a service for the hearing impaired or any user who must operate in a noisy environment. Ald ough the present invention cannot directly access CompuServe" and odier videotex services or such public access databases, such as Prodigy", Lexis ™ , and Dialog ™ , it can access a knowledgeable agent as described above who may have direct access to such services. Such public consumer databases require special equipment, knowledge, and frequently special training, which inhibits such use by persons who are not inclined to encounter those public consumer databases on those terms. The present invention may allow a consumer or subscriber access to diese or similar databases with the benefit of a knowledgeable, helpful human agent at a telemarketing or other remote location to perform the complex user steps for the consumer to access such data. Additional features are possible if the telephone switching system 70 can identify whether or not a caller is set up widi a display terminal 14. Upon receipt of an incoming call, switching system 70 could respond widi a pre-recorded greeting, followed by a prompt to me caller, such as, for example "press one if you have a display terminal." Such a determination of whether a caller has a display terminal 14 by switching system 70 may also be accomplished by way of an automatic query of line being transmitted. In which case, if die caller had a display terminal 14, microprocessor could receive and recognize the automatic query and respond widi an appropriate signal indicating the presence of a display terminal 14. All of which could be accomplished wi out any effort or input on die part of the caller. If the subscriber can receive displays, die above described diree-way conference calling arrangement can be established and an initial display, including a trademark, advertising, or other useful information can be sent, while the call is queued to an agent station 61. Further, die agent at position 61 can be informed, possibly by an appropriate message from switching system 70 or from host computer 80 for display on terminal 64, as to whether or not a caller has a display terminal 14, such as subscriber location 10. The party identification features could also be accomplished if some of me various above described elements support ISDN. The current public telephone network is analog. ISDN, which stands for "integrated services digital network", if adopted would establish a new digital network. ISDN, as currendy proposed, would include two carrier bands or channels and one channel for signaling information or data, referred to as 2B + D. It is this D or data channel which carries signaling information, addressing, part identification, and odier hand shaking or functional protocols which could be used as a substitute for the above determination of whe ier a caller has a display terminal 14. Thus, if trunk 54 supports ISDN, it would be possible for a switching system 70 to establish whether or not a particular user or subscriber has a display terminal 14, wimout requiring the above described verbal or keyed touch tone sequence such as, "Press one if you have a display terminal." Further, if die trunk 54, die public switching network 50, and die subscriber's telephone line 52, all support ISDN, then die data communication link can be established on a separate channel, and d e voice communication link need not be interrupted during display transmission. It should be understood diat me present invention neither requires nor depends on die adoption of ISDN. One of die many advantages of die present invention, as described above, is its efficient operation with the existing analog public telephone network, even though die present invention, as well as the entire telephone system and its peripherals, might be enhanced by ISDN. The features of die present invention may additionally be enhanced by a personal computer at or near subscriber location 10. The subscriber could dien exercise some control over display terminal 14 himself or herself. He or she could send display data to otiier subscribers. This arrangement would allow die possibility of peer to peer transmission, or employee to employer as described above, although it departs somewhat from die passive terminal for unsophisticated users, which is an advantage of die first preferred embodiment described above. As discussed above, one of die principal objects of this invention is die ability to transmit data for visual display accurately, but also widi minimal interruption of die voice communications. At die same time, another principal object of this invention is to allow one party or agent to initiate and control transmission of die visual display data to a passive receiver or subscriber. The receiver or subscriber needs virtually no computer training at all, other tiian to turn on the power for the display terminal 14 and possibly to use a button or knob 16 to scroll the display. Perhaps also nearly as important, the agent also needs very little computer literacy and a minimum of training to operate the system 100 from the agent's position 60. A principal feature of this invention is die protocol that meets those objectives. The protocol according to this invention is layered, as illustrated in Figure 11, including a physical layer 202, data link layer 204, and application layer 206 at the subscriber terminal 14 and similarly described physical layer 212, data link layer 214, and application layer 216 at the agent terminal 100. The physical layers 202 and 212 of d e respective terminals 14 and 100 include the computer and switching hardware that convert digital control and data information into connections and analyze signals that are required to interface with, and to transport information across die telephone network 50, as will be described in more detail below. Therefore, the physical layer 202 at the subscriber terminal 14 and the physical layer 212 at the agent terminal 100 are connected by telephone lines 52 and 74, or by suitable wireless substitutes, to each ouier through die telephone network 50, as described above. This physical connection 202 can include well-known data access arrangement (DAA) and signal conditioning circuits (not shown in Figure 11). It also includes directional coupler, high pass filter (HPF), and limiter, which will be described in more detail below. A special purpose modem integrated circuit (modem IC), such as a R96DFX MONOFAX (trademark) manufactured by Rockwell International Corporation, is included and used in the physical layer 202 for modulation, demodulation, tone generation, and tone detection, but part of it is also used in die data link layer 204 to provide HDLC (High Level Data Link Control) processing. Switching arrangements in the physical layer 202 allow a microcontroller (not shown in Figure 11) to configure die circuit into either die voice mode for normal voice communication or the data mode for reception of data for visual display, as will be described in more detail below. The data link layer 204 and application layer 206 of die subscriber terminal 14 may be perceived for purposes of tiiis description as being in direct communication widi their respective peer data link layer 214 and application layer 216 of agent terminal 100, as indicated by phantom line arrows 208 and 209, but uiey actually communicate dirough the adjacent lower layers * and dirough the telephone network 50. The data link layers 204 and 206 according to diis invention comprises essentially a modified HDLC (High-level Data Link Control) protocol that provides pocketing for outgoing data, error detection using CRC and error correction for retransmission for ensuring accuracy of die data transmission, control of line turnaround for reception and transmission of signals, and reassembly of incoming pockets into application level messages. The data link layers 204, 214 implement implicit link establishments at die physical layers 202 and 212, implements selection of data transmission speed according to certain criteria to optimize overall transmission time, and other functions as will be described below. The application layers 206 and 216 provide die sources for the data to be transmitted and the destination for data received by die lower layers. The mediod of formatting messages from the application layer is provided according to tiiis invention to allow the data link layers 204, 214 to determine when application responses, thus link turnaround, are required. Those data compression functions are also considered part of the application layer 206, and partial screen updating is implemented in die application layer. Finally, the link tear down control according to this invention is implemented in die application layers 206, 216, including deciding whedier no response, one response, or open-ended interchanges are allowed following die current application transmission before die data link is torn down. The term "response" as used here means a response from the peer application layer, 206 or 216, not die normal acknowledgements mat die data layers 204 and 214 exchange to insure data integrity. Referring now to Figure 12, die physical level 202 of the subscriber terminal 14, includes a telephone line 52 from the telephone network 50, which telephone line 52 is connected to a first relay switch 220. This first relay switch 220 is for connecting and disconnecting the subscriber telephone 12 and die modem IC 222 to and from the telephone line 52 in response to control signals from me microprocessor or microcontroller 230. The microcontroller 230 preferably comprises a microprocessor integrated circuit and associated memory and peripheral circuitry. For example, it can be a 80C32 device manufactured by Intel Corporation of 3065 Bowers Ave., Santa Clara, California 95051. When die relay switch 220 is switched to its alternate broken-line position, signals are rerouted via connection 258 and summing device 260 to the RXIN contact of the modem IC 222. The subscriber's telephone 12 is also connected by line 22, a second relay switch 222, internal connection 224, directional coupler 226, and internal connection 228 to die first relay switch 220. The second relay switch 222 also operates in response to a control signal from the microcontroller 230 to alternately connect and disconnect die telephone network 50 via directional coupler 226 and connection 228 and to connect and disconnect die tone generator/local power source 232 to and from die subscriber's telephone 12. A tiiird relay switch 234 is provided to connect and disconnect a ring detector 236 and die microcontroller 230 from me internal telephone connections 224, 228 and directional coupler 226. The system is normally defaulted to die voice mode, where all die relay switches 220, 222, and 234 are in die solid-line positions shown in Figure 12 and as described above. Therefore, when die subscriber wants to call out, he or she can do so in a normal or conventional manner by dialing the desired number and ringing out. The directional coupler 226 is fixed such tiiat signals are transmitted bidirectionally between its contacts A and B, tiius between die subscriber's telephone 12 and an outside telephone (not shown, in Figure 12, but possibly including me agent's telephone 62 in Figure 1). On the otiier hand, die directional coupler 226 allows only incoming signals on contact A to be transmitted to contact C, where die ring detector 236, microcontroller 230, high pass filter (HPF), 238, limiter, 240, and detector portions of modem IC 222, are connected to die directional coupler 226. Signals from the subscriber's telephone 12 on contact B cannot reach the contact C in directional coupler 226, so mat signals from the subscriber's telephone 12 cannot reach the detectors 242, 244 in d e modem IC 222. The directionality of d e directional coupler 226 as described above is not perfect, but it greatiy enhances reliability of initial tone detection. Essentially, therefore, the agent's terminal or display interface 100 is connected by telephone line 74 to die telephone network 50, as described above and as also shown in Figure 13. The agent's telephone 62 is connected to die terminal 100 by a local telephone line 63, and it can be selectively connected and disconnected to die telephone network 50 by relay switches 320 and 322, which are controlled by signals from the microcontroller 330. It also includes high pass filter 338 and limiter 340 for noise suppression, and a special purpose modem IC 322, which can be a R96DFX MONOFAX (trademark) device manufactured by Rockwell International Corporation of 4311 Jamboree Road, Newport Beach, CA 92658. When the agent decides to send data for a visual display to die subscriber's terminal 14, he or she designates on his or her display terminal 64 (Figure 3), the visual data to be sent, which is usually derived in an application level 216 (Figure 11) from a data base in a host computer 80 (Figure 3) and initiates a send signal at die agent's display terminal 64 (Figure 3). The agent initiates die send signal to die microcontroller 330 (Figure 13) via host computer and data interface 80, usually by pushing a designated key on his or her keyboard or by clicking on a designated spot in a "Windows" application at his terminal 64, as will be described in more detail below; however, data transmission can also be initiated automatically by computer 80 or terminal 64, or by display generator 156 in embodiment 130 (Figure 6), as described above. The physical layer 212 at die agent's terminal 14 then implements an implicit link establishment between die agent's "terminal 100 and die subscriber's terminal 14 via die telephone network 50 so tiiat die visual data from * host computer 80 can be transmitted by the agents' terminal 100 and received by die subscriber's terminal 100. Please note that for the purposes of tiiis description, die words "visual data" provides a convenient term for reference to the data usually, but not necessarily, from host computer 80 or agent's terminal 64, that is stored, transmitted, and received for the purpose of displaying in a visually perceptible format, such as on the subscriber's screen or LCD display 20, although the data obviously cannot be seen in its magnetic format for storage or in its electric format for transmission. Therefore, visual data means the data tiiat is intended for visual display, as opposed to die signals or electronic transmissions for voice communications via die telephones 12 and 64. Also, the term "voice mode" refers to the configurations of the physical and data link layers of the respective terminals 14, 100 for voice communications between die agent and die subscriber, while "data mode" refers to die configurations of tiiose elements for transmission and reception of visual data. Upon receipt of die "send" signal from the agent's keyboard or terminal 64 (Figure 3), which is designated generally in Figure 13 along widi die host data interface 80, by d e microcontroller 330, die agent's data link layer 214 (Figure 11), which is implemented by die physical layer 212 (Figures 11 and 13), initiates a signal to be sent from die physical layer 212 of the agent's terminal 100 (Figures 3, 11, and 13). Therefore, die microcontroller 330 in die agent's terminal functions bom at the data link layer 214 and at d e physical layer 212 in implementing this implicit link establishment function. To implicidy establish the implicit data link, the microcontroller 330 of me agent's terminal 100 in Figure 13 outputs signals through connections 350, 352 to the relay switches 320, 322, and 334 to change from voice mode to data mode, i.e., to switch to die alternate, broken-line switch positions, diereby disconnecting die agent's telephone 62 from the telephone line 74 and telephone network 50. Simultaneously, die microcontroller 330 also outputs a signal via connection 354 to actuate die local power supply/tone generator 332, if it is not already actuated, to provide an alternate local power supply to die agent's telephone 62 and to provide a pleasing tone or simulated voice message to assure the agent tiiat his or her phone 62 has not gone dead. Next, the microcontroller 330 configures die modem controller 346 in modem IC 322 to cause die tone generators 350, 352 to generate two simultaneous tones of different frequencies on die TXOUT terminal and send them via the telephone network to die subscriber's terminal 14 (Figure 12). These two tones can be, for example, 2312.5 Hz and 2912.5 Hz for 200 milliseconds. These two tones will signal die subscriber's terminal 14 (Figures 3, 11, and 12) tiiat visual data is coming, so the subscriber's terminal 14 can reconfigure itself to the data mode and implicitiy establish the data link, as will be described in more detail below. The microcontroller 330 men reconfigures modem controller 346 in modem IC 322 to cause die data transmit device 354 to send a number of small flag signals, e.g., six flag signals, at a low rate of about 300 bits per second (bps). A standard HDLC protocol flag, which may be used in this invention, includes six bytes of data where a 01111110 byte is standard in HDLC protocol. The flags are intended for detection by the subscriber's terminal as an indicator mat transmission speed designator signals are coming next, as will be described in more detail below. Once the flags have been sent, the microcontroller 330 (Figure 13) reconfigures the modem controller 346 again to cause die one or more of die tone generators 350, 352 to generate tone signals tiiat indicate to die subscriber's terminal 14 (Figure 12) die bit rate mat is selected for d e actual visual data transmission once the link is established. For example, a single 1412.5 Hz tone generated by tone generator 352 for 60 milliseconds indicates mat the baud rate of the visual data transmission will be the low rate, e.g., about 300 bps. A single 2312.5 Hz tone generated by tone generator 350 for 60 milliseconds may indicate die bit rate will be a medium rate, e.g., about 4,800 bps. Simultaneous 2312.5 Hz and 1412.5 Hz tones for 60 milliseconds can indicate die bit rate will be a high rate, e.g., about 9,600 bps. The selection as to which bit rate to use for visual data transmission is based on a set of criteria tiiat is the most time efficient for the nature of the visual data that is to be sent, as will be described in more detail below. The subscriber's terminal 14 (Figure 12) uses these signals to get itself configured to receive the visual data at die bit rate that is selected by die agent's microcontroller 330 (Figure 13), as will also be described in more detail below. These tone patterns described above are also used each time the link is turned around after it is established initially, although it may be advantageous to increase the durations for the medium rate of about, 4,800 bps and die high rate of about 9,600 pbs speeds in order to compensate for the missing initial tones and flags. For example, tone durations of 188 milliseconds may be used for this purpose. The initial tone pair that was generated to notify die subscriber's terminal 14 tiiat visual data is coming and die follow-up flags, as described above, are not regenerated when die link is merely turned around, as opposed to establishing it in the first instance. After me last tones indicating die data transmission bit rates are transmitted, die agent's microprocessor 330 at the data link layer 214 (Figure 11) assumes that die data link has been established. Therefore, it reconfigures d e modem controller 346 (Figure 13) to set die data transmit device to die selected bit rate and to transmit the visual data, for example in ASCII code format, or in any otiier desired standard or nonstandard format, and it proceeds to send or transmit die visual data. This assumption mat die link has been established and proceeding immediately to send die visual data saves a substantial amount of time in most ordinary circumstances. If this assumption is wrong, and die data link was not established, for example, due to a momentary interruption in the connection, die data link layer 214 (i.e., die microcontroller 330) will use a "retry" procedure to repeat the above-described sequence one or more times, as will be described in more detail below. At die subscriber's terminal 14, as best seen in Figure 12, which is normally in die voice mode before visual data transmission is initiated by die agent, as described above, die pair of different frequency tones indicating die initiation of a voice data transmission is received. These initial tones, it may be recalled from die description above, tell die subscriber's terminal 14 that visual data is coming. That pair of tones, upon reaching contact A of directional coupler 226, via die telephone network 50, are transmitted to contact C, where tiiey are picked up by die modem IC 222 via die high pass filter 238 and limiter 240. The high pass filter 238 passes only high frequency signals, like this pair of tones, to eliminate low frequency noise from die subscriber's telephone 12 tiiat might get through die directional coupler 226, since the directional coupler device is not prefect in passing signals only from the outside source. The modem IC 222, as illustrated in Figure 12, has two energy or tone detectors 242, 244, which can be used for detecting die two-tone signal generated at die agent's terminal 100 that says visual data is coming. One tone detector 242 is tuned to die frequency of die first of the two tones, e.g. 2312.5 Hz, and die otiier tone detector 244 is tuned to the frequency of the second of die two tones, e.g., 2912.5 Hz. A modem controller 246 connected to die two tone detectors 242, 244 monitors tiiose tone detectors 242, 244, and when a preset threshold energy is detected from both of them, the controller 246 sends a signal to the microcontroller 230, thereby letting d e microcontroller 230 know that visual data is coining on the telephone line 52. An automatic gain control device 248 is provided in front of die energy or tone detectors 242, 244 to adjust the energy level or amplitude of incoming signals to keep the incoming signal level within limits acceptable to the tone detectors. At die same time, die limiter 240 is positioned in front of die automatic gain control 248 to place a high limit on the amplitude of signals transmitted dierethrough so that an extraneous noise burst or spike emanating from the subscriber's telephone 12 or anywhere else in the system that might get through die directional coupler 226 does not cause die automatic gain control to lower the energy level at die same time that die tones are coming from the agent's terminal 100. A speaker phone at me subscriber's location could be particularly problematic, for example, if it is picking up a loud background conversation while die tone signal is being transmitted. Pots and pans clanging in d e background or otiier loud noise sources also have the potential of causing problems, if they occur while die tones are being transmitted- Therefore, using tone frequencies that are high in die voice band (300 Hz to 3300 Hz), such as the 2312.5 Hz and 2912.5 Hz tones described above, in conjunction with die directional coupler 228, high pass filter 238, and limiter 240 helps to provide die robustness according to this invention at is required for die reliable detection of die initial tones for establishing the data transfer link. The high pass filter 238 prevents lower frequency signals from reaching me modem IC 222. Since much of die energy in voice signals is in these lower frequencies, die automatic gain control function 248 in die modem IC 222 is prevented from saturating and tiiereby inhibiting die detection of the desired tones. The limiter 240 is also important in preventing high amplitude (loud) signals from causing die automatic gain control function 248 in die modem IC 222 to saturate. Upon receiving the signal from the modem controller 246 that data is coming, as described above, die microprocessor 230 emits control signals via connections 250 and 252 to switch relays 220, 222, and 234 to die data mode, i.e., to the broken-line positions illustrated in Figure 12, tiiereby disconnecting the subscriber's telephone 12 from me telephone network 50 and telephone line 52. This disconnection is implemented so die subscriber will not hear the data stream, and noises from the subscriber's telephone 12 will not interfere widi d e data transmission or reception. At die same time, the microcontroller 230 also sends a signal via connection 254 to die local power supply/tone generator 232, which is now connected by relay switch 222 to d e subscriber's telephone 12. In this data mode, die local power supply/tone generator 232 powers d e subscriber's telephone and provides a pleasing tone or simulated voice message letting the subscriber know that his or her telephone 12 did not go dead and tiiat data is being transferred. After the 2-tone energy drops below the preset threshold, die microcontroller 230 reconfigures die HDLC or modem controller 246 to detect flag signals in die data receiver function 246 of modem IC 222, which is also connected dirough die data (broken line) mode of relay switch 220, connection 258, and summing device 260 thus to die telephone line 52. As described above, die agent's terminal 100 transmits a number of flags immediately after die initial tone pair signal to inform die microcontroller 230 in the subscriber's terminal 100 tiiat signals indicating transmission rate are coming next. As described below, tiiese initial flags are relatively short data streams, so they are usually transmitted initially at a low rate, such as the 300 b.p.s. described above. Therefore, the miscrocontroller 230 is programmed to instruct the modem controller 246 to initially set die data receiver function 256 to the low rate, e.g. 300 b.p.s. Upon receiving the signal from die controller 246 of modem IC 222 that die flag or flags have arrived, the microcontroller 230 resets or reconfigures die controller 246 to actuate its tone detector functions 242, 244 to detect die tones tiiat comprise me rate signal from the agent's terminal 100, e.g., 1412.5 Hz and 2312.5 Hz, because tiiose are die tone frequencies generated by die agent's terminal 100 to indicate the bit rate selected for the data transmission, as described above. It might be feasible in some circumstances to eliminate this flag notice function and program die microcontroller to look directly for the bit rate indicator tones after the initialization, which could be faster, but it also could compromise robustness in terms of reliability. To compensate, the tones for the 4,800 bps and 9,600 bps speeds should also have a longer duration, such as 188 milliseconds. The tone or tones indicating die bit rate for the data transmission are then received and detected by die controller 246 of the modem IC 222. The tones detected are then signaled to die microcontroller 230, which interprets mem to decipher the bit rate set by the agent's terminal, and die microcontroller 230 in turn instructs the modem controller 246 of modem IC 222 to set its data receive function 256 to tiie bit rate indicated by die tone signal. If the flags or rate tones are not detected, die microcontroller 230 returns die subscriber's terminal 14 circuit to voice mode, and me agent's terminal 100 will eventually retry to establish the data link, as will be described in more detail below. The data receive function 256 of the modem IC is die demodulator portion of the modem function. It receives data, including die visual data being transmitted by die agent's terminal 100. The controller 246 of the modem IC 222 checks good frame/bad frame sequences in the visual data received and, if die frames are good, send die visual data to die microcontroller 230. The microcontroller 230 men gatiiers the good frames of visual data until it gets a complete set and then sends them to subscriber's LCD display 20 or whatever other compatible display device at is being used. The microcontroller 230 is programmed to recognize when it receives a complete visual data set and whether it is the end or if it is supposed to give a response back to the agent's terminal 100. The controller 246 may also first store die visual data in memory for later retrieval along widi otiier received groups of visual data. When die end of die data transmission has been received, die microcontroller 230 turns the link around once in order to send an acknowledgement to the agent's terminal 100 that all of die frames were received. To do so, die microcontroller 230 instructs die modem controller 246 to set up die data transmit function 254 of the modem IC 222 for me appropriate transmission rate, as described in more detail below, and it sets up die tone generators 250, 252 to send an advance signal ahead of acknowledgement data to let the microcontroller 320 of me agent's terminal 100 know what bit rate will be used. The microprocessor 320 of the agent's terminal 100 uses tiiat rate signal to set up die data receive function 356 of the agent's modem IC 322 at the elected bit rate, similar to that process described above for the subscriber's terminal 14, so it can receive the acknowledgement data and send it to die agent's microcontroller 320. Initial start tones and flags do not have to be sent for this link turn around function for purposes of the acknowledgement. Once die acknowledgement is sent, die subscribers terminal 14 turns the link around and waits to receive a disconnect message from the agent's terminal. When the disconnect is received, or when a time limit is reached, die microcontroller 230 tears down die data link by outputting signals to the relay switches 220, 222, and 234 and to die local power source/tone generator 232 to switch them back to the voice mode. The microcontroller 230 men reconfigures die modem controller 246 to activate the tone detector functions 242, 244 of e modem IC 222 to detect data link initiation tones again, and finally it goes into an idle mode waiting for the next data link initiation tones. At die agent's terminal 100, the acknowledgement data is received by me data receive function 356 of die modem IC 322 via alternate connection 358 and summing device 260. It is demodulated and sent by die controller 346 to the microcontroller 330. The microcontroller 330 notes the receipt of die acknowledgement data, which indicates tiiat it does not have to initiate a retry. The microcontroller 330 turns around d e link and sends a disconnect message to the user's terminal 14, men the microcontroller 330 finishes tearing down die data link by outputting signals to the relay switches 320, 322, and 334 and to die local power source/tone generator 332 to return die agent's terminal 100 to the voice mode, i.e., to reconnect die telephone 62 to the telephone network 50. The microcontroller 330 can also be programmed to send signals to the agent's display interface or terminal 80 to display visual messages, such as "Data Transfer in Progress" during the link establishment and visual data transmit operations and "Data Transfer Complete" during the link tear down process. After the link tear down is complete, the microcontroller 330 goes into an idle mode, waiting for the next "send" signal initiated by die agent from die agent's keyboard or Windows display terminal 80. The block diagram in Figure 14 illustrates the high speed (9,600/4,800 bps) transmitter function steps utilized in me modem IC's 222 and 322 of die terminals 14 and 100. The data to be transmitted is digital at the input. It is fed into a scrambler step 420 for evening out die distribution of l's and O's, tiien into an encoder step 422 for breaking up the data into groups of bits suitable for modulation, through a modulator step 424 for conversion from digital to analog form, and tiien through a shaping fitter 426 for compensating for telephone network transmission characteristics. The result is an analog data signal that is transmitted via die telephone lines to die other terminal. By comparison, the low speed (300 bps) transmitter functions 254, 354 of modem IC's 222 and 322 are illustrated in Figure 15. The digital data goes only dirough an FSK (frequency shift keying) modulator for conversion from analog to digital form and a shaping fitter 430 for compensating for telephone network transmission characteristics for output in analog form to die telephone lines. The dual tone transmitter functions of the modem IC's 222 and 322 are illustrated in Figure 16- A digital control signal for the value of first tone frequency is fed from the controller 246 of 346 of the modem IC 222 or 322 to the tone generator 350 to generate the first tone at 2312.5 Hz. A level 1 digital signal is input at 432 for controlling the amplitude of die first tone. It is then fed dirough summing device 434 and dirough a low pass filter 435 for elimination of undesired frequency components. Likewise a digital control signal for the value of second tone frequency is fed from the controller 246 or 346 to the tone generator 352, which generates the 1412.5 Hz or 2912.5 Hz tone. A level 2 digital signal is applied at 438 for .controlling the amplitude of die second tone. The second tone is passed dirough die summing device 434 and low pass filter 436. The result is a single tone of eitiier frequency or botii tones simultaneously, as described above, for either initiating the link establishment procedure or setting die transmission speed. The low speed (300 bps) tone receiver function 242 or 342 of the modem IC's 222 or 322 is shown in Figure 17. This configuration of modem IC's 222 and 322 is used when receiving 300 pbs data or when detecting tones. When receiving tones, the received analog signal is passed dirough bandpass filter 440 to eliminate unwanted frequencies, then to variable gain element 442, which together widi automatic gain control 443, implements the automatic gain control 248, 348. The output of the variable gain element 442 feeds into tone detectors 450, 452, and 454, only two of which are used in die present implementation. The tone detectors produce a digital signal which indicates die presence or absence of die tone to which tiiey are tuned. When receiving 300 bps data die bandpass filter 440, variable gain element 442, and automatic gain control 443 operate as described above. The output of die variable gain element 442, feeds into FSK filter 444 where die data tones are filtered from die signal, then to timing recovery function 448 where die bit positions are identified, and to demodulator 446 where me data is recreated in digital form. The resulting data is sent to the controller of modem IC 222 and 322 for further processing- The high speed (9,600/4,800 bps) tone receiver 244 or 344 of modem IC's 222 or 322 is illustrated in Figure 18. This configuration of modem IC 222 and 322 is used when receiving 9600 bps or 4800 bps data. The received analog signal is passed dirough bandpass filter 440 to eliminate unwanted frequencies, then to variable gain element 442 which together with automatic gain control 443, implements the automatic gain control 248, 348. The output of die variable gain element 442 feeds into demodulator 458, timing recovery 462, and adaptive equalizer 460 where the signals are reduced to a decodable form, then to decoder 464 where the digital data is recovered, tiien to descrambler 466 where the originally transmitted data is separated from the scrambling sequence. The resulting data is sent to die controller of modem IC 222 and 322 for further processing. On die levels of die data link layer 214 ra application layer 216 of die agent's terminal 100 (Figure 11), the implicit link establishment procedure is best illustrated by die flow chart logic in Figure 19. The procedure to initiate link establishment begins in die application layer 216 (Figure 11) at the start step 400 (Figure 19) when the agent presses a key on die keyboard or clicks a mouse with die cursor on a Windows screen selection, thereby requesting that die visual data selected by e agent be transmitted to the subscriber's terminal. The data link layer 214 responds by instructing the physical layer 212 (Figure 11) to execute die link establishment procedure described above. The physical layer 212 changes die agent's terminal 100 from voice mode to data mode at step 402 (Figure 19), sets up the modem IC 322 (Figure 13) to generate the 2312.5 Hz and 2912.5 Hz initiate tones at step 404 (Figure 19), and sets up the modem IC 322 (Figure 13) to generate the six flags at 300 pbs at step 406 (Figure 19). In the next step 408, the data link layer 214 (Figure 11) selects the transmission speed to be used for sending die visual data to die subscriber's terminal 14. The criteria for transmission speed selection is basically that a short data stream with few characters can be sent more time efficiently by low transmission speeds that do not require as much time to prepare the link for transmission, such as echo canceler switching and die like, as to prepare for higher rate transmissions. For example, any data stream that is less than four characters is preferably transmitted at 300 bps. Any data stream that contains 4 or more characters is preferably transmitted at a transmission rate of 9,600 pbs (or 4,800 bps if that is die current speed. The implementation of die transmission speed selection according to this invention depends on the fact tiiat die protocol used requires the application layer 216 to terminate each data transmission with one of d e following control characters: EXT, ETB, or EOT. If the data link layer 214, specifically die microcontroller 330, received one of these control characters before receiving die predefined number of characters, i.e., 4, it sets up die transmission rate at 300 bps; otherwise, it sets up the transmission rate at 4,800 bps or 9,600 bps. Then, before initiating the data transmission, the microcontroller 330 sets up the modem IC 322 to generate die speed indicator tones at step 410, 412, or 414 for die subscriber's terminal 100, so it can set itself to receive data at die selected speed. Finally, the microcontroller 330 sets up the modem IC 322 at step 416; which ends die implicit link establishment procedure according to this invention. Transmission of the visual data at the selected speed tiien follows. The implicit link establishment functions of the data receiving terminal is shown in Figure 20. The visual data receiving terminal is considered to be die subscriber's terminal 14 for purposes of this description, but it could also be descriptive of die agent's terminal 100 under some circumstances. It starts at 470 with die assumption mat the circuit of terminal 14 is in the voice mode and the modem IC 222 is set to detect die 2312.5 Hz and 2912.5 Hz initializing tones. The first step 472 is for the microcontroller 230 to determine whether botii of die 2312.5 Hz and 2912.5 Hz tones were received by die modem IC 222. If not, die microcontroller 230 stays at idle. If so, die microcontroller 230 switches the terminal 14 from the voice mode to die data mode, as described above, at step 474. The microntroller 230 proceeds to die next step, 478 to set up die modem IC 222 to receive the data at 300 bps and to start a timer. The time is set to provide an outside limit for the microcontroller 230 to see transmission of the flags before it returns the terminal to voice made. Otherwise, a false signal that sounds like die initiating tone could cause a switch to die data mode and leave it locked tiiere waiting for the flags that never come. The microcontroller 230 then monitors receipt of the six data flags, and at step 480 it determines whetiier at least one of die flags have been received. If not, step 482 checks to see whether the time has run out. If not, it continues to wait. If so, it proceeds to step 404, where it changes die subscriber terminal back to the voice mode. On die other hand, if at least two flags are detected at step 480, tiien the microcontroller 230 sets up the modem IC 222 at step 486 to detect 2312.5 Hz and/or 2912.5 Hz tones generated by agent's terminal 100 to inform the terminal 14 as to what baud rate die following data will be transmitted. It also resets the outside time limit for detecting tiiose tones. The step 488 is where the microcontroller 230 finds tiiat eitiier me speed setting tones are detected or die time runs out. If the time runs out at step 488 with no speed tones detected, tiien it proceeds to step 484 where it changes terminal 14 back to die voice mode. On die otiier hand, if the speed tones are detected at step 488 before die time runs out, tiien the microcontroller 230 proceeds to set up the modem IC 222 to receive at either 300 bps (step 490), 4,800 bps (step 492), or 9,600 bps (step 494). Specifically, receipt of a single 1412.5 Hz tone causes a 300 bps set-up; a single 2312.5 Hz tone causes a 4,800 bps set-up; and a 1412.5 Hz tone togetiier with a 2312.5 Hz tone causes a 9,600 bps set-up. Once die modem IC 222 is set to receive the visual data at tiie selected speed, die link is established. After receiving die visual data, the microcontroller 230 in the subscriber's terminal 14 turns die link around to transmit the acknowledgement data to die agent's terminal 100 according to die procedure in Figure 21. Of course, having just received die visual data, die subscriber's terminal 14 is already in the data mode at die start 496 of die link turn around procedure. It first determines at step 500 which speed it will use to transmit the acknowledgement data according to the criteria discussed above. For a simple acknowledgement data transmission, which is usually very short, the 300 bps rate will probably be selected, so die modem IC 222 is set up at step 502 to transmit the single 2312.5 Hz tone for 188 ms to tell the agent's terminal that 300 bps will be the transmission speed. However, since the turn around link procedure may also be used for otiier purposes, or for transmitting back other and longer data, the steps 504 and 506 for setting up the modem IC 222 to transmit tones for 4,800 bps or 9,600 bps are also shown. Finally, after die speed tones are generated and sent, die microcontroller 230 proceeds to the final link turn around step 508 where it sets up d e modem IC 222 to send die acknowledgement data. For the otiier terminal, i.e., the agent's terminal 100, the link turn around procedure is illustrated in Figure 22. Essentially, as described above, after having sent the visual data, die microcontroller 330 of agent's terminal 100 sets up the modem IC 322 at step 510 to detect incoming speed tones at die 1412.5 Hz and 2312.5 Hz frequencies. It also starts the timer to measure the time elapsed from the set-up of die modem IC 322 until the speed tones are received. The microcontroller 330 at step 520 determines which tones were detected, tiius the speed of die acknowledgement data transmission coming. If the time has run out before this time, a failure is reported at step 516, which may initiate a retry or a return to the voice mode. However, if a single 1412.5 Hz tone is detected, step 522 sets the modem IC 322 to receive data at 300 bps. If a single 2312.5 Hz tone is detected, step 524 sets die modem IC 322 to receive data at 4,800 bps. If both 1412.5 Hz and 2312.5 Hz tones are received, step 526 sets the modem IC 322 to receive data at 9,600 bps. The data link is thereby completely turned around, and die agent's terminal 100 is ready to receive the acknowledgement or other data from the subscriber's terminal. The retry strategy, according to this invention, is illustrated in Figure 23. At step 528, the data link is established at maximum speed, according to die procedures illustrated in Figures 19 and 20, as described above. The maximum speed is 9,600 bps, which in this retry procedure is always the starting retry speed. However, it does not have to be set up tiiis way, so that retries at initial lower speeds can also be used, for example, if the preceding transmissions had resulted in reduced speed retries. For example, once the speed has been reduced during a call, it is likely that the lower speed will have to be used in subsequent transmissions anyway, so it may be better to start with the lower speed. In step 530, die block of data, such as die visual data, is sent by die agent's terminal 100, and die receiving terminal, such as die subscriber's terminal 14, after receiving the data turns the link around to send die acknowledgement data back to the agent's terminal 100, as shown in Figure 22 and described above. Also, as described above, die time is also set during die link turn around to indicate whetiier tiiere is a failure. If the transmit is a success at step 532, then the success is reported at 534, and ' die terminals 14 and 100 go back to voice mode. Success means tiiat die link turn around procedure of Figure 22 ended witiiout failure and die response received from die subscriber's terminal 14 indicates tiiat all data was received correctly. On the other hand, if a successful transmission is not determined at step 532, die retry procedures go to die next step 536 to query whether the number of retries has already reached a preset maximum, because it would be futile to continue retrying indefinitely to establish the data link and make a successful data transmission where it is obviously not working. If the maximum total retries have been reached at step 536, tiien failure is reported at 538, so die terminal can return to voice mode. However, if the maximum number of retries have not been reached at step 536, die next step 540 queries whetiier die number of retries at this particular speed has reached a preset maximum for tiiat speed. The purpose for this step is to allow a certain number of retries at the current transmission speed and tiien going to the next lower speed to retry a certain preset number of times at that speed, too. The idea is that a retry at lower speeds might work where higher speeds do not. If die maximum number of retries at a certain speed has been reached, at step 540, then the next step 542 determines whetiier there are any lower speeds available. In other words, is die retry already operating at the lowest 300 bps rate, or is it still at one of the higher 4,800 bps or 9,600 bps speeds. If it is already down to 300 bps, so tiiere is no lower speed available, then a failure is reported at 538 as before. However, if a lower speed is available, step 544 resets the modem IC transmission speed to the next lower speed, i.e., from 9,600 bps to 4,800 bps, or from 4,800 bps to 300 bps. Then the process continues to the next step 546 where a check is made to see whetiier die failure at step 532 was due to excessive time elapsed, again referring back to those time checks in the link turn around procedure in Figure 22. Of course, if the maximum retries at the particular speed in step 540 have not been reached, die process would go immediately to die time-induced failure check of step 546. If the failure at step 532 is determined at step 546 not to have been due to excessive time, the next step 548 is to turn the link around again, and tiien resend die data at step 550. Also at step 550, after die data has been resent, die link is turned around again, die time is restarted, and d e process is tiien returned at step 532 to see if die last retry at sending die data was a success. On die other hand, if die step 546 determines die failure was due to excessive time, step 552 skips the turn around step of 548 and goes dirough implicit link establishment and data send operations again. A failure which is not the result of time out occurs when die response received from the subscriber's terminal 14 indicates that not all the data was received correctly. A failure which is the result of time out occurs when the agent's terminal 100 receives no response at all from the user's terminal 14. Eventually, of course, this retry procedure will cycle enough to eitiier report a success at 534 or a failure at 538. In either instance, the ultimate result will be to return the systems to voice mode. The link tear down control utilized in this invention is shown in Figure 24, which is illustrated from the standpoint of the terminal that initiates die data transmission. Therefore, for the purposes of tiiis description, Figure 24 is used to illustrate the link tear down control in die agent's terminal 100 (Figure 11). It may be noted that the tear down control functions from the standpoint of die subscriber's terminal 14 (Figure 11) are essentially the same as those illustrated in Figure 24, except tiiat die word "send" would be replaced by the word -receive- and vice versa. The start step 560 means essentially that the agent executes the keystroke or clicks on the Window display tiiat sends die signal to the microcontroler 330 in the agent's terminal saying it wants to send down some data, such as the visual data to be transmitted to die subscriber's terminal 14. Upon receipt of this "send" signal, the microcontroller 330 proceeds to step 562 to establish the data link, which was described above and illustrated in Figure 19 and may include some or all of the retry procedure illustrated in Figure 23. With the data link established, die microcontroller 330 instructs the modem IC 322 at step 564 to send die data, such as die visual data, to die subscriber's terminal 14. In tiie protocol used in mis invention, die application layer 216 of the agent's terminal 100 must decide before the end of a data transmission whether no response, one response, or open-ended exchanges will be allowed. The term "response" as used for tiiis purpose means a response from the peer application layer 206 of the subscriber's terminal 14, not the normal acknowledgement data that die data link layers 204 and 214 exchange to insure data integrity. For example, no response may be selected for die usual case in which the agent transfers a screen of data to be viewed by d e subscriber, while one response might be appropriate for the agent who wishes to retrieve some information from the subscriber's terminal 14, such as die amount of memory space available. Open ended exchanges may be selected when die protocol is used between two agent-type terminals which are being used in a back-and-forth transaction. The protocol used in tiiis invention, therefore, requires the agent's application layer 216 to inform the data link layer 214 of die responses expected from the subscriber's application layer 206 by, for example, terminating each data transmission widi one of die following characters: ETX, ETB, or EOT. An ETX character is used to signal that an open-ended exchange is allowed. An ETB character indicates tiiat one response is allowed. An EOT character indicates tiiat no response is allowed. Therefore, the data link layer 214 of the agent's terminal 100 has to detect which response option, open ended (ETX), one response (ETB), or no response (EOT) has been selected and designated by the application layer 216 of the agent's terminal 100. This detection occurs in steps 566, 568, and 570 of tiie tear down control in Figure 24. In step 566, the microcontroller 330 checks the end of die data ttansmission tiiat comes down from the application layer 216 to see if it has an ETX character at die terminal end of die data. If so, the microcontroller 330 at die agent's terminal cannot tell whetiier die current data ttansmission that just ended was the last one expected in an exchange or whether it should expect responding data to come back from the subscriber's terminal 14. Therefore, it does not start to tear down die data link. Instead, it leaves die agent's terminal 100 in the data mode and waits to receive data from the subscriber's terminal 14. On the other hand, if die current data transmission coming from the agent's application layer 216 is not terminated widi an ETX character, the microcontroller 330 proceeds to die next step 568 to check for an ETB character, as wUl be described below. If die ETX character was detected at step 566 and d e data link is left intact, as described above, die next step 572 would be to receive the next data transmission from the subscriber's terminal 14. Since the subscriber's terminal 14 operates under d e same protocol as the agent's terminal 100, any data ttansmission received from die subscriber's terminal 14 by die agent's terminal 100 at step 572 also has to end with one of die characters ETX, ETB, or EOT. Therefore, the agent's microcontroller 330 can also tell from the data transmission received from the subscriber's terminal 14 whether the data link is to be torn down. Consequently, at step 574, the data received by agent's terminal 100 in step 572 from the subscriber's terminal 14 is checked by microcontroller 330 for the terminal character ETX. If ETX is present, then the microcontroller 330 still does not tear down die data link, and it leaves the agent's terminal 100 in the data mode ready to send more data, as determined by die application level 216. However, if the data received at step 572 does not terminate with an ETX, then the microcontroller 330 checks for an ETB in the next step 576. If an ETB is present, the indication is that the subscriber's terminal 14 expects to receive just one more response from the agent's terminal 100. Therefore, the microcontroller 330 keeps the agent's terminal 100 in the data mode for sending one more data ttansmission at step 580. However, if there is no ETB detected at step 576, die microcontroller 330 goes to die next step 578 and checks for the EOT character. If the EOT character is not present, the indicator is mat the end of the data ttansmission did not arrive. Therefore, die microcontroller 330 tears down die data link at step 584 to return to voice mode and reports an error at step 588 to die agent's display interface 80. However, if the EOT is detected at step 578, tiien the microcontroller 330 knows that nothing else is expected eitiier from or to the subscriber's terminal 14, so it tears down die data link at step 586 and reports a success to the agent's display interface 80. At the same time, the subscriber's terminal 14 would also have already torn down its data link and returned ' to die voice mode in response to tiiat same EOT character. Returning now to step 568, where the original data transfer by die agent's terminal 100 to the subscriber's terminal 14 did not have an ETX, the microcontroller 330 checks for the ETB character at the end of die data ttansmission. If the ETB is present, then one more response is expected from the subscriber's termmal 14, so the data link is left intact to receive that response. The expected one data response from the subscriber's terminal 14 is then received at step 582, and, upon receipt, the microcontroller 330 proceeds immediately to step 586 to tear down the link and return to voice mode. It also reports die successful data ttansfer at step 590 to the agent's display interface 80. Finally, if there was no ETB at step 568, the microcontroller 330 checks for EOT in the data ttansmission at step 570. If EOT is not detected, it tears down die link to return to voice mode at step 584 and reports the error at step 588 to the agent's display interface 80. However, if the EOT is detected at step 570, die microcontroller 330 tears down the link at step 586 to return to voice mode and reports a successful data transfer to the agent's display interface 80. As mentioned above, die subscriber's terminal 14 operates under die same protocol, so a separate description of die link tear down control for die subscriber's terminal 14 is not necessary. While die above description concentrates primarily on monodirection data transmission applications from an active agent to a passive user, because that is its primary purpose, it works equally as well in data ttansmission from either terminal, such as in bidirectional peer-to-peer data and voice communications. Also, the above description is a high level description to show die inventive concepts of this telecommunications system in a concise and understandable manner, as well as to enable persons skilled in tiiis art to practice the invention. There are, of course, many more details involved in implementing the invention that are common and known to persons skilled in this art, such as implementing the HDLC protocol, details of die modem IC's presenting a suitable interface to the user, controlling the host computer to terminal link, data compression techniques, and the like. The actual visual data transferred from die agent's terminal 100 to die subscriber's terminal 14 for visual display on die subscriber's screen or LCD 20 can be whatever data is displayed on the agent's computer display screen 64 and in the same format. However, it is preferable in many applications to transfer to the subscriber's terminal 14 only selected portions of die data displayed on die agent's screen 64 or to display die data in a different format or configuration on die subscriber's screen 20 from the way it appears on the agent's screen 64. For example, many computer applications or software programs are designed and written to create output information for certain classes of professionals. Such outputs or displays, while useful, are often complex and may contain mnemonics tiiat-are readtty understood by trained professionals, but which are not recognizable to lay persons, or they may contain certain data that is irrelevant to the subscriber along with relevant data that could beuseful to many subscribers. Such screen displays may be difficult for the lay person to interpret and use, or they might even contain some confidential data tiiat the agent would not want to disseminate to subscribers. One way to avoid tiiese problems, of course, would be to create the applications in the first place to display data in formats that are more useable to ordinary people. However, tiiat approach may be very limiting to the use of the telecommunications system of this invention, which is directed primarily to bring data from more sophisticated sources to lay persons in a simple visual format that can be read and understood readily. It would also not be economical, feasible, or perhaps even legal without obtaining appropriate permission, to modify existing application software used by die more sophisticated professionals to make it more suitable for display by lay persons. Therefore, this invention also includes a formatting feature in die application layer 216 of die agent's terminal 100 for capturing selected data from a screen display of another application data source and reformatting the captured data into anotiier display format, preferably more appropriate and easier for die subscriber or receiver to read and understand, before transmitting it to the subscriber's terminal 14. For purposes of this description, the screen display of data on the agent's terminal display device 64 from the original or originating application software is called the "source display", and die new, reformatted display of selected information captured from the source display is called die "target display". The reformatting application, according to tiiis invention, is used as illustrated in Figure 25. It assumes d e existence of some originating application that gathers and displays data for the agent on the agent's terminal display 64, such as information stored in a data base or available to a host computer 80, some of which the agent may wish to show to his or her customers or subscribers. Before displaying such information to the subscriber, however, the agent or the owner of die agent's station 60 (Figure 1), may want to reformat the display from the originating application and perhaps to eliminate some of the data from the display or add additional information, headings, addresses, dates, and die like. To do so, the agent or some administrator can call up tiie data onto his or her computer, which may be the agent's computer 64 or some other siπύlar device, with the originating application in a normal manner. In this manner, die agent or administrator acquires a sample data display 610 from that existing application on his or her computer screen. The agent or administrator tiien uses die reformatting application 600 according to this invention to capture selected data from die sample display 510 and apply selected reformatting rules from a set of such reformatting rules 602 that are stored in a structured file to create specific reformatting rules 604 that are to be applied to -data displays from the originating application whenever such data are to be sent to a subscriber. The custom specific reformatting rules 504 that are created for data displays from tiiat originating data application in the host computer 80 are then implemented in tiie agent's display computer 64. Therefore, when the agent is conversing with a customer or subscriber via tiieir telephones 12 and 62 and decides to show d e subscriber some data from a data base, such as data available through die host computer 80, the agent calls up the actual data widi die originating application 606, which is displayed on die agent's computer display 64 in its original format. When the agent initiates the "send" signal to transmit the data, die data display is automatically reformatted according to die specific reformatting rules 604 created for that kind of data display, before it goes to the agent's terminal 100 for ttansmission to the subscriber's terminal 14 via the telephone network 50, as described above. The data is, tiierefore, displayed on die subscriber's LCD or display screen 20 in die reformatted display. The reformatting function is application independent, as it uses die screen captured application's display to create the target display. Many computer applications have been designed and written to create output information for a certain class of professionals. The output formats are often complex, contain mnemonics, contain irrelevant data, and are difficult for a nonprofessional to interpret. Data ttansfer, according to this invention, provides for timely data ttansfer during normal telephone conversations, and die on-tiie-fly reformatting is a way of presenting quality information without the need to change the originating application. The reformatting is done by the routine tiiat is running in the sending computer 64. These routines are customized to die operating environment (PC-DOS, UNIX, PC-Windows, etc.) and run seemlessly (unobtrusively) as background tasks. These routines use sets of structured rules 502 previously created. The person assigned to create die specific reformatted output rule sets 604 uses a toolkit to create them. These are then copied to die agent's computers 64, 68 where the agent software is installed. When an existing application's output 606 is presented on d e computer's display, and the agent initiates a ttansfer of this information to a subscriber's terminal 100, this reformatting application identifies die data 606 displayed, locates the specific formatting rule set associated widi displays from that originating application, reformats the data from me display data 606, and tiien transfers the reformatted information to the subscriber's terminal 14. At the same time, the reformatted target display replaces die source display on die agent's computer screen 64, so the agent is looking at the same display as die subscriber. This reformatting application and toolkit 600 use the existing applications' source output formats and create a newly formatted target output for the targeted subscriber witiiout requiring time- consuming and expensive reprogramming of the existing applications. Using the toolkit does not require computer programming skills. When creating die reformatting rules, the effects of these reformatting rules can be reviewed during tiieir creation. When satisfied with die final presentation, as a result of applying the selected rule sets 602, the resulting specific reformatting rules 604 or structure information is available to ttansfer to the agent's computers 64, 68 that are designated for running the agent's software. This reformatting application 600 runs in a Window's environment, and it uses an actual, or a representative, source data display to create and review die specific reformatting rules 604. The toolkit 600 produces sets of specific rules 604 that are structured for high performance reformatting during tiie data-sending operation. These specific rules 504 are ordered according to an efficient and correct sequence of operations automatically by the toolkit 600, and witiiout requiring knowledge of die syntax of die structures . The target display is created from the representative source display 610 witiiin a Windows environment, similar to using a word processor. The correct rules are created by the toolkit using a unique design and set of algorithms, eliminating the need for direct programming and otiier editing interactions. These specific rules 604 are used during the data formatting operation, and they are applied to die application-produced screen displays. These structures are stored in three files, and in such a way so that the formatting application can use them with little additional processing. The set of commands used within the toolkit 600 to create the formatting rules is divided into two modes of use. One mode is to create a target display using copy operations for the text components within the source display. The otiier mode is to ttansfer the source display in its entirety to the target and then make modifications to it. The first method is used for report creations that involve many complex ttansformations. The second metiiod is used when the source screen is very close to acceptable for the target display and only a few minor clean-up actions are required. The specific structured rule sets 604 are applied to conditionally ttansfer, filter, enter, replace, or select textual components from die source display 606 for inclusion into the target display and to remove, replace, and enter text. Most of die commands are conditional. This means that if certain text (stting of characters) appears within a pre-selected range (rows and columns of the source display are identified for tiiese commands), tiien the requested action is taken- If the text is not found, tiien the associated action is not taken. An example of a command's action is to enter a character stting into a (relative) location in me target display. Anotiier example is: when a mnemonic is located witiiin a block of text in the source display, tiien enter a descriptive text string into tiie target display. The commands operate in a relative manner, based upon a starting location (the row and column of me source display is identified). Actions taken will be relative to the starting position (the selected row and column) for die target display. For example, if a mnemonic is located witiiin a block of the source display, die replacement description will be entered into die target at a row location relative to its starting row and at die column specified for the target. This allows a single formatting rule to be applied over a range of the source display and to correctly position die related information into the target screen. The example in Figure 26 demonstrates the action of two rules. The first rule enters the text stting "Start" into the target display 520 when the stting "ABC" is found witiiin the source display 522. The second rule enters the stting "End" into die target display 620 when die string "EFG" is found within the source display 622. The location (row and column) for the source display 522 is different from die target display's 620 row and column. The relative location for the text "Start" is maintained according to die position of "ABC" in the source display 622. Commands used in the reformatting application 600 locate the same text on a screen with a starting row and a column number along wi i the numbers of the rows and columns to use. This format defines a rectangular block on the screen display. The target screen display location is defined widi a row and a column position for the starting location of the block. A number of formatting commands or rules are available in the formatting application of this invention, including "Copy Text". Conditional or Replacement Copies", "Enter Text", "Remove a Block of Text," "Copy Entire Text", and "Remove Blank Lines". The "Copy Text" command wUl cause die reformatting application to copy a specified block 624 of die text from die source screen display 622 to die target screen display 520, as Ulusttated in Figure 27. The block 624 is defined on die source display screen 622 widi a mouse (or by entering the numbers of die rows and columns from the keyboard). The desired location for the block 624 for target screen display 620 is entered from the keyboard by column and row designations. The "Conditional or Replacement Copies" command causes a search for some specific text, mnemonic, or the like. If die search-for text is found within a specified block of die source display screen, tiien die reformatting application can do any of die following selected functions: (1) Copy the text to the target display; (2) Enter substitute text into the target, such as to replace a mnemonic with a more recognizable work; and (3) Enter an area of blanks on die display instead of die searched-for text, and the like. The "Enter Text" command allows tiie agent or administrator to enter a new literal stting or text, such as a heading, address, etc., into the target display tiiat was not in the source display, as illustrated in Figure 28. The "Remove a Block of Text" command causes die reformatting application to completely remove a selected block of text from die source display. This command is useful when the source display contains a block of irrelevant information or data tiiat the agent does not want die subscriber to see, whUe it allows other more relevant data to go from the source display into the target display. The "Copy Entire Text" command simply incorporates die entire source screen display into die target display (same row and column locations). The "Remove Blank Lines" command wuT move up lines in the target display, packing them into blank lines. This command may be used, for example, to fill up blanks in die target display that were created by die "Remove Block of Text" command described above. Of course, otiier commands can also be provided to help reformat source displays, once the principles of this invention are understood. Accordingly, a product and process are provided by tins invention in which existing voice telephone communications are augmented in a manner mat allows visual data reception and display by a passive subscriber or subscriber concurrent widi, and almost simultaneous widi, voice commumcation over a telephone line. The data ttansmission, as described above, is not technically simultaneous with voice communications, since there is a short voice disconnect and delay during data transmission, but die disconnect and automatic reconnect are so easily activated and used by die agent and almost completely passive to the subscriber or receiver, that it can almost be considered for practical purposes to be concurrent and simultaneous. One multiplexing arrangement compatible with public switched telephone network 50 is described above, however, any compatible multiplexing arrangement is possible. Accordingly, die foregoing is considered to be iUustrative only of the principles and of an exemplary embodiment of the invention. Further, since numerous modifications and changes will readily occur to tiiose skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the invention as defined by die claims which follow.

Claims: Claims The embodiment of die invention in which an exclusive property or privilege is claimed are defined as follows: 1. A telecommunication system for sequentially transmitting voice and visual communications via a plain old telephone system (POTS) connection, comprising: an agent station having agent visual data generating means for generating agent visual data and agent transfer means connected to said agent visual data generating means and to said POTS for receiving agent visual data from said agent visual data generating means and for transmitting said agent visual data into said POTS; and a subscriber station having subscriber visual data display means for displaying agent visual data from said agent station, a subscriber telephone, and subscriber ttansfer means connected to said subscriber visual data display means, to said subscriber telephone, and to said POTS for sequentially disconnecting said subscriber telephone from said POTS, receiving said agent visual data ttansmitted on said POTS by said agent transfer means, transmitting said agent visual data to said subscriber visual data display means, and tiien reconnecting said subscriber telephone to said POTS. 2. The telecommunication system of claim 1, wherein said subscriber ttansfer means includes: subscriber visual data receiving means for receiving said agent visual data and transmitting it to said subscriber visual data display means; subscriber directional coupler means positioned between said POTS , said subscriber telephone, and said subscriber visual data receiving means for transmitting signals bidirectionally between said POTS and said subscriber telephone, for transmitting signals from said POTS to said subscriber visual data receiving means, and for inhibiting signal ttansfer between said subscriber telephone and said subscriber visual data receiving means; and subscriber by-pass relay means positioned between said POTS and said subscriber directional coupler means for connecting and disconnecting said subscriber directional coupler and said subscriber telephone to and from said POTS and for by-pass connecting and disconnecting said subscriber visual data receiving means directly to said POTS. 3. The telecommunication system of claim 2, wherein said subscriber ttansfer means includes subscriber microcontroller means connected to said subscriber by-pass relay means for actuating said subscriber by-pass relay means to disconnect said subscriber directional coupler means and said subscriber telephone means from said POTS and to connect said subscriber visual data receiving means to said POTS when said agent visual data is being ttansmitted by said agent transfer means on said POTS. 4. The telecommunication system of claim 3 , wherein said agent transfer means includes agent tone generator means for generating signal tones on said POTS, including an agent start tone to indicate the agent visual data is about to be ttansmitted, and wherein said subscriber visual data receiving means includes subscriber modem means connected to said subscriber directional coupler means and to said subscriber microcontroller means for detecting said agent start tone and signaling said subscriber microcontroller means mat said agent start tone has been received, said subscriber microconttoUer means being programmed to actuate said subscriber by-pass relay means to disconnect said subscriber directional coupling means and said subscriber telephone from said POTS and to connect said subscriber visual data receiving means directly to said POTS in response to being signalled by said subscriber modem means that said agent start tone has been received. 5. The telecommunication system of claim 4, wherein said agent ttansfer means also includes agent flag signal generator means for generating agent flag signals, and wherein said agent tone generator means is also for generating agent rate signals including tone characteristics that are indicative of rate at which said agent transfer means will transmit said agent visual data on said POTS, said agent ttansfer means being programmed to put said agent flag signals on said POTS in advance of putting said agent rate signals on said POTS, and wherein said subscriber modem means includes subscriber modem controller means for receiving and demodulating said agent flag signals and feeding them to said subscriber microcontroller means, said subscriber microcontroller means being programmed to reconfigure said subscriber modem controller means in response to said agent flag signals to monitor said subscriber tone detector means to detect said agent rate signals. 6. The telecommunication system of claim 5, wherein said subscriber modem means is also for detecting said agent rate signals and for transmitting signals to said subscriber microcontroller means indicative of said tone characteristics of said agent rate signals, and wherein said subscriber microcontroller means is programmed to respond to said signals indicative of said tone characteristics and to generate signals to said subscriber modem controller means to set said subscriber modem means to receive data at die rate indicated by said tone characteristics. 7. The telecommunication system of claim 6, wherein said subscriber modem means is set up to receive and demodulate said agent visual data and to send demodulated visual data to said subscriber microcontroller means, and wherein said subscriber microcontroller means is programmed to receive said demodulated agent visual data, to form the demodulated agent visual data into sets, to transmit the sets of demodulated agent visual data to said subscriber visual data display means, and to recognize the end of a transmission of agent visual data. 8. The telecommunication system of claim 7, wherein said subscriber transfer means includes subscriber local disconnectrelay means positionedbetween said subscriber directional coupler means to and from said subscriber telephone for connecting and disconnecting said subscriber directional coupler means to and from and said subscriber telephone means, and wherein said subscriber local disconnectrelay means is connected to said subscriber microprocessor means and said subscriber microprocessor means is programmed to actuate said subscriber local disconnect relay means to disconnect said subscriber directional coupler means from said subscriber telephone in response to said agent start tone on said POTS. 9. The telecommunication system of claim 8, wherein said subscriber ttansfer means includes subscriber local power supply/tone generator means connected to said subscriber local disconnect relay means for providing local power and local audio tone to said subscriber telephone when said subscriber local disconnect relay means is actuated to disconnect said subscriber telephone from said POTS. 10. The telecommunication system of claim 7, wherein said subscriber visual data receiving means includes subscriber high pass filter means positioned between said subscriber directional coupler means and said subscriber modem means for establishing a low frequency limit and for blocking frequencies lower than said low frequency limit from reaching said subscriber modem means. 11. The telecommunication system of claim 10, wherein said subscriber visual data receiving means includes subscriber limiter means for establishing a high amplitude limit and for prohibiting signal amplitudes higher than said high amplitude limit from reaching said subscriber modem means. 12. The telecommunication system of claim 11, wherein said subscriber modem means includes subscriber automatic gain control means positioned between said subscriber limiter means and said subscriber tone detector means for adjusting amplitude of signals within limits acceptable to said subscriber tone detector means. 13. The telecommunication system of claim 12, wherein said subscriber transfer means includes subscriber isolation relay means connected to said subscriber microcontroller and positioned between said subscriber directional coupler means and said subscriber high pass filter means for isolating said subscriber modem means from said subscriber directional coupler means, said subscriber microcontroller being programmed to actuate said subscriber isolation relay means to isolate said subscriber modem means from said subscriber directional coupler means when said agent start tone is detected on said POTS. 14. The telecommunication system of claim 12, wherein said subscriber visual data receiving means includes subscriber summing means positioned between said subscriber high pass filter means and said subscriber limiter means and between said subscriber by-pass relay means and said subscriber limiter means for connecting said subscriber modem means to said subscriber by-pass relay means. 15. The telecommunication system of claim 14, wherein said subscriber by-pass relay means has a default mode in which said subscriber directional coupler means is connected to said POTS when said subscriber by-pass relay is not powered, and wherein said subscriber local disconnect relay means has a default mode in which said subscriber telephone is connected to said subscriber directional coupler means when said subscriber local disconnect relay means is not powered. 16. The telecommunication system of claim 14, wherein said subscriber isolation relay means has a default mode in which said subscriber modem means is connected to said subscriber directional coupler means when said subscriber isolation relay means is not powered. 17. The telecommunication system of claim 7, wherein said subscriber modem means includes subscriber data transmitting means for transmitting a subscriber acknowledgement signal to said agent station upon receipt of said agent visual data by said subscriber station. 18. The telecommunication system of claim 17, wherein said agent ttansfer means includes: agent modem means for modulating said agent visual data from said agent visual data generating means and sending die modulated visual data into said POTS, for modulating said agent flag signals and sending said agent flag signals into said POTS, and for generating tones for use as said agent start tone and for use as said agent rate signals; and agent microcontroller means connected to said agent modem means for generating said agent flag signals, for controlling actuation and deactuation of said agent modem means to modulate and send said agent flag signals, and for controlling actuation and deactuation of said agent modem means to generate and send said agent start tone and said agent rate signals. 19. Thetelecommunicatϊon system of claim 18, wherein said agent modem means includes first agent tone generator means for producing a tone having a first frequency and second agent tone generator means for producing a tone having a second frequency, and wherein said subscriber modem means includes first subscriber tone detector means for detecting a tone having said first frequency and second subscriber tone detector means for detecting a tone having said second frequency. 20. The telecommunication system of claim 19, wherein said agent microcontroller means is programmed to actuate said first agent tone generator and said second agent tone generator simultaneously to produce simultaneous tones having said first frequency and said second frequency, respectively, to comprise said agent start tone. 21. The telecommunication systems of claim 20, wherein said first frequency and said second frequency are both in the range of about 300 to 3,300 Hz. 22. The telecommunication system of claim 21, wherein said first frequency is about 2,312.5 Hz. 23. The telecommunication system of claim 21, wherein said second frequency is about 2,912.5 Hz. 24. The telecommunication system of claim 21, wherein said second frequency is about 1,412.5 Hz. 25. The telecommunication system of claim 20, wherein said start tone has a duration of about 200 milliseconds. 26. The telecommunication system of claim 20, wherein said agent microcontroller means comprises said agent flag signal generator means and is programmed to actuate said agent modem means to modulate and ttansmit data after said agent modem means produces said agent start signal and then sequentially to produce said agent flag signal for modulation and ttansmission by said agent modem means. 27. The telecommunication system of claim 26, wherein said agent modem means and said subscriber modem means botii have selectable low, medium, and high data ttansmitting and receiving rates. 28. The telecommunication system of claim 27, wherein said low data ttansmitting and receiving rate is about 300 bits per second. 29. The telecommunication system of claim 27, wherein said medium data ttansmitting and receiving rate is about 4,800 bits per second. 30. The telecommunication system of claim 27, wherein said high data ttansmitting and receiving rate is about 9,600 bits per second. 31. The telecommunication system of claim 27, wherein said agent microcontroller is programmed to actuate said agent modem means for ttansmitting said agent flag signals at said low rate. 32. The telecommunication system of claim31, wherein said flag signal includes six bytes of data. 33. The telecommunication system of claim 32, wherein a byte of said flag signal comprises a 01111110 byte. 34. The telecommunication system of claim 31, wherein said subscriber microcontroller means is programmed to actuate said subscriber modem means to receive and demodulate date in response to said agent start signal. 35. The telecommunication system of claim 34, wherein said subscriber microcontroller means is programmed to actuate said subscriber modem means to receive and demodulate data at said low rate in response to said agent start signal. 36. The telecommunication system of claim 35, wherein said agent microcontroller means is programmed to reconfigure said agent modem means after said agent flag signals are ttansmitted to produce and ttansmit said agent rate signal on said POTS. 37. The telecommunication system of claim 36, wherein said subscriber microcontroller means is programmed to reconfigure said subscriber modem means in response to said agent flag signals on said POTS to actuate said first and second subscriber tone detector means. 38. The telecommunication system of claim 37, wherein said agent microcontroller means is also connected to said agent visual data generating means and is programmed to reconfigure said agent modem means immediately after said agent rate signal is produced for data modulation and transmission on said POTS at a rate that is the same as the rate indicated by said agent rate signal and to then immediately feed said agent visual data from said agent visual data generating means to said modem means for modulation and transmission on said POTS. 39. The telecommunication system of claim 38, wherein said subscriber microcontroller means is programmed to reconfigure said subscriber modem means in response to said agent rate signal on said POTS to receive data at the rate indicated by said agent rate signal. 40. The telecommunication system of claim 39, wherein said subscriber microcontroller means is programmed to receive said agent visual data on said POTS via said subscriber modem means and to feed said agent visual data to said subscriber visual display means. 41. The telecommunication system of claim 40, wherein said agent visual data generating means is programmed to produce an agent termination character at the end of each agent visual data. 42. The telecommunication system of claim 41, wherein said subscriber microcontroller means is programmed to recognize said agent termination character as being indicative of die end of said agent visual data and to generate a subscriber acknowledgement signal in response to said agent termination character and to send said subscriber acknowledgement signal to said subscriber modem means for modulation and ttansmission on said POTS. 43. The telecommunication system of claim 42, wherein said subscriber microcontroller means is also programmed to generate a success report in response to said agent termination character for display on said subscriber visual data display means. 44. The telecommunication system of claim 42, wherein said subscriber microcontroller means is also programmed to recognize when said agent termination character is not at the end of said agent visual data received by said subscriber ttansfer means and to generate an error report for display on said subscriber visual data display means. 45. The telecommunication system of claim 42, wherein said subscriber microcontroller means is programmed to reconfigure said subscriber modem means in response to said agent termination character to generate and ttansmit on said POTS a subscriber rate signal that is indicative of said low rate, tiien to reconfigure said subscriber modem means again to ttansmit data at said low rate, and to produce said subscriber acknowledgement signal in data form to said subscriber modem means for transmission on said POTS. 46. The telecommunication system of claim 41, wherein said subscriber microcontroller means is programmed to select said low data ttansmitting and receiving rate when said agent visual data is shorter than a threshold data lengtii and to select a data ttansmitting and receiving rate at is faster than said low data ttansmitting and receiving rate when said agent visual data is at least as long as said threshold data length. 47. The telecommunication system of claim 46, wherein said threshold data length is about four characters. 48. The telecommunication system of claim 46, wherein said data ttansmitting and receiving rate that is faster than said low data ttansmitting and receiving rate is said medium data transmitting and receiving rate. 49. The telecommunication system of claim 46, wherein said data transmitting and receiving rate that is faster than said low data transmitting and receiving rate is said high data transmitting and receiving rate. 50. The telecommunication system of claim 46, wherein said agent microcontroller means is programmed to detect said agent termination character, to determine tiie length of said agent visual data preceding said agent termination character, to compare the length of said agent visual data to said threshold data lengdi, and to actuate said agent modem means to produce said agent rate signal that is indicative of the selected data ttansmitting and receiving rate. 51. The telecommunication system of claim 50, wherein said agent rate signal comprises a single tone generated by said first agent tone generator means having said first tone frequency to indicate said low data ttansmitting and receiving rate. 52. The telecommunication system of claim 50, wherein said agent rate signal comprises a single tone generated by said second tone frequency to indicate said medium data ttansmitting and receiving rate. 53. The telecommunication system of claim 50, wherein said agent rate signal comprises simultaneous tones generated by botii said first and said second agent tone generator means having both said first and said second tone frequencies to indicate said high data ttansmitting and receiving rate. 54. The telecommunication system of claim 35, wherein said subscriber microcontroller means is programmed with a time limit and is programmed to determine whetiier said agent flag signals are received by said subscriber modem means within said time limit from when said subscriber microcontroller means reconfigures said subscriber modem means to receive data and, if not, to return said subscriber station to a voice mode by outputting signals to actuate said subscriber by-pass relay means, said subscriber local disconnect relay means, and said subscriber isolation relay means to reconnect said subscriber telephone to said POTS, to disconnect said subscriber visual data receiving means from said POTS, and to disconnect said subscriber local power supply /tone generator means from said subscriber telephone. 55. The telecommunication system of claim 37, wherein said subscriber microcontroller means is programmed widi a time limit and is programmed to determine whether said agent rate signal is received by said subscriber modem means witiiin said time limit from when said subscriber microcontroller means reconfigures said subscriber modem means to actuate first and second subscriber tone detector means and, if not, to return said subscriber station to a voice mode by outputting signals to actuate said subscriber by-pass relay means, said subscriber local disconnect relay means, and said subscriber isolation relay means to reconnect said subscriber telephone to said POTS, to disconnect said subscriber visual data receiving means from said POTS, and to disconnect said subscriber local power supply/tone generator means from said subscriber telephone. 56. The telecommunication system of claim 45, wherein said agent modem means is also for detecting subscriber rate signals on said POTS and for distinguishing characteristics of subscriber rate signals tiiat are indicative respectively of said low, medium, and high data ttansmitting and receiving rates, and for signaling said agent microcontroller means in a manner that reflects said rate distinguishing characteristics of the subscriber rate signals detected. 57. The telecommunication system of claim 56, wherein said agent microcontroller means is programmed to reconfigure said agent modem means immediately after ttansmitting said agent visual data for detecting a subscriber rate signal on said POTS. 58. The telecommunication system of claim 57, wherein said agent microcontroller means is programmed to recognize die rate distinguishing characteristics of the subscriber rate signals and to reconfigure said agent modem means to receive said acknowledgement signal data at die data transmitting and receiving rate indicated by said subscriber rate signal. 59 - The telecommunication system of claim 57, wherein said agent microcontroller means is programmed widi a maximum acknowledgement time limit and to measure time elapsed from said reconfiguring of said agent modem means for detecting said subscriber rate signal, and wherein said microcontroller means is also programmed to initiate a retry procedure when said time elapsed exceeds said maximum acknowledgement time limit by resending said agent start signal, said agent flag signals, and said agent visual data in sequence to said subscriber station and tiien to reconfigure again said agent modem means for detecting said subscriber rate signal. 60. The telecommunication system of claim 59, wherein said agent microconttoUer means is programmed to reconfigure said agent modem means to ttansmit said agent visual data at a first retry rate at least as high as the rate at which said agent visual data was ttansmitted initially for a predetermined number of said retry procedures. 61. The telecommunication system of claim 60, wherein said agent microcontroller means is programmed to reconfigure said agent modem means to transmit said agent visual data a predetermined number of times at a second retry rate lower than said first retry rate if none of said retries at said first retry rate result in receipt of said subscriber rate signal by said agent modem means, and to reconfigure said agent modem means after each such retry at said second retry rate for detecting said subscriber rate signal and to terminate said retry procedure whenever said subscriber rate signal is detected by said agent modem means. 62. The telecommunication system of claim 61 , wherein said agent microcontroller means is programmed to terminate said retry procedure when said agent visual data has been ttansmitted at said low data ttansmitting and receiving rate a preset number of times without detecting said subscriber rate signal. 63. The telecommunication system of claim 41, wherein said subscriber station includes subscriber visual data generating means connected to said subscriber microcontroller means for generating subscriber visual data, said subscriber visual data being programmed to produce an agent termination character at die end of each subscriber visual data. 64. The telecommunication system of claim 63, wherein said agent termination character and said subscriber termination character is any one of die characters ETX, ETB, EOT, wherein said ETX character signals tiiat an open-ended exchange of data is allowed between said agent station and said subscriber station, said ETB character signals that one data response is allowed from said subscriber station, and said EOT character indicates that no data response from said subscriber station is allowed. 65. The telecommunication system of claim 64, wherein said agent microcontroller means is programmed to detect and distinguish whetiier said agent termination character is an ETX, ETB, or EOT, character. 66. The telecommunication system of claim 65, wherein said agent microcontroller means is programmed to reconfigure said agent modem means to detect a subscriber rate signal on said POTS in response to an ETX character after said agent visual data is ttansmitted and tiien to reconfigure said agent modem means in response to said subscriber rate signal to receive subscriber visual data from said subscriber station on said POTS at the rate indicated by said subscriber rate signal. 67. The telecommunication system of claim 66, wherein said agent microcontroller means is programmed to determine whether said subscriber termination character at tiie end of said subscriber visual data is an ETX character, and, if it is an ETX character, then to leave said agent modem means configured to ttansmit data. 68- The telecommunication system of claim 67, wherein said agent microcontroller means is programmed to determine whetiier said subscriber termination character at the end of said subscriber visual data is an ETB character, if it is not an ETX character, and if it is an ETB character, then to leave said agent modem means configured to ttansmit data. 69. The telecommunication system of claim 68 wherein said agent microcontroller means is programmed to determine whetiier an EOT character is present at the end of said subscriber visual data, if an ETB character is not detected, and, if not, to terminate data ttansfer and reception by said agent station. 70. The telecommunication system of claim 69, wherein said agent microcontroller means is programmed to terminate data ttansfer and reception by said agent station if an EOT character is detected at the end of said subscriber visual data. 71. The telecommunication system of claim 70, said agent visual data generator means is programmed to produce one additional agent visual data after said ETB character at the end of said subscriber visual data is detected, and wherein said agent microcontroller means is programmed to cause said agent modem means to transmit said additional agent visual data on said POTS and tiien to terminate said data ttansfer and reception by said agent station, while said subscriber microcontroller means is programmed to reconfigure said subscriber modem means to receive said additional agent visual data and ttansfer it to said subscriber visual display means and tiien to convert the subscriber station to a subscriber voice mode. 72. The telecommunication system of claim 71, wherein said agent microcontroller means is programmed to reconfigure said agent modem to receive data in response to detection of said ETB character at the end of said agent visual data, said subscriber microcontroller means is programmed to reconfigure said subscriber modem means to ttansmit one additional subscriber visual data and tiien to convert the subscriber station to a subscriber voice mode, and said agent microcontroller means is programmed to terminate data transfer and reception by said agent station after reception of said additional subscriber visual data. 73. The telecommunication system of claim 72 , wherein said agent microcontroller means is programmed to terminate data transfer and reception by said agent station when said EOT character is not detected at die end of said agent visual data. 74. The telecommunication system of claim 73 , wherein said agent microcontroller means is programmed to terminate data transfer and reception by said agent station when said EOT character is detected at die end of said agent visual data. 75. The telecommunication system of claim 74, wherein said subscriber station is in said subscriber voice mode when said subscriber ttansfer means is disconnected from said POTS and said subscriber telephone is connected to said POTS. 76. The telecommunication system of claim 75, wherein said agent microcontroller means is programmed to convert said subscriber station to said subscriber voice mode by outputting signals to acmate said subscriber by-pass relay means to connect said subscriber directional coupler and said subscriber telephone to said POTS and to disconnect said subscriber visual data receiving means from said POTS, to acmate said subscriber local disconnect relay means to connect said subscriber telephone to said subscriber directional coupler means and to disconnect said subscriber telephone from said subscriber local power supply/tone generator means, and to acmate said subscriber isolation relay means to connect said subscriber modem means to said subscriber directional coupler means. 77. The telecommunication system of claim 76, wherein said agent station includes agent visual data display means for displaying said agent visual data and said subscriber visual data. 78. The telecommunication system of claim 77, wherein said agent station includes an agent telephone connected to said agent transfer means. 79. The telecommunication system of claim 78, wherein said agent ttansfer means includes: agent directional coupler means positioned between said POTS, said agent telephone, and said agent modem means for transmitting signals bi-directionally between said POTS and said agent telephone, for transmitting signals from said POTS to said agent modem means, and for inhibiting signal ttansfer between said agent telephone and said agent modem means; and agent by-pass relay means positioned between said POTS and said agent directional coupler means for connecting and disconnecting said agent directional coupler and said agent telephone to and from said POTS and for by-pass connecting and disconnecting said agent modem means directly to said POTS. 80. The telecommunication system of claim 79, wherein said agent microconttoUer means is connected to said agent by-pass relay means for actuating said agent by-pass relay means to disconnect said agent directional coupler means and said agent telephone means from said POTS and to connect said agent modem means to said POTS when said subscriber visual data is being transmitted by said subscriber ttansfer means on said POTS. 81. The telecommunication system of claim 80, wherein said subscriber ttansfer means includes subscriber tone generator means for generating signal tones on said POTS, including a subscriber start tone to indicate die subscriber visual data is about to be ttansmitted, and wherein said agent modem means is connected to said agent directional coupler means and to said agent microcontroller means for detecting said subscriber start tone and signaling said agent microcontroller means that said subscriber start tone has been received, said agent microcontroller means being programmed to acmate said agent by-pass relay means to disconnect said agent directional coupling means and said agent telephone from said POTS and to connect said agent modem means directly to said POTS in response to being signalled by said agent modem means tiiat said subscriber start tone has been received. 82. The telecommunication system of claim 81, wherein said subscriber transfer means also includes subscriber flag signal generator means for generating subscriber flag signals, and wherein said subscriber tone generator means is also for generating subscriber rate signals indicative of rate at which said subscriber ttansfer means will ttansmit said subscriber visual data on said POTS, said subscriber transfer means being programmed to put said subscriber flag signals on said POTS in advance of putting said subscriber rate signals indicative of rate on said POTS, and wherein said agent modem means includes agent modem controller means for receiving and demodulating said subscriber flag signals and feeding diem to said agent microcontroller means, said agent microcontroller means being programmed to reconfigure said agent modem controller means in response to said subscriber flag signals to monitor said agent tone detector means to detect subscriber rate signals indicative of the rate at which said subscriber ttansfer means will ttansmit said subscriber visual data on said POTS. 83. The telecommunication system of claim 82, wherein said agent modem means is also for detecting said subscriber rate signals and for ttansmittmg signals to said agent microconttoUer means indicative of said tone characteristics of said subscriber rate signals, and wherein said agent microcontroller means is programmed to respond to said signals indicative of said tone characteristics and to generate signals to said agent modem controller means to set said agent modem means to receive data at the rate indicated by said tone characteristics. 84. The telecommunication system of claim 83, wherein said agent modem means is set up to receive and demodulate said subscriber visual data and to send demodulated visual data to said agent microcontroller means, and wherein said agent microcontroller means is programmed to receive said demodulated subscriber visual data, to form the demodulated subscriber visual data into sets, and to ttansmit the sets of demodulated subscriber visual data to said agent visual data display means, and to recognize die end of a ttansmission of subscriber visual data. 85. The telecommunication system of claim 84, wherein said agent transfer means includes agent local disconnect relay means positioned between said agent directional coupler means and said agent telephone for connecting and disconnecting said agent directional coupler ' means to and from said agent telephone, wherein said agent local disconnect relay means is connected to said agent microprocessor means, and wherein said agent microprocessor means is programmed to acmate said agent local disconnect relay means to disconnect said agent directional coupler means from said agent telephone in response to said subscriber start tone on said POTS . 86. The telecommunication system of claim 85, wherein said agent transfer means includes agent local power supply/tone generator means connected to said agent local disconnect relay means for providing local power and local audio tone to said agent telephone when said agent local disconnect relay means is actuated to disconnect said agent telephone from said POTS. 87. The telecommunication system of claim 86, wherein said agent ttansfer means includes agent high pass filter means positioned between said agent directional coupler means and said agent modem means for establishing a low frequency limit and for blocking frequencies lower than said low frequency limit from reaching said agent modem means. 88. The telecommunication system of claim 87, wherein said agent visual data receiving means includes agent limiter means for establishing a high amplitude limit and for prohibiting signal amplitudes high than said high amplitude limit from reaching said agent modem means. 89- The telecommunication system of claim 88, whereinsaid agent modem means includes agent automatic gain control means positioned between said agent limiter means and said agent tone detector means for adjusting amplitude of signals within limits acceptable to said agent tone detector means. 90. The telecommunication system of claim 89, wherein said agent ttansfer means includes agent isolation relay means connected to said agent microcontroller means and positioned between said agent directional coupler means and said agent high pass filter means for isolating said agent modem means from said agent directional coupler means, said agent microconttoUer means being programmed to acmate said agent isolation relay means to isolate said agent modem means from said agent directional coupler means when said subscriber start tone is detected on said POTS. 91. The telecommunication system of claim 90, wherein said agent ttansfer means includes agent summing means positioned between said agent high pass filter means and said agent limiter means and between said agent by-pass relay means and said agent limiter means for connecting said agent modem means to said agent by-pass relay means. 92. The telecommunication system of claim 91, wherein said agent by-pass relay means has a default mode in which said agent directional coupler means is connected to said POTS when said agent by-pass relay means is not powered, and wherein said agent local disconnect relay means has a default mode in which said agent telephone is connected to said agent directional coupler means when said agent local disconnect relay means is not powered. 93. The telecommunication system of claim 92, wherein said agent isolation relay means has a default mode in which said agent modem means is connected to said agent directional coupler means when said agent isolation relay means is not powered. 94. The telecommunication system of claim 93, wherein said agent modem means includes agent data ttansmitting means for ttansmitting an agent acknowledgement signal to said subscriber station upon receipt of said subscriber visual data by said agent station. 95. The telecommunication system of claim 1, wherein said agent station includes recorded voice information means connected to said agent ttansfer means and to said agent visual data generating means for generating artificial voice messages on said POTS and for actuating said agent visual data generating means to generate said agent visual data. 96. The telecommunication system of claim 95, wherein said recorded voice information means includes an audiotex system. 97. The telecommunication system of claim 95, wherein said recorded voice information means includes a voice mail service. 98. The telecommunication system of claim 79, wherein said agent telephone is in the form of automatic answering means for responding to a telephone ring signal on said POTS and going off-hook on said POTS and recorded voice information means connected to said automatic answering means and to said agent visual data generating means for generating artificial voice messages on said POTS and for actuating said agent visual data generating means to generate said agent visual data. 99. The telecommunication system of claim 98, wherein said automatic answering means and said recorded voice information means include an audiotex system. 100. The telecommunication system of claim 98, wherein said automatic answering means and said recorded voice information means include a voice mail service. 101. The telecommunication system of claim 1, whereinsaid subscriber visual display means includes a visual display screen capable of producing visual images from electronic data. 102. The telecommunication system of claim 1, wherein said subscriber visual display means includes a computer with a visual display terminal. 103. The telecommunication system of claim 1, wherein said subscriber visual display means includes a printer. 104. The telecommunication system of claim 101, wherein said subscriber visual display means includes modem means for detecting a telephone ring signal on said POTS and going-off hook and random access memory means for receiving and storing said agent visual data for later delivery to said display screen. 105. The telecommunication system of claim 101, including an automatic answering and voice recording machine connected to said subscriber ttansfer means for automatically going off-hook in response to a telephone ring signal on said POTS and for recording voice communications on said POTS. 106. The telecommunication system of claim 1, wherein said subscriber visual display means includes an agent computer with source data generating means for generating a source display of visual source data, and reformatting means for capmring designated portions of said source display and for converting the capmred portions into a target display of said agent visual data, which target display has different visual content and appearance tiian said source display. 107. The telecommunication system of claim 106, wherein said agent visual data generating means includes agent visual data display means connected to said agent computer for displaying said source display in a visually perceptible manner, and wherein said agent computer includes a data interface port connected to said agent ttansfer means, an interface circuit for feeding said agent visual data to said data interface port and to said agent ttansfer means, and agent send actuating means for actuating said reformatting means capture said designated portions of said source display and to convert diem to said target display and for actuating said interface circuit to feed said target display as agent visual data to said agent ttansfer means. 108. The telecommunication system of claim 107, wherein said reformatting means is actuateable to copy data in designated portions of said source display and to insert said data into designated portions of said target display. 109. The telecommunication system of claim 108, wherein said reformatting means includes conditional criteria for comparing to data in said designated portions of said source display and screening means for prohibiting copying of data that does not meet said conditional criteria into said target display. 110. The telecommunication system of claim 108, wherein said reformatting means includes conditional criteria for comparing to data in said designated portions of said source display and to substimte character strings for insertion into said target display instead of said data in said designated portions of said source display tiiat meet said conditional criteria. 111. The telecommunication system of claim 110, wherein said agent computer includes auxiliary agent data entry means for entering additional data into said target display tiiat is not in said source display. 112. The telecommunication system of claim 111, wherein said auxiliary agent data entry means includes a keyboard connected to said agent computer. 113. A method of establishing a data ttansfer link between a first electronic telecommunication station and a second telecommunication station for transmitting information data between said first and second stations, comprising the steps of: establishing a telecommunication connection between said first station and said second station by which data can be ttansmitted; generating a start tone at said first station and transmitting said start tone to said second station via said telecommunication connection; selecting a data transmission rate at said first station at which said information data will be transmitted from said first station to said second station, generating a data ttansmission rate signal at said first station that has characteristics indicative of die selected data ttansmission rate, and transmitting said rate signal to said second station via said telecommumcation connection; transmitting said information data from said first station to said second station at said selected data ttansmission rate via said telecommumcation connection after ttansmitting said data ttansmission rate signal; monitoring said telecommunication connection at said second station for detection of said start tone, and, when said start tone is on said telecommunication connection, detecting said start tone at said second station; and detecting and receiving said data ttansmission rate signal, determining said selected data ttansmission rate from said characteristics indicative of the selected data ttansmission rate, and preparing said second station to receive said information data at said selected data transmission rate. 114. The method of claim 113, including tiie steps of: generating a flag signal at said first station after ttansmitting said start and ttansmitting said flag signal to said second station at a present flag signal rate via said telecommunication connection; preparing said second station in response to said start tone to receive said flag signal at said present flag signal rate; and monitoring said telecommunication connection for said flag signal. 115. The method of claim 114, including die steps of establishing a flag signal time limit, starting a timer at said second station in response to detection of said start tone at said second station and measuring time elapsed after detection of said start tone, comparing said time elapsed after detection of said start tone to said flag signal time limit, determining if said time elapsed after detection of said start tone equals said flag signal time limit without having received said flag signal, and, if so, returning said second station to a mode of monitoring said telecommunication connection for detection of said start tone. 116. The method of claim 114, including die steps of receiving said flag signal at said second station, and, in response to said flag signal, preparing said second station to detect and receive said data transmission rate signal. 117. The method of claim 116, including the steps of receiving said flag signal, and, in response to said flag signal, preparing said second station for detecting and receiving said data transmission rate signal. 118. The method of claim 113, including die steps of generating said start tone by generating a first start tone component widi a first frequency and a second start tone component widi a second frequency, and ttansmitting said first start tone component and said second start tone component simultaneously to said second station via said telecommunication connection. 119. The method of claim 118, including tiie steps of generating said first start tone - component and said second start tone component widi botii of said first frequency and said second frequency within a range of about 300 to 3,300 Hz. 120. The method of claim 119, including die step of generating said first start tone component with a frequency of about 2,312.5 Hz. 121. The method of claim 119, including the step of generating said second start tone component with a frequency of about 2,912.5 Hz. 122. The method of claim 119, including die step of generating said second start tone component with a frequency of about 1,412.5 Hz. 123. The method of claim 115, including tiie steps of generating a plurality of short flag signals sequentially at said first station and returning said second station to said mode of monitoring said telecommunication connection for detection of a start tone when a preset threshold number of said flag signals is not detected at said second station with said flag signal time limit. 124. The method of claim 123, including die steps of generating six flag signals sequentially a said first station and returning said second station to said mode of monitoring said telecommunication connection for detection of a start tone when at two of said flags are not detected at said second station within said flag signal time limit. 125. The method of claim 116, including die steps of generating a plurality of flag signals sequentially at said second station, establishing a flag signal time limit, measuring time elapsed after detection of said start tome and comparing the measured time elapsed to said flag signal time limit, and preparing said second station to detect and receive said data ttansmission rate signal when a threshold number of said flag signals are detected at said second station within said flag signal time limit. 126. The method of claim 125, including die steps of generating six flag signals at said first station and preparing said second station to detect and receive said data ttansmission rate signal when two of said flag signals are detected at said second station within said flag signal time limit. 127. The method of claim 114, including die step of establishing said preset flag signal rate at about 300 bits per second. 128- The method of claim 113 or 117, including the steps of generating said data transmission rate signal at said first station in the form of a tone with a characteristic frequency that indicates die selected data ttansmission rate. 129. The method of claim 128, including tiie steps of establishing a low data transmission rate, a medium data ttansmission rate tiiat is faster than said low data ttansmission rate, and a high data ttansmission mat is faster than said medium data transmission rate. 130. The method of claim 129, including die step of establishing said low data ttansmission rate at about 300 bits per second. 131. The method of claim 129, including the step of establishing said medium data ttansmission rate at about 4,800 bits per second. 132. The method of claim 129, including establishing said high data transmission rate at about 9,600 bits per second. 133. The method of claim 129, including die step of establishing a maximum low speed data length, determining the acmal length of said information data, comparing the acmal length of said information data to said maximum low speed data length, selecting said low data ttansmission rate when said acmal length of said information data does not exceed said maximum low speed data length, and, alternatively, selecting one of said data ttansmission rates that is higher than said low data transmission rate when said acmal length of said information data exceeds said maximum low speed data length. 134. The method of claim 133, including the step of establishing said maximum low speed data length at four characters. 135. The method of claim 133, including me step of returning said second station to said mode of monitoring said telecommunication connection for detection of a start tone, if said data transmission rate signal is not detected at said second station witiiin a predetermined length of time. 136. The method of claim 135, including the steps of preparing said first station to receive and detect an acknowledgment signal via said telecommunication connection from said second station after transmitting said information data, and monitoring said telecommunication connection for said acknowledgement signal. 137. The method of claim 136, including the steps of establishing an acknowledgement time limit, measuring the time after ttansmitting said information data at said first station, and, if an acknowledgement signal is not received witiiin said acknowledgement time limit, and performing a retry process by repeating said steps at said first station of selecting a data transmission rate, transmitting said information data, preparing to receive and detect an acknowledgement signal, and monitoring said telecommunication connection for said acknowledgement signal. 138. The method of claim 137, including the step of selecting a slower data ttansmission rate in said retry process than was selected previously. 139. The method of claim 137, including the steps of selecting the same data ttansmission rate in said retry process as was selected previously and repeating said retry process a predetermined number of times at said previously selected data transmission rate or until an acknowledgement signal is detected at said first station, and, if no acknowledgement signal is received witiiin said predetermined number of times, then selecting the next slower data transmission rate and repeating said retry process again for said predetermined number of times until an acknowledgement signal is detected, and, if no acknowledgement signal is detected at said first station during any retry at said next slower data transmission rate said predetermined number of times or until an acknowledgement signal is detected at said first station. 140- The method of claim 139, including die steps of returning said first station to an idle mode at comprises the steps of monitoring said telecommunication connection for a start signal from said second station and simultaneously remaining ready for repeating said metiiod of establishing a data transfer link upon receipt of a link establishment command signal. 141. The method of claim 136, including die steps of generating an acknowledgement signal at said second station and ttansmitting said acknowledgement signal via said telecommumcation connection to said second station. 142. The method of claim 136, including tiie steps of preparing said first station to receive and detect a data transmission rate signal after ttansmitting said information data, generating and transmitting a data ttansmission rate signal at said second station indicative a rate at which said second station will ttansmit an acknowledgement signal, detecting said data ttansmission rate signal at said first station, setting said first station to receive said acknowledgement signal, generating said acknowledgement signal at said second station and ttansmittmg said acknowledgement signal at the rate indicated by said data ttansmission rate signal via said telecommunication connection to said first station, and receiving said acknowledgement signal at said first station. 143. The method of claim 142, including the step of generating said data ttansmission rate signal in die form of a tone having a frequency that is indicative of a data ttansmission rate. 144. The method of claim 142, including d e steps of generating said data ttansmission rate signal in the form of two distinct, simultaneous frequencies that together indicate a data transmission rate. 145. The method of claim 142, including the steps of generating said acknowledgement signal in me form of a data stting. 146. The method of claim 141, including die steps of generating a termination character at the end of said information data. 147. The method of claim 146, including die step of detecting said termination character at said first station and utilizing it to determine the length of said information for said step of selecting said data ttansmission rate. 148. The method of claim 141, including the steps of detecting said termination character at said second station to determine when die end of die information data is received by said second station, and generating said acknowledgement signal in response to said detecting of said termination character at said second station. 149. The method of claim 146, including the step of generating said termination character in the format of one of the following: ETX to indicate that open-ended exchange of data is allowed; ETB to indicate that one data response is allowed; and EOT to indicate that no data response is allowed. 150. The method of claim 149, including die steps of detecting said ETX termination character at said first station, setting said first station to receive data from said second station, detecting said ETX termination character at said second station, and setting said second station to ttansmit data. 151. The method of claim 150, including die steps of generating another information data with one of said termination characters, ttansmitting said another information data from said second station, receiving said another information data at said first station, detecting said termination character at the end of said another information data, generating an acknowledgement signal at said first station, ttansmitting said acknowledgement signal via said telecommunication connection to said second station. 152. The method of claim 149, including d e steps of detecting said ETB termination character at said first station, setting said first station to receive data from said second station, detectmg said ETB termination character at said second station, and setting said second station to ttansmit data. 153. The method of claim 152, including die steps of generating another information data with one of said termination characters, transmitting said another information data from said second station, setting said second station to receive an acknowledgement signal, receiving said another information data at said first station, detecting said one of said termination characters at the end of said another information data at said first station, generating an acknowledgement signal at said first station, transmitting said acknowledgement signal to said first station in idle in response to said ETB termination character by setting said first station to receive and detect a start signal, detecting said acknowledgement signal at said second station, and setting said second station in idle in response to said ETB termination character by setting said second station to receive and detect a start signal. 154. The method of claim 149, including the steps of detecting said EOT termination character at said first station, setting said first station to receive said acknowledgement signal, detecting said EOT termination character at said second station, generating said acknowledgement signal at said second station , ttansmitting said acknowledgement signal to said first station, setting said second station in idle in response to said EOT termination character by setting said second station to receive and detect a start signal, receiving and detecting said acknowledgement signal at said first station, and setting said first station in idle in response to said EOT termination character by setting said first station to receive and detect a start signal. 155. The method of claim 154, including tiie steps of connecting a telephone to said telecommunication connection with a relay switch that is controllable by said first station, acmating said relay switch to disconnect said telephone from said telecommunication connection when generating and transmitting said start tone at said first station, acmating relay switch to reconnect said telephone to said telecommunication connection when setting said first station in idle. 156. The method of claim 154, including die steps of connecting a second telephone to said telecommumcation connection with a relay switch that is controllable by said second station, acmating said relay switch to disconnect said telephone from said telecommunication connection in response to receipt and detection of said start tone by said second station, and acmating said relay switch to reconnect said telephone to said telecommumcation connection when setting said second station in idle. 157. The method of Claim 113, including die steps of capmring said information data from a formatted screen source display, of data produced by a source computer application, utilizing the capmred information data to create a formatted screen target display, and ttansmitting the information data from the first station to the second station in the target display format. 158. The method of Claim 157, including the steps of capmring said information data from a formatted screen source display by selecting portions, and transferring the selected portions to the target display. 159. The method of Claim 158, including die steps of selecting specific positions on the target display for positioning specifically identifiable portions of the data captured from the source display. 160. The method of Claim 159, including the step of creating a set of reformatting rules specificaUy applicable to an identified source computer application display format, which reformatting rules designate specific portions of the source display to be captured, specific positions and arrangements for setting the captured portions of the source display into die target display, storing said reformatting rules in a computer memory at the first station, retrieving and interposing said reformatting rules between the source display and said first station, selecting die source display for ttansmission to said second station, and automatically applying the reformatting rules to the selected source display to create die information data in the format of the target display along widi die step of ttansmitting the information data.

Inventors: BRITTAIN ANTHONY J, DAVIS RICHARD A, FETTE CHARLES J, MATHYS PETER, WITMORE RONALD K, BRITTAIN, ANTHONY, J., DAVIS, RICHARD, A., FETTE, CHARLES, J., MATHYS, PETER, WITMORE, RONALD, K.
Applicants: RADISH COMMUNICATIONS SYSTEMS, RADISH COMMUNICATIONS SYSTEMS, INC.
Application year: 1993
Main classification: H04M11
IPC codes: H04M11, H04N7