Patent Publication Number: US-9432442-B2

Title: System and method for a graphics terminal multiplier

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Stage filing under 35 U.S.C. 371 from International Patent Application Ser. No. PCT/US2010/051215, filed Oct. 1, 2010, and published on Apr. 7, 2011 as WO 2011/041744A1, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/248,274 filed Oct. 2, 2009 (“SYSTEM AND METHOD FOR A GRAPHICS TERMINAL MULTIPLIER”), the contents of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to the field of thin-client systems. In particular, but not by way of limitation, the present invention discloses techniques for implementing a multiplier for thin-client terminal systems. 
     BACKGROUND 
     Centralized computer systems with multiple terminal systems for accessing the centralized computer systems were once the dominant computer system architecture. These initially very expensive mainframe or mini-computer systems were shared by multiple computer users wherein each computer user had access to a terminal system coupled to the mainframe computer. 
     In the late 1970s and early 1980s, semiconductor microprocessors and memory devices allowed the creation of inexpensive personal computer systems. Personal computer systems revolutionized the computing industry by allowing each individual computer user to have access to their own full computer system. Each personal computer user could run their own software applications and did not need to share any of the personal computer&#39;s resources with any other computer user. 
     Although personal computer systems have become the dominant form of computing, there has been a resurgence of the centralized computer system model wherein multiple computer users access a server system using individual computer terminals. Computer terminal systems can have significantly reduced maintenance costs since computer terminal users cannot easily introduce computer viruses into the main computer system or load other unauthorized computer programs. Terminal based computing also allows multiple users to easily share the same set of software applications. 
     Modern personal computer systems have become increasingly powerful over the decades such that a modern personal computer system is more powerful than the mainframe and mini-computer systems of the 1970&#39;s. In fact, modern personal computer systems are so powerful that the vast majority of the computing resources in modern personal computer systems generally sit idle when a typical computer user uses a modern personal computer system. Thus, personal computer systems can now easily serve multiple computer users. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals describe substantially similar components throughout the several views. Like numerals having different letter suffixes represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG. 1  illustrates a diagrammatic representation of machine in the example form of a computer system within which a set of instructions, for causing the machine to perform any one or more of the methodologies discussed herein, may be executed. 
         FIG. 2A  illustrates a block diagram of a first example embodiment of a thin-client terminal system coupled to a thin-client server computer system. 
         FIG. 2B  illustrates a high-level block diagram of the example embodiment of the single thin-client server computer system of  FIG. 2A  supporting multiple individual thin-client terminal systems using multi-conductor wire that includes analog signals and electrical power, in accordance with an example embodiment. 
         FIG. 3A  illustrates a block diagram of a second example embodiment of a thin-client terminal system coupled to a thin-client server computer system using a purely digital communication line. 
         FIG. 3B  illustrates a high-level block diagram of the example embodiment of the single thin-client server computer system of  FIG. 3A  supporting multiple individual thin-client terminal systems using a local area network, in accordance with an example embodiment. 
         FIG. 3C  illustrates a high-level block diagram of the example embodiment of the single thin-client server computer system of  FIG. 3A  supporting multiple individual thin-client terminal systems using a universal serial bus connection. 
         FIG. 4A  illustrates a block diagram of an example embodiment of a thin-client multiplier that couples the thin-client server computer system of  FIG. 3A  to more than one thin-client terminal systems of the example embodiment of  FIG. 2A . 
         FIG. 4B  illustrates a high-level block diagram of the example embodiment of the thin-client server computer system of  FIG. 3A  coupled by a computer network connection to the example embodiment of the thin-client multiplier of  FIG. 4A  for supporting multiple individual thin-client terminal systems from the embodiment of  FIG. 2A . 
         FIG. 4C  illustrates a high-level block diagram of the example embodiment of the thin-client server computer system of  FIG. 3A  coupled via a universal serial bus connection to the example embodiment of the thin-client multiplier of  FIG. 4A  for supporting multiple individual thin-client terminal systems from the embodiment of  FIG. 2A . 
         FIG. 4D  illustrates a high-level block diagram of the example embodiment of the thin-client server computer system of  FIG. 3A  coupled via a universal serial bus connection to the example embodiment of the thin-client multiplier of  FIG. 4A  for supporting multiple individual thin-client terminal systems from the embodiment of  FIG. 2A . 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show illustrations in accordance with example embodiments. These embodiments, which are also referred to herein as “examples,” are described in enough detail to enable those skilled in the art to practice the invention. It will be apparent to one skilled in the art that specific details in the example embodiments are not required in order to practice the present invention. For example, although the example embodiments are mainly disclosed with reference to a thin-client system, the teachings can be used in other environments. The example embodiments may be combined, other embodiments may be utilized, or structural, logical and electrical changes may be made without departing from the scope what is claimed. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope is defined by the appended claims and their equivalents. 
     In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. Furthermore, all publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls. 
     Computer Systems 
     The present disclosure concerns computer systems.  FIG. 1  illustrates a diagrammatic representation of machine in the example form of a computer system  100  that may be used to implement portions of the present disclosure. Within computer system  100  there are a set of instructions  124  that may be executed for causing the machine to perform any one or more of the methodologies discussed herein. In a networked deployment, the machine may operate in the capacity of a server machine or a client machine in client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing a set of computer instructions (sequential or otherwise) that specify actions to be taken by that machine. Furthermore, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. 
     The example computer system  100  includes a processor  102  (e.g., a central processing unit (CPU), a graphics processing unit (GPU) or both), a main memory  104  and a static memory  106 , which communicate with each other via a bus  108 . The computer system  100  may further include a video display adapter  110  that drives a video display system  115  such as a Liquid Crystal Display (LCD) or a Cathode Ray Tube (CRT). The computer system  100  also includes an alphanumeric input device  112  (e.g., a keyboard), a cursor control device  114  (e.g., a mouse or trackball), a disk drive unit  116 , a signal generation device  118  (e.g., a speaker) and a network interface device  120 . 
     The disk drive unit  116  includes a machine-readable medium  122  on which is stored one or more sets of computer instructions and data structures (e.g., instructions  124  also known as ‘software’) embodying or utilized by any one or more of the methodologies or functions described herein. The instructions  124  may also reside, completely or at least partially, within the main memory  104  and/or within the processor  102  during execution thereof by the computer system  100 , the main memory  104  and the processor  102  also constituting machine-readable media. 
     The instructions  124  may further be transmitted or received over a computer network  126  via the network interface device  120 . Such transmissions may occur utilizing any one of a number of well-known transfer protocols such as the well known File Transport Protocol (FTP). 
     While the machine-readable medium  122  is shown in an example embodiment to be a single medium, the term “machine-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies described herein, or that is capable of storing, encoding or carrying data structures utilized by or associated with such a set of instructions. The term “machine-readable medium” shall accordingly be taken to include, but not be limited to, solid-state memories, optical media, and magnetic media. 
     For the purposes of this specification, the term “module” includes an identifiable portion of code, computational or executable instructions, data, or computational object to achieve a particular function, operation, processing, or procedure. A module need not be implemented in software; a module may be implemented in software, hardware/circuitry, or a combination of software and hardware. 
     The Resurgence of Terminal Systems 
     Before the advent of the inexpensive personal computer, the computing industry largely used mainframe or mini-computers that were coupled to a plurality of “dumb” terminal systems. Such terminal devices are referred to as “dumb” terminals since the computing ability resided within the mainframe or mini-computer, and the terminal device merely displayed an output screen and accepted alpha-numeric input. No user applications executed locally on the terminal system. Computer operators shared the mainframe computer among multiple individual computer users that each used individual terminals coupled to the mainframe computer. These terminal systems generally had very limited graphics capabilities and were generally capable of visualizing only alpha-numeric characters on the display screen of the terminal system. 
     With the introduction of the modern personal computer system, the use of dumb terminals largely disappeared since personal computer systems were much more cost effective. When the services of a dumb terminal were required to interface with a legacy terminal-based computer system, a personal computer system could easily execute a terminal emulation program that would emulate the operations of a dumb terminal at a cost very similar to the cost of a dedicated dumb terminal. Thus, a single system could operate as both a personal computer system and a terminal to a larger terminal-based computer system. 
     During the personal computer revolution, personal computers introduced high resolution graphics and cursor control devices (such as the computer mouse) to personal computer users. The combination of high-resolution graphics displays and cursor control devices allowed for much more intuitive computer user interfaces than a primitive text-only display screen. For example, virtually all current personal user interface systems now use multiple windows, icons, and pull-down menus that are implemented with high resolution graphics and navigated with a cursor control device. Furthermore, high-resolution graphics allowed for applications that used photos, videos, and graphical images. 
     In recent years, a new generation of high-resolution graphics terminal systems have been introduced into the computer market as people have rediscovered some of the advantages of terminal-based computing systems. For example, computer terminals allow for greater security and reduced maintenance costs since users of computer terminal systems cannot easily introduce computer viruses by downloading or installing new software into the computer system. Thus, with a centralized computer system having multiple terminals, only the main centralized computer server system needs to be closely monitored and maintained. The stateless terminal systems require almost no maintenance at all. The new generation of computer terminal systems includes high-resolution graphics capabilities, audio output, and cursor control system input (e.g., mouse, trackpad, trackball) that all personal computer users have become accustomed to using. 
     Modern terminal-based systems allow multiple users at individual high-resolution terminal systems to share a single personal computer system and all of the application software installed on that personal computer system. In this manner, a modern high-resolution terminal system is capable of delivering nearly the full functionality of a personal computer system to multiple users without the cost, power, and the maintenance requirements of an individual personal computer system for each user. One category of these modern terminal systems is called “thin-client” systems since the terminal systems are a “client” to main server system and the terminal systems designed to be very simple and limited (thus “thin”) and thus primarily depend on a thin-client server system for application processing activities. A thin-client terminal system thus mainly focuses only on conveying input and output between the user and the centralized server system. 
     A First Thin-Client System Example Embodiment 
       FIG. 2A  illustrates a block diagram of a first embodiment of a thin-client environment. In the thin-client environment of  FIG. 2A , a server computer system  220  is illustrated as being coupled to one (of possibly many) thin-client terminal system  240 . The thin-client server computer system  220  and thin-client terminal system  240  are coupled with a multi-conductor wire  230  that carries input from a user of the thin-client terminal system  240  to the server computer system  220  and output from the server computer system  220  to the thin-client terminal system  240 . 
       FIG. 2B  illustrates a conceptual diagram of the server computer system  220  from  FIG. 2A  providing computer processing resources to a plurality of individual thin-client terminal systems  240 . A single thin-client server computer system  220  is coupled to several individual thin-client terminal systems  240  in a hub &amp; spoke arrangement since the example embodiment of  FIG. 2A  is illustrated as a direct connection between the thin-client server computer system  220  and each of the thin-client terminal systems  240 . The individual thin-client terminal systems  240  are served using thin-client server network software  297  running on thin-client server computer system  220 . 
     Referring back to  FIG. 2A , the goal of thin-client terminal system  240  is to provide most or all of the standard input and output features of a personal computer system to the user of the thin-client terminal system  240 . However, this goal is to be achieved with as low of a cost as possible. To reduce costs, the thin-client terminal system  240  will not provide application software or the full computing resources of a personal computer system within thin-client terminal system  240 . Instead, those features will be provided by the thin-client server system  220  that will interact with the thin-client terminal system  240 . Thus, the thin-client terminal system  240  merely acts as an input and output device for the thin-client server computer system  220   
     In the thin-client embodiment of  FIG. 2A , the thin-client terminal system  240  acts largely as a simple pass through system such that most of the hardware for driving the thin-client terminal system  240  actually resides within the server computer system  220 . This type of thin-client architecture allows the actual thin-client terminal devices  240  in the implementation of  FIG. 2A  to be a very inexpensive. 
     In the embodiment of  FIG. 2A , a thin-client interface system  210  is responsible for interacting with all of the attached thin-client terminal systems  240 . To generate video output for each thin-client terminal system  240 , a thin-client video subsystem  214  in the server system  220  maintains a screen buffer  215  for each of the thin-client terminal systems  240 . Video display circuitry within the server system  220  reads the screen buffer  215  contents and drives an analog video output  221  for each thin-client terminal system  240 . Relatively simple video circuitry  265  in the thin-client terminal system  240  passes the analog video output signal to a video display monitor  267 . Audio may be handled in a similar manner wherein a thin-client audio system  212  generates analog audio output  222  for each of the thin-client terminal systems  240 . In the embodiment of  FIG. 2A , the analog audio information is also passed from audio circuitry  272  to the video display monitor  267 . In an alternate embodiment, the thin-client audio system  212  may pass a digital auto signal to the thin-client terminal system  240  which is then decoded and demodulated by the audio circuitry  272  into an analog audio signal at the thin-client terminal system  240 . 
     Input from the thin-client terminal systems  240  is handled using an input control system  281  that receives input information from a keyboard  283  (coupled to a keyboard connector  282 ) and a mouse  286  (coupled to a mouse connector  285 ). The input control system  281  encodes the user input information (e.g., keystrokes and mouse movements) and passes that user input information to a thin-client input interface system  211  in the server system  220 . In one particular embodiment, the design of the thin-client terminal systems  240  is so efficient that each thin-client terminal system  240  receives all of its needed electrical power from a power out conductor  223  in the multi-conductor wire  230 . 
     On the server side, the thin-client server computer system  220  is equipped with multi-user software for interacting with multiple thin-client terminal systems. As illustrated in  FIG. 2A , a thin-client interface system  210  within thin-client server system  220  supports the thin-client terminal system  240  as well as any other thin-client terminal systems (not shown) coupled to thin-client server system  220 . Each thin-client terminal system  240  may have its own dedicated screen buffer  215  within the thin-client video subsystem  214  in the thin-client server system  220 . 
     The thin-client terminal system  240  embodiment of  FIG. 2A  is a very efficient embodiment that requires a very minimal amount of hardware within the actual thin-client terminal system  240  located at the user location. Most of the difficult aspects of providing terminal service, such as the generation of a video signal to drive video display system  267 , are performed within the server system  220  wherein the power supply systems, bus infrastructure, and operating system support of the server system  220  can be used to help perform these tasks associated with providing terminal service. In this manner, the thin-client terminal system  240  is relatively simple and thus very inexpensive to produce. However, the particular thin-client embodiment of  FIG. 2A  does have some drawbacks. One drawback is that since the embodiment of  FIG. 2A  uses an analog video signal to transmit video information from the server system  220  to the individual thin-client terminal systems  240 , the length of the multi-conductor wire  230  must be kept relatively short. If too long of a multi-conductor wire  230  is used, the analog signal may not be sufficiently strong to generate high quality video at the thin-client terminal system  240 . 
     A Second Thin-Client System Example Embodiment 
       FIG. 3A  illustrates a high-level block diagram of a second example embodiment of a thin-client server computer system  320  coupled to one (of possibly many) thin-client terminal system  340 . The thin-client server computer system  320  and thin-client terminal system  340  are coupled via a bi-directional digital communications channel  330  that may be a serial data connection, an Ethernet connection, a wireless connection based on a wireless communication standard, such as the IEEE 802.11 standard, or any other suitable bi-directional digital communication means. 
       FIG. 3B  illustrates a conceptual diagram of a thin-client environment using the system of  FIG. 3A . Referring to  FIG. 3B , a single thin-client server computer system  320  provides computer services using thin-client server network software  397  to many different thin-client terminal systems  340 . In the example embodiment disclosed in  FIG. 3B , each of the individual thin-client terminal systems  340  is coupled to the thin-client server computer system  320  using local area network  330  such as Ethernet as a bi-directional communication channel. In such an embodiment, each of the individual thin-client terminal systems  340  will generally require its own individual power supply that is coupled to a power source such as an AC line current. 
       FIG. 3C  illustrates an alternate conceptual diagram of a thin-client environment using the thin-client architecture of  FIG. 3A . In  FIG. 3C , a single thin-client server computer system  320  provides computer services to many different thin-client terminal systems  340  using a serial bus system, such as the Universal Serial Bus (USB), as a bi-directional communication channel. In such an embodiment, a Universal Serial Bus hub  398  may be used to help couple more thin-client terminal systems  340  and extend the physical distance from the thin-client server computer system  320  where thin-client terminal systems  340  can be located. Additionally, in the event that a local area network is not available or feasible, the serial bus system used to connect the thin-client server computer system  320  to thin-client terminal systems  340  may emulate or provide an alternate option to the local area network for connecting the thin-client server computer system to the thin-client terminal systems. 
     As set forth in the previous section, the goal of any thin-client terminal system (such as thin-client terminal system  340 ) is to provide most or all of the standard input and output features of a personal computer system to the user of the thin-client terminal system  340 . However, this goal is to be achieved without providing the full computing resources or software of a personal computer system within thin-client terminal system  340  since those features will be provided by the thin-client server system  320  that will interact with the thin-client terminal system  340 . In the embodiment of  FIG. 3A , the thin-client terminal system  340  is more sophisticated and thus more costly than the thin-client terminal system  240  of  FIG. 2A . For example, the thin-client terminal system  340  is tasked with generating a video signal locally, and the thin-client terminal system  340  is responsible for providing its own operating power. Despite including these features, each thin-client terminal system  340  is still far more primitive than a full personal computer system and thus much less expensive than a personal computer system. 
     Referring to the block diagram of  FIG. 3A , the thin-client terminal system  340  provides both visual and auditory output using a high-resolution video display system to drive display system  367  and an audio output system to drive an audio output signal, respectively. In general, the thin-client terminal system  340  may have its own power supply  353  since most digital communication lines  330  do not provide power. 
     The high-resolution video generation system of thin-client terminal system  340  consists of thin-client control system  350 , a frame decoder  361 , a screen buffer  360 , and a video adapter  365 . The thin-client control system  350  identifies packets with video information and directs that video information to frame decoder  361 . The frame decoder  361  decodes digital video information from the associated thin-client screen buffer  315  in the server and places that digital video information into screen buffer  360  thus making screen buffer  360 . Screen buffer  360  contains a copy of the bit-mapped display in thin-client screen buffer  315 . Video adapter  365  reads the video display information out of screen buffer  360  and generates a video display signal to drive display system  367 . The screen buffer  360  is filled with video display information provided by thin-client control system  350  using video information sent as output  321  by the thin-client server system  320  across bi-directional digital communications channel  330 . Specifically, the video frame encoder  317  in the thin-client server system  320  sends information from a thin-client screen buffer  315  to the thin-client terminal system  340  so that the thin-client terminal system  340  can create a copy in its screen buffer  360 . 
     The audio system within thin-client terminal system  340  operates in a similar manner to the video system. The audio system consists of a sound generator  371  coupled to an audio connector  372  for creating an audio signal for an output device such as monitor  367 . The sound generator  371  is supplied with audio information thin-client control system  350  using audio information sent as output  321  by the thin-client server system  320  across bi-directional communications channel  330 . 
     From an input perspective, thin-client terminal system  340  allows for both alpha-numeric input and cursor control input from a terminal system user to be supplied to the thin-client computer system  320 . The alpha-numeric input is provided by a keyboard  383  coupled to a keyboard connector  382  that supplies signals to a keyboard control system  381 . Thin-client control system  350  encodes keyboard input from keyboard control system  381  and sends that keyboard input as input  325  to the thin-client server system  330 . Similarly, the thin-client control system  350  encodes cursor control input from cursor control system  384  and sends that cursor control input as input  325  to the thin-client server system  320 . The cursor control input is received through a mouse connector  385  from a computer mouse  385  or any other suitable cursor control device such as a trackball, trackpad, etc. 
     The thin-client terminal system  340  may include other input, output, or combined input/output systems in order to provide additional functionality to the user of the thin-client terminal system  340 . For example, the thin-client terminal system  340  illustrated in  FIG. 3A  includes input/output control system  374  coupled to input/output connector  375 . Input/output control system  374  may be a Universal Serial Bus (USB) controller and input/output connector  375  may be a USB connector in order to provide Universal Serial Bus (USB) capabilities to the user of thin-client terminal system  340 . 
     Thin-client server computer system  320  is equipped with thin-client server network software  397  for interacting with multiple thin-client systems. As illustrated in  FIG. 3A , the thin-client server network software  397  in thin-client server system  320  supports the thin-client terminal system  340  as well as any other thin-client terminal systems coupled to the same thin-client server system  320 . Each thin-client terminal system  340  will have its own associated screen buffer in the thin-client server system  320  such as thin-client terminal screen buffer  315 . 
     Unlike the thin-client terminal system  240  of  FIG. 2A , the thin-client terminal system  340  may communicate using digital information across bi-directional communications channel  330 , thereby allowing thin-client terminal system  340  to be placed any distance from thin-client server computer system  320 . In fact, as long as there is an appropriate digital communication channel  330 , a thin-client terminal system  340  could be used to interact with a server system  320  on the other side of the planet. Furthermore, standard network systems such as Ethernet may be used to implement the digital communication channel  330 . However, the sophistication of the electronic circuitry within thin-client terminal system  340  may render that system more expensive than thin-client terminal system  240 . Furthermore, thin-client terminal system  340  does not receive its operating power through the communication line such that each individual thin-client terminal system  340  requires its own power supply  453  which further increases the cost of thin-client terminal system  340 . 
     An Example Thin-Client Multiplier Device 
     To combine the features of the thin-client terminal system  340  along with the reduced cost of thin-client terminal system  240 , a thin-client multiplier device has been developed. The thin-client multiplier device allows a group of very inexpensive thin-client terminal systems to be located any distance from the server. The cost of such a system is much less than providing individual full thin-client terminal system  340  as illustrated in  FIGS. 3A and 3B  to each user. 
       FIG. 4A  illustrates a block diagram of an embodiment of a thin-client multiplier device  451  within a thin-client environment. The thin-client multiplier device  451  is coupled to thin-client server computer system  420  using a bi-directional digital communications channel  430  that may be a serial data connection (such as USB), a digital network connection (such as Ethernet), a wireless connection (such as 802.11), or any other suitable bi-directional digital communication means. The thin-client multiplier  451  may also be coupled to multiple thin-client terminal systems  440  (only one is shown) with a multi-conductor wire  432 . Multi-conductor wire  432  may be a Category 5 or Category 6 cable. In an example embodiment, input/output devices, such as a display device and one or more cursor control devices (e.g., keyboard, mouse) may directly connect to input/output ports in the thin-client multiplier device  451  as opposed to connecting to ports and connectors in the thin-client terminal system  440 . Direct connection of input/output devices to the thin-client multiplier device  451  may be desirable in cases where thin-client terminal devices are clustered or in close proximity. 
       FIG. 4B  illustrates a first conceptual diagram of a thin-client environment using the thin-client multiplier device  451  of  FIG. 4A . In the embodiment of  FIG. 4B , a thin-client server computer system  420  is coupled to a thin-client multiplier device  451  through digital network link  430 . Digital network link  430  may be a wired (e.g., Ethernet, USB) or wireless communication channel. The signal on the digital network link  430  may be carried on a digital computer network  428  (e.g., local area network, wide area network) to thin-client system  420  located remote from the thin-client multiplier device  451 . 
       FIG. 4C  illustrates a second conceptual diagram of a thin-client environment using the thin-client multiplier device  451  of  FIG. 4A . In the embodiment of  FIG. 4C , a thin-client server computer system  420  is coupled to two thin-client multiplier devices  451  through a USB line  430  and a USB hub  398 . Additional USB hubs  398  and thin-client multiplier devices  451  may be coupled to the USB line  430  as necessary to provide additional thin-client terminal systems  440  as needed until the data traffic on the USB line  430  becomes too heavy. The USB line  430  and the USB hub  398  may emulate a local area network or otherwise replace or substitute for a local area network. 
     The thin-client multiplier device  451  in  FIGS. 4B and 4C  is coupled to several local thin-client terminal systems  440 . Each of the individual thin-client terminal systems  440  is coupled to the thin-client multiplier device  451  using multi-conductor wire that may carry both information signals and electrical power such that thin-client terminal systems  440  do not need an external power supply. Specifically, all of the attached thin-client terminal systems may be powered from the power generated by the power supply  453  associated with the thin-client multiplier device  451 . 
     Referring back to  FIG. 4A , the thin-client multiplier device  451  receives all of the output information across digital bi-directional digital communications channel  430  for all the thin-client terminal systems coupled to that thin-client multiplier device  451 . Similarly, the thin-client multiplier device  451  transmits all user input received from the thin-client terminal systems  440  across the digital communications channel  430  to thin-client server computer system  420 . 
     Since the thin-client multiplier device  451  handles multiple thin-client terminal systems  440 , an addressing system is needed to identify which particular thin-client terminal system a particular unit of input or output information is associated with. In one embodiment, the thin-client multiplier device  451  obtains (or is assigned) a unique network address, such as an Internet Protocol (IP) address, for each individual thin-client terminal system  440  that the thin-client multiplier device  451  supports. In such an embodiment, the thin-client multiplier device  451  would appear to the thin-client server computer system  420  similar to several individual thin-client terminal systems  340  from the embodiment illustrated in  FIG. 3A . In this manner, the thin-client multiplier device  451  could be made backwards-compatible with the same thin-client server software used in the thin-client server system  320  illustrated in  FIG. 3A . Such a system would reduce product line complexity and simplify deployment. In an alternate embodiments, the thin-client multiplier device  451  may use a single IP address but different TCP/UDP port numbers or an proprietary addressing system to identify each of the individual thin-client terminal system  440  served by the thin-client multiplier device  451 . 
     Within the thin-client multiplier device  451 , a control system  450  receives all output from the thin-client server computer system  420  destined to any of the thin-client terminal systems coupled to thin-client multiplier  451 . Using one of the addressing systems mentioned above, the control system  450  determines which thin-client terminal system  440  output data is destined for and delivers the output data to output circuitry assigned with the addressed thin-client terminal system  440 . For example, if the thin-client server computer system  420  were to send audio data destined for thin-client terminal system  440  in  FIG. 4A , the control system  450  would pass that audio data to audio system  462  in a section of circuitry ( 460  to  465 ) dedicated to thin-client terminal system  440 . Audio system  462  then transmits an appropriate audio signal out to that thin-client terminal system  440 . The audio signal may be analog or digital depending on the specific implementation. 
     In the embodiment of  FIG. 4A , there are sections of circuitry for three different thin-client terminal systems: a first section of circuitry ( 460  to  465 ) for thin-client terminal system  440  and two additional sections of circuitry ( 470  to  475  and  490  to  495 ) for two additional thin-client terminal systems (not shown). Each of these sections of circuitry may be referred to as a terminal interface circuit. Each terminal interface circuit for a thin-client terminal system includes subsections for video output, audio output, keyboard &amp; mouse input, and power output. For illustration purposes only, three terminal interface circuits have been included in the thin-client multiplier  451  of the example embodiment of  FIG. 4A . However, it is contemplated that any number of terminal interface circuits may be included within the thin-client multiplier  451 . 
     Referring to the first terminal interface circuit ( 460  to  465 ) for thin-client terminal system  440 , the high-resolution video section consists of a frame decoder  461 , a video screen buffer  460 , and a video adapter  465 . The frame decoder  461  decodes digital video information received from the associated thin-client screen buffer  415  in the server  420  and places that digital video information into screen buffer  460  thus creating a representation of a video screen. Specifically, screen buffer  460  contains a copy of the bit-mapped display in thin-client screen buffer  415 . Video adapter  465  then reads the video display information out of screen buffer  460  and generates an analog video display signal to drive display system  447 . As set forth above, the audio system operates in a similar manner. Specifically, the audio system  462  is supplied with digital audio information from control system  450  and transmits an appropriate audio output signal to the associated thin-client terminal system  440 . The audio system  462  may decode and demodulated the audio data into an analog audio signal provided to the thin-client system. Alternatively, the audio system  462  may simply pass digital audio data to the associated thin-client terminal system  440  for decoding and demodulating by the audio circuitry  442  within the thin-client terminal system  440 . 
     From a user input perspective, an input interface  463  with each terminal interface circuit in thin-client multiplier device  451  receives both alpha-numeric input and cursor control device input from the associated thin-client terminal system  440 . The thin-client multiplier device  451  may support both Personal System/2-compatible devices (PS/2) as well as USB-compatible devices. The input interface  463  also may receive input from various slave devices, such as USB flash drives, portable hard drives, and music devices, that are connected to connectors or ports (not shown) in the associated thin-client terminal system  440 . In an example embodiment, the terminal interface circuit itself may include connectors or ports (not shown) by which slave devices may be connected. The input interface  463  passes this input data to control system  450  that encodes the input data with an address specifying that the input data is from the specific thin-client terminal system  440 . The encoded input data is then transmitted to the thin-client server system  420  across the bi-directional communication channel  430 . For example, the user input information received from a particular thin-client terminal system  440  may be sent from thin-client multiplier device  451  to the thin-client server system  420  using an IP address specifically associated with that thin-client terminal system  440 . 
     Finally, the subsection of circuitry within thin-client multiplier  451  associated with thin-client terminal system  440  may also include a power system that delivers power  464  across multi-conductor wire  432 , such as a Category 6 cable, to thin-client terminal system  440 . In this manner, the individual thin-client terminal systems  440  coupled to the thin-client multiplier device  451  do not need their own power supplies. This reduces the price of each thin-client terminal system  440 . The operating power for the thin-client multiplier device  451  and all thin-client terminal systems  440  coupled to that thin-client multiplier device  451  may be supplied by single power supply unit  453 . 
     Thus, the first terminal interface circuit ( 460  to  465 ) in thin-client multiplier  451  generates all the needed output signals for thin-client terminal system  440 . However, it is particularly noteworthy that the terminal interface circuit ( 460  to  465 ) in thin-client multiplier device  451  may generate the exact same signals on multi-conductor wire  432  that the server system  220  in the thin-client embodiment of  FIG. 2A  places on multi-conductor wire  230 . In this manner, the same thin-client terminal systems  240  from  FIG. 2A  can be used with the thin-client multiplier device  451  of  FIG. 4A . This can be verified by noting that the thin-client terminal system  240  of  FIG. 2A  includes the exact same internal components as the thin-client terminal system  440  of  FIG. 4A . 
     Due to this compatibility, the thin-client multiplier device  451  can be used as a backwards-compatible drop-in expansion device that allows a thin-client server system  320  from the thin-client embodiment of  FIG. 3A  to be expanded with multiple inexpensive thin-client terminal systems  240  from the embodiment of  FIG. 2A . The thin-client multiplier  451  may cost a little more than the single thin-client terminal system  340  since it contains multiple individual screen buffers ( 460 ,  470 , and  490 ), however much of the circuitry can be shared by the terminal interface circuits. For example, the same power supply circuitry can be used to generate all of the power output signals.  464 ,  474 , and  494 . Furthermore, a single fast processor can serve as the control system  450  and as all of the frame decoders ( 461 ,  471 , and  491 ). Thus, the thin-client multiplier device  451  should only cost marginally more than the cost of a single thin-client terminal system  340  from the embodiment of  FIG. 3A . And since the cost of the simple thin-client terminal system  240  of  FIG. 2A  is much lower than the cost of the thin-client terminal system  340  of  FIG. 3A , the usage of a thin-client multiplier device  451  and a set of thin-client terminal systems from  FIG. 2A  may be significantly less than the same number of thin-client terminal systems from  FIG. 3A . 
       FIG. 4D  illustrates an alternate embodiment of the thin-client multiplier  451  from  FIG. 4A . In the embodiment of  FIG. 4D , the functionality from the thin-client terminal system  440  has been integrated into the thin-client multiplier  451  for two of the terminal interface circuits. In this manner, keyboards  483 , mice  486 , and displays  447  (collectively, “input/output devices”) may be coupled directly to the thin-client multiplier  451  to create terminal workstations without requiring additional thin-client terminal boxes  440 . This further reduces the cost for implementing a thin-client terminal system. Note that the functionality from the thin-client terminal systems  440  may be integrated into the thin-client multiplier  451  for any number of terminal interface circuits. 
     The preceding technical disclosure is intended to be illustrative, and not restrictive. For example, the above-described embodiments (or one or more aspects thereof) may be used in combination with each other. Other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the claims should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
     The Abstract is provided to comply with 37 C.F.R. §1.72(b), which requires that it allow the reader to quickly ascertain the nature of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.