CA2440825C - Method for display of terminal configuration menu - Google Patents

Abstract

There is a need for a terminal which is relatively inexpensive, reliable, ready to administer, secure and capable of displaying application program information within a multiuser Windows .TM. operating environment. Accordingly, a method for configuring a terminal having a display for communication with a host system and for updating terminal operating characteristics over a communications link from the host system is disclosed. In addition, a method is disclosed for implementing multiple personalities within a terminal and switching among such personalities The present inventi on may be applied to a video display terminal capable of operating with a graphical us er interface such as Windows .TM. and provides windowing functionality to permit use of popular applications programs resident on a server, without requiring more than application data to be transmitted from the server, and keyboard and mouse information to be transmitted from the terminal to the server.

Description

sJ

Field of the Invention The present invention relates generally to methods and apparatus for 30 displaying information on a terminal, and more particularly relates to methods and apparata for formatting and displaying, on a terminal, graphical user interfaces such as the Microsofit Windows operating environment and applications programs within such environments.

2 l 959f' Background of thE; Invention Graphical user interfaces such as the Microsoft Windows operating environment comprise the most popular operating environment for the world's best selling applications software. Such environments are typically preferred 5 because of ease of use, uniformity of use. interface, high quality display, as well as other reasons.
However, such user environments were designed for use with vvorkstations and microcomputers such as personal computers. Such workstations and microcomputers, while flexible, present difficulties with 10 security, reliability, ease of administration, ~snd value. While data terminals are known to offer the advantages of improved security and ease of administration relative to microcomputers, and usually at lower cost, terminals have generally been unable to provide compatibility with the most popular graphical user interfaces. Terminals operating in the X environment can provide Some graphical l 5 interface capabilities operating under Unix~, but typically are expensive, require extensive memory, and offer little compatibility with the most popular Windows environments.
Another option known in the prior art is diskless PCS. However, diskiess PCS offer severs! deficiencies. !n most instances, diskless PCS operating in a 20 client server erjvironment display application program information by downloading tine application from the server and executing the application focally. This requires the diskless PC fio have t-vhatever processing power is required for each application it attempts to exeo.ute. In today's environment, this can require eight or more megabytes of memory, a powerful processor, and so 25 on -- making a diskless PC expensive. !n addiiion, diskless PCS offer limited security and can require extensive administration.
The V'Jindows~' NT operating system provides a robust network client/server environment, while at the same time offering compatibility at the applications program lave! with the popular'Nindows"~ environment. However, 30 the NT operating system was written for PC clients, and not terminals. As a result, NT clients are generally required to be robust and, as a result, expensive, In addition, Windows NT was written for the client/server environment, and not the multiuser environment. The WinFrame operating system, recently offered by Citrix Systems, lnc., modifies the Windows NT operating system by extending it to operate in a multiuser environment, although the prior art application for WinFrame has been PCS clients as opposed to terminals.
There has therefore been a need for a terminal which is relatively inexpensive, reliable, easy to administer, secure and capable of displaying application program information within a multiuser Windows~ operating environment.
Summary of the Invention According to a first aspect of the present invention there i~ provided a method for configuring a terminal having a display for communication with a host system comprising: establishing at least one bit-mapped area within a portion of the display, establishing within the area at least one bit-mapped group comprising operating environment information of the terminal, and establishing at least one bit-mapped select within the group, each select having one or more choices associated therewith.
According to a second aspect of the present invention there is provided a method for configuring a terminal having a display for communication with a host system comprising: establishing at least one bit-mapped area within a portion of the display, establishing at least one bit-mapped group within the area, establishing at least one bit-mapped select within the group, each select having one or more choices associated therewith, and communicating with a memory information displayed in the bit-mapped portions of the display.
The present invention may be applied to a display terminal capable of communicating with an applications server running a multiuser operating system.
This provides secure access to Windows applications at the desktop. In an exemplary configuration, an application server is provided in the form of any suitable computer running the WinframeT"" operating system provided by Citrix Systems, Inc. The WinframeT"" operating system incorporates the Windows NT
operating system plus extensions implementing a display protocol known as ICA-as well as multi-user capabilities.
The terminal may include, in an exemplary embodiment, a hardware architecture based on the Intel X86 processor line. In addition, the terminal offers 3a only limited main memory, and is generally incapable of local execution of modern application programs such as word processing, graphics, database, or other popular programs, or even the Windows or DOS operating system itself. In this way the terminal is distinctly different from the prior art X terminals or diskless PCS, or other PCS configured in a client/server ._ ' ' 4 environment.
Importantly, the hardware architecture does not implement the conventional IBM PC/AT bus, and the firmware within the terminal implements neither standard PC/AT BIOS nor a standard PC-compatible disk operating system. The terminal firmware implements network access extensions compatible with the application server, again, for example, the ICA-3 extensions available from Citrix Systems. A high resolution graphical display is provided both for ease of use and may be either monochrome (including grayscale) or color, as well as input/output devices typical of the Windows environment such as mouse, keyboard, touchscreen and other I/O services:

In additional, the terminal includes a network interface capable of communicating with the application server across conventional RS232 lines, Ethernet connections, wireless, ISDN, fiber optic, AC power-line modems, cable or other connections. When connected to the application server, the terminal 1 5 displays the Windows NT or Windows 95 operating environment, including any application programs executing on the server and accessed by the user of the terminal. In the exemplary arrangement, the terminal appears to the user essentially the same as a much more expensive, less secure, harder to manage personal computer. As a result, during operation the terminal offers numerous features normally associated with a multiuser system, while at the same time offering many of the desirable features typical of a client/server environment.
One feature of the terminal is the availability of client-independent computing within a Windows environment. Thus, with a system according to the present invention, a user defines his operating environment and that environment follows him or her throughout the system. A user could therefore log onto one terminal, define an environment, and then log onto another terminal. That second terminal would automatically display the environment defined by that user at the first terminal.

The terminal may have a setup mode which permits the user to configure a variety of operating aspects of the terminal.
The present invention may implement a graphical user interface for configuration of a terminal and other locally managed tasks. In particular, the 5 graphical interface employs a plurality of windows and each window permits reconfiguration of one or more terminal characteristics or other local tasks.
Arranged in groups within each window are the selects which can be configured within that window. These selects, or choices, from which the user may select are displayed, or displayable through a pull-down or similar menu. Various data structures are associated with differing types of groups and selects.
To enable terminals to comply with commands sent.by servers such as those running WinFrame, a special purpose terminal operating system has been developed which either emulates or otherwise responds to the calls to a conventional PC operating system. The terminal operating system includes a boot block to initialize and, start the system, followed by a kernel which loads additional drivers and command software, including loading modified WinFrame client code.
Execution of the modified WinFrame client includes making a connection to an applications server.

The present invention may be better appreciated from the following Detailed Description given by way of non-limitative example with reference to the accompanying Figures, in which:
Brief Description of the DrawinrJs Figure 1 shows a generalised arrangement of an application server and a terminal.
Figure 2 shows in functional block diagram form the architecture of the logic of the terminal of Fig.1.

6a and for emulating one of the second and fourth sets of instructions, to provide to the associated host system responses compatible uvith the communications protocol associated with that host system, and switching means for identifying the host system to which the terminal is currently connected and selecting the appropriate one of the first and at least the second personalities for communications with the identified host system.
In accordance with a third aspect of the present invention there is provided a terminal for displaying, in the Microsoft Windows F~ operating environment, application pr ogram information provided by a host system running a Microsoft V1lindows~
operating systems comprising: interface means for receiving from the application server display information for an application program operating on the application server, processing means, not fully compatible with personal computer hiOS or disk operating systems and incapable of executing the application program locally, responsive to the interface means for either emulating or processing instructions supplied by programs executing on a rernotely located application server to provide to the host system responses compatible with those expected by the host system, display means responsive to the processing means for displaying the windowing information.
The above objects and summary of the present invention may be better appreciated from the following Detailed Description of the Invention tarcen in combination with the accompanying Figures.
2 0 Brief Description of the Drawincts Figure 7 shows a generalized arrangement of an application server and a terminal in accordance with the present invention.
Figure 2 shows in functional block diagram form the architecture of the logic of the present invention.

Figure 3 shows in block diagram form the architecture of the control ASIC
of Figure 2.
Figure 4 shows an overview of the software architecture of the terminal.
Figure 5 shows in simplified block diagram form the setup interface between the GUI Engine and the remainder of the system.
Figure 6 shows in flow chart form a top level view of the process by which the terminal connects to an application server.
Figure 7A shows a setup screen from the configuration software which implements the present invention.
Figures 7B1-7B3 show the data structures associated with the configuration software.
Detailed Description of the Invention Figure 1 shows a simplified system to ~ivhich the present invention may be applied. In particular, a single application server 10 communicates bidirectionally with one or a plurality of terminals 12 over a suitable network or other communications link 14. The network link may be an RS232 line, an AC power line modem, or an Ethernet connection such as twisted pair or coaxial cable, or other suitable link such as fiber optics. In a exemplary arrangement which has been determined to operate satisfactorily, the application server is running an operating systern such as Windows NT~ with appropriate extensions, such as those offered by Citrix as the Winframe OS. Tl~e Citrix remote windows protocol or extensions include the ICA 3.0 protocol as well as enhancements which provide true multiuser capability within the Windows NT
environment. For such a configuration, the application server may be, for example, a personal computer based on an Intel Pentium or ~48G prOCesJOr or other similar processors such as a DEC Alpha or a MIPS processor, or multiple processors, together with a suitable amount of RAM. In an uxan~plary configuration, the server may have sixteen megabytes of RAM for Winframe'"

OS, plus 1-8 megabytes of RAM per concurrent user, depending on the particular application being run by the user.
In appropriate configurations, the application server 10 may also communicate with other servers, including a NetWare file server 1 G, a Unix host 18, other personal computers 20, or an Internet gateway 22. Also, through other connections such as, a router or other communications server 24, the application server 10 may also communicate with remote terminals 26, or by other means to remote dial-up users 28.
Referring next to Figure 2, the hardware architecture of a terminal may be better appreciated. In particular, . _ a CPU 100, typically a microprocessor of the X86 family and in an exemplary embodiment an 80386CXSA or '486SXLC microprocessor, receives clock and reset signals from clock and reset logic 102. The CPU communicates with the remaining logic via an address bus 105, a data bus 106 and a CTRL bus 108.
Importantly, the buses 105, 106 and 108 are typically not compatible with the IBM PC/AT standard, nor any other personal computer standard, since the present invention is intended to avoid many, if not all, of the pitfalls associated with personal computers operating in a networked environment.
In particular, the address bus 105 extends from the CPU 100 to a control ASIC 110, as well as a flash memory array 112 and a VGA controller 1 14. The data bus 106 likewise communicates with the control ASIC 110, the VGA
controller 1 14, and a memory array 116. The CTRL bus 108 similarly provides control signals to the ASIC 110 and the VGA controller 1 14. Miscellaneous logic 1 18 provides CONFIG, IDCS and DIAGCS to the ASIC 110.
The ASIC 110 communicates with the memory array 1 16 via a DMA bus 120, and also communicates with the flash memory 1 12 via a PD bus 122. Tire PD bus 122 also provides communication between the ASIC 1 10 and the tlasl~
memory 112, a serial l/0 and parallel controller 124, a keyboard and mouse controller 126, as well as a LAN controller 1 28. In addition, the ASIC
provides an FCS signal to the flash memory 1 12, provides RAS, CAS and WE signals to ~' cy~~.~h the memory array 116, and provides COM1, COM2, and PPCS signals to the SIO
controller 124. Further, the ASIC 110 provides a KSCS signal to the keyboardlmouse controller 126, and provides an NETCS signal to the LAN
controller 128. Finally, the ASiC provides a speaker enable signal SPEN to a 5 speaker 130.
The CPU 100 also communicates with the S10 controller 124, the keyboardl mouse controller 126, and the L.AN controller 128 via a portion of the bus 105. In addition, the ASIC i 10 provides hardware interrupts INTA, INTB
and INTP to the SIO controller, provides hardware interrupts KBINT and MSIN'f 10 to tine KBIMS controller 12n, and provides hardware interrupt NINT to the LAN
controller 128.
The memory array 1 16 is typically comprised of DRAM memory, although other types of memory may be acceptable in some embodiments. However, unlike modern personal computers, the amount of DRAM in the array 116 1 5 required foe operation of the terminal typically will be within the range of 512 KB
to four megabytes. In an exemplary embodiment, only 23 memory address lines and a byte select line are used, which limits the memory space to 16 MB. In other embodiments different sizes of memory space may be preferred.
The Control ASIC 1 10, in an exemplary embodiment, contains f unctional 20 blocks for bus control, DRAM control (typical fast page mode with interleave), a system timer and speaker timer, and an I/0 controller. The Control ASIC may also be implemented as a gate array or oi;her highly integrated device, and is described in greater detail in connection with Figure 3.
In an operating example, it has been shown sufficient to size the flash 25 memory 1 12 on the order of 512KB; ho~rrever, in other applications a size of up to five megabytes or more may be preferred. While in a preferred embodiment the array 112 comprises flash memory, in some embodiments a substantial functionality of the present invention would remain even if the array was of EPROM and SRAM or other comparable memory devices.
30 The Si0 controller 124 communicates with COM1 , COM2 and printer (or 10 ;Jv9P
parallel) ports 132, l 34 and 136, r espectmeiy. T he Sl0/parallel controller may be a 16552 device, such as that available from Startech. The keyboard/mouse controller 126 similarly communicates with a keyboard 138 and mouse 140, while the LAN controller, which need not be peovided in all 5 embodiments, communicates with a t~AI~ interface 142. In one exemplary prototype, the keyboard/mouse controller 126 may be a standard keyboard controller, while the keyboard and arouse will both comply with the PS/2 standard, although in at least some embodiments the keyboard controller wilt be modified to be compatible with the four-wise keyboard interface described in U.S.
10 Patent No. 4,706,068. Pinaliy the LAN cor7troller may be any suitable network interface controller, and may comply with any accepted network standard, including 10BaseT, 108ase2, and others. The network interface may have 512168 memory or more for additional code storage.
The video and graphics controller 1 ? 4 has operatively associated 1 5 therewith a second memory array 144 for storing video and graphics information, which is supplied to a monitor 146 via an MP S 148. The video controller 1 14 may be, for example, a Cirrus 5429 device with interns! RAMDAC, and may have on the order of one megabyte of video merwory to provide high resolution graphics displays compatible with, as an example, at least the Video Graphics 20 Array standard. It will be apparent to those skilled in the art that the total memory requirements are distinctly fens than for a personal computer having similar capabilities to display Windows application programs. A sleep signal may be provided from the A SIC 1 10. Various methods for implementing a sleep signs! may be used. For example, in a monochrome version of the present 25 invention, a signs! is provided to the powor~ supply of the monitor, which disables the video signal and lowers the power required of the monitor power supply. In a color version, the sync signals are mani>.7ulated in accordance with the VESA
standard to cause the monitor to power down. !t will be apparent to those skilled in the art that, in the future, numerous of these functions, including the 30 CPU, may be incorporated into one or mare VLSI devices such as ASICs, gate arrays, or other devices.
In a special feature of the hardware, the terminal operating system stored in the flash memory 112 may be updated through a variety of methods, including communication through a suitable interface such as the parallel port 136, a serial port 132 or 134, or a network adapter s~~clms LAN interface 142. In an exemplary embodiment, the flash memory may be updated through communication with a host system when the terminal is placed in a predetermined state, such as by attaching a loopback plug, an appropriate key sequence or other suitable means. In such an arrangement, downloading to the terminal's memory system is enabled while still permitting communication with the host. The host then provides, via the communications link, updated operating characteristics either to the terminal's DRAM 1 16 or the flash memory 1 12 directly. Thereafter, the updated operating system information is stored in the flash memory 112 if necessary, and the terminal is returned a normal operating status in which downloading is disabled.
In normal conditions, the system of Figure 2 begins operation following a reset by beginning execution of the boot code contained in the flash memory array 112. The flash memory array 112 may be arranged in two banks, both of which are accessed at a predetermined address of the CPU memory space, for example C00000 - DFFFFF and E00000 - FFFFFF, while the remainder of the memory space is allocated to provide many of the normal PC functions as shown in Table 1, below. It will be apparent to those skilled in the art that, in an exemplary embodiment, the videolgraphics memory addresses are shifted eight megabytes beyond conventional PC memory addresses. In such an embodiment, the VGA chip may be used in "compatible" mode (i.e., linear addressing mode turned offl, so the VGA chip only responds to a frame buffer at AOOOOh - AFFFFh (in graphics mode) or BOOOOh - B7FFFh (for MGA mode) or B8000h - BBFFFh (for CGA mode), and that these addresses will be shifted to 8AOOOOh -8AFFFFh, and so on. The addresses have been shifted to permit hank 0 DRAM to be contiguous, while at the same time (and as discussed 1 2 ~ c) r~ y E:a heremafterl permitting functions sufficient emulation of normal to permn PC

display of Windows application program information.

5 Boot Block Flash File System Flash C00000 Network . BFFFFF

Card 880000 10 ArJditional Flash B7FFFF

Memory 800000 Video/Craphics AFFFFF

Controller 800000 DRAM

T~E3~.'B 'f 20 Bank 0 may be arranged into a 16K byte boot block at the upper address range, for example FFC000H - FFFFFFH, following two eight Kbyte parameter blocks, and further following a plurality of main blocks down to address F80000H (for a 512KByte allocation) or down to F00000H (if a one megabyte allocation is rnade~ or E00000H (if a two megabyte allocation is made!. The 25 main blocks of memory are typically organized as a file system. Bank 1 of the flash memory is typically allocated to a file system device, and may range from address DFFFFFH down to C00000H.
Referring next to Figure 3, the ASfC 1 10 r-r~ay be better appreciated. A
clock buffer 160 receives a CLK50 signal, and provides clock signals to RESET
30 SYNC logic l 62, DRAM control logic 16~., and timer control logic 1 6e. An (INTO buffer 168 receives iNTi', lNTA, INTB, MS1NT, KBINT and NINT signals as 1 3 1 ~~~.9F' set forth m I'abie 2. The RV T butfer provides a plurality of signals to interrupt Control logic 170, which receives a control signal from CPU Control input buffer 172 and a timer control signal from timer control logic 1 66 and generates an INTR output signal, which is provided to the CPU. The CPU Control input buffer .
5 1 7 2 also supplies a control signal to Cycle control logic 174, which in turn provides a contr of signal to DRAM control 1 G4. The DRAM control 1 64 also receives a refresh signal from timer control-logic 166; the timer control logic 166 also generates the speaker enable signal SPEN.
in the exemplary embodiment, the interrupt control logic 170 is not 8259 10 compatible; likewise, the system timer, or timer control logic 1 66, is not compatible, and operates at a higher frequency than an 8254-compatible device.
The result is that some of the higher frequency interrupts sent by the timer control logic are masked in the kernel, but others are passed through to approximate, ors average, the normal time between interrupts. The higher 15 frequency thus permits emulation of standard PC functionality even though the time between lower istandard) 'frequency emulated interrupts may not be uniform.
The ASIC 110 also includes a CPU Address input buffer 176, whick .~ receives BEO, BE'l and A1-A23 signals as described in Table 2 and provides an 20 output signal to a DRAM Memory Address Mux 178 as well as Mem/i0 Chip Select Control logic 180. The Mem/10 Chip Select Control logic 1 8O promdes a variety of output signals, including FLASHCSO (FCSO) and FLASHCS1 iFCS1 ) signals, and others as shown in Tab6e 2. Further, the ASIC 1 7 0 receives signals DO-15 from the data bus 108 and provides them to CPU Data input buffer 182.
25 The buffer 182 provides data to a Sdata Output Buffer & Latch 184, which supplies output signals BDO-15. The buffer 182 also provides data to Power control logic 186, which supplies SLEEP and PWRDWN signals.
T he signals BDO-1 5 can also provide data to 8data Input buffer 1 88, which in turn suppfies that data to CPU Data output buffer 190. The interrupt 30 control logic 170 also provides signals to the buffer 190. A configuration register 192 also provides a configuration signal (such as hardware configuration, for example how much flash and/or DRAM, or from the monitor power supply or from a plug-in card, for example, a network card) to the CPU
data output buffer, which can supply data on the bus 106 to the CPU.
Referring next to Figure 4, the key elements of the terminal operating system may be better understood. It will be appreciated from the foregoing that the hardware is not compatible with a standard AT-bus design. Instead, the present invention relies on firmware to provide the requisite BIOS services to the upper software Payers. In an exemplary embodiment, the firmware is designed to run i.n virtual 8086 mode, with AT-compatible hardware components such as the interrupt controllers and timers being emulated in software as closely as possible. In addition, while a standard keyboard controller is used in an exemplary embodiment, in the event a non-standard controller is used the interface to such a device would also be emulated. Signals such as I/0 from and to the ports of such hardware components are intercepted to facilitate the emulation. Also, under the control of an emulated A20 gate, the memory management features of the processor could be enabled to simulate the wraparound which occurs in normal hardware at one megabyte.
Continuing with reference to Figure 4, the terminal operating system begins execution with a boot block 300, followed by loading of a kernel 305.
The kernel 305 provides many of the intercepting and remapping functions of the present invention, as more particularly explained hereinafter. Upon completion of the kernel 305, the IO.SYS code 310 is loaded. Next the COMMAND.COM
code 315 is loaded, followed by executing commands provided by an AUTOEXEC.BAT fife. The AUTOEXEC.BAT file may include, for example, keyboard and mouse drivers although both such drivers may not be used in evrry instance, as well as a VGA XMS driver. It may also include other optional code, including starting a self-test sequence, which executes if appropriate conditions exist. In an exemplary embodiment, a loopback plug installed in o communications port causes the self-test sequence to execute.
The EXEC.COM code 325 is then loaded. At this point, depending on the implementation, either the system will enter setup mode, or user commands may cause either an entry of the setup mode or the loading of network connection 5 code. In a presently implemented embodiment, the system enters the setup mode to obtain current configuration data, and then continues with loading of the network connection code.
If the implementation permits the user to select, and if the setup mode is selected by the user, the EXEC.COM 325 branches to run the SETUP, or GUI
' 10 330. If the setup mode was not selected, the EXEC.COM 325 cooperates in the ..
loading and unloading of network drivers at 335 and begins the running of network connection code (again, ICA, thinwire, com, or other network) at 340.
In a presently preferred embodiment, the network connection code includes a substantially modified version of the Winframe for DOS client, the standard 15 version of which is available from Citrix Systems, Inc.
Now referring to Figure 5, the cooperation of the terminal operating system and the hardware architecture may be better appreciated. In particular, the lowest layer shown in Figure 5 is the Input/output system and hardware layer 400. The next higher layer is the Driver layer 402, while the top layer is the Application layer 404.
At power-on, the power-up and Init tests 406 in the hardware layer are performed as part of the boot block 300. The power-up and Init tests 406 execute partly out of the flash memory system 1 12 and partly out of RAM 1 16.
Once the power on self tests are completed, the terminal continues with the boot sequence described generally above in connection with Figure 4, including the remainder of the boot block 300, an AUTOEXEC sequence 408, and the COMMAND.COM sequence indicated at 315. Both the AUTOEXEC and COMMAND.COM files are maintained in the flash memory.
After the terminal's COMMAND.COM sequence executes, it causes the AUTOEXEC file to load. Ttie AUTOEXEC in turn causes the EXEC.COM 325 to Z ~'7 ~'~ ,' 1;7 ~ f a load. As noted above, the EXEC.COM sequence 325 can branch either to ct~c Setup Module 330 or the Network Connection module 340. At initial installation or any time thereafter that operating parameters of the terminal require verification or changing, the Setup Module 330 is run. The Setup Module 330 5 receives information from one or more setup data files 41 a and starts the engine 420. The GUI engine 420 in turn communicates with a keyboard driver 422, mouse driver 424, and the files and memory services driver 426 of the terminal operating system. In addition, the GUI engine 420 also communicates with the video Input/output system 428, which in turn provides data to the video l 0 controller 430, which may for example be based on a Cirrus 5428 graphics processor, to generate a video display during the setup sequence. The setup sequence will be described in greater detail in connection with Figure 5.
The keyboard driver 422 in turn communicates with the keyboard controller hardware 432, which may, for example, be a conventional PS12 15 keyboard Input/output system, a universe! serial bus (USB) interface, and in at least some embodiments may also include a four wire keyboard interface such as that described in the aforementioned U.S. Patent No. 4,706,068. Likewise, the mouse driver 424 is typically also communicating at appropriate times with I. a mouse Input/output system 434. Throughout such operations, the terminal 20 operating system's flash file and memory services portions 426 wil!
typically be executing out of flash and RAM.
As discussed in greater detail in connection with Figure 5, the setup process permits the user to specify the configuration information of the terminal, including such parameters as network interface and related configuration details, 25 language, colors, and other parameters. Once these parameters are specified, the data is stored in the connection data files 440.
At this point the user is ready to exit the terminal setup module 414, and return to the EXEC:COM. When allowed to continue, the EXEC.COM process 412 can be caused to branch to the netvdork connection module 416. The 30 network connection module 340 initiates by retrieving the data stored in the 1 7 . ~34i;-~P
connection data riles 440 and the command line of the connection rnoduie.
thereby communicating to the application :server how to talk to the rest of the driver and hardware Payers of the terminal. In particular, the network connection module communicates with the keyboard driver 422, the mouse driver 424, the 5 video input/output system 428, and the file and memory services portion 426 of the terminal operating system. in addition, the network connection module also connects a hardware serial interface 442, as we!! as, in some embodiments, a hardware network interface 444. The network drivers 444 execute out of RAM
1 16 in one exemplary embodiment, but may execute out of flash memory 1 1 2.
10 The serial interface 442 may be a conventional RS232 interface, but may also be another form of serial connection, such as the Universal Serial Bus, or USB.
Referring next to Figure 6, the operation of the GUI engine 420 shown in Figure 5 during setup module of the terminal 12 may be better appreciated. The GUI engine operates only during the setup mode, and provides a rudimentary 1 5 graphical user interface during the configuration operation.
As noted in connection with Figure 5, above, the operation of Figure 6 begins when the setup sequence is invoked during terminal boat up. The setup sequence rnay be invoked from a sequence of keystrokes or any other ~. convenient and suitable means. The setup sequence starts by calling setup 20 code 502, which in turn puns information from setup data files 418. The setup data files 418 identify the options available in the configuration of the term~al.
The setup code 502 communicates bidirectionally with a RAM structure 504, and also causes existing connection information from the connection data files 440 to be written into the RAM structure 504. The GUI engine 420 also 25 communicates bidirectionally with the RAIV1 structure to set up and display current information in an arrangement described hereinafter as areas, groups and selects. In addition, a hardware interface 506 provides video information to video controller 430 while responding to information received from the user via the mouse 260 and keyboard 250.
30 The setup code permits the user to cycle through a plurality of ~ ~~J~)1~
configuration menus for the operating characteristics of the terminal, such as the language displayed on the terminal, the network connection method, and so on.
Shown in Figure 7A is an illustration of a setup screen used in the configuration mode of the terminal. In a preferred emlJOdiment, the setup screens are displayed 5 graphically. As the user cycles through the configuration screens. the configuration data may be selectively updated by the user througfo use of tloc:
keyboard and mouse. The updated data is~ maintained in the RAM structure 504 before being written to the connection data files 436. However, in a presently preferred embodiment, certain of the data may be updated dynamically, while 10 other data is not updated until the setup sequence is completed. Upon completion of the setup sequence, including writing any remaining configuration data to the connection data files 436, the setup sequence exits and returns to the EXCC.COM 325 for initiation of the neimork ccnnection module 340 shown in Figure 5.
15 Continuing with reference to Figure 7A, the overall window in which the data appears will be referred to herein as an area 600. Within each area 600 are one or more groups 610, and each group 610 comprises one or more selects 620. Thus, in the example of Figure 7A, the "Communication" group includes the selects Serial Port, TCP/1P, SPX and IPX, each of which has associated 20 therewith a region 630 indicating that that select has been chosen, or selected.
Referring next to Figures 7B1 - 7133, the data structures associated with the configuration software are shown. In particular, a list of area painters is found in ARFA_LIST 700. The structures pointed to by the area list include boundaries, size, title and groups attached for af4 areas as defined by the SSTUP
25 process. As noted previously, each area appears as a window on the screen.
In addition, all areas which are currently being displayed are listed in DISP_AREA_LIST 702. In an exemplary embodiment, the first area listed is displayed as the bottom area, and the last area listed is the top area displayed.
In the exemplary embodiment, overlapping of windows is permitted although 30 ovGriapping is not necessarily required in all embodiments.

1 9 1 ~)5'3f~
At 704 is the data structure for GROUP_L1ST, which lists ail groups defined by the SETUP process in ail areas found in the AREA_L(ST 700. As previously noted, each area typically includes one or more groups. An optional data structure 706 for a STRING LIST may also be provided, and a FfLE LIST
5 708 is provided as a directory to bitmap images which may be used in multiple instances within the various areas, groups and selects.
The structure of the AREA LIST 700 can be seen at 710 to include a block for an area I,D 712, a painter to the next area 714, a painter to the previous area 71 fi, and a structure pointer 718. The structure pointer 71 8 10 associated with each area !D 712 points to an area structure 715 which includes the area ID 712 together with an ABS_X entry 720 and an ABS_Y entry 722 to give the location of that area relative to (in an exemplary embodiment) the top left carnet of the display. The area structure 714 also includes a ROWS entry 724 and a COLUMNS entry 726 that together specify the size of the area. A
15 FLAGS entry 728 specifies whether a border extends around the area. A
TITLE POSITION entry 730 and TfTLE_BAR entry 732 specifies the text of the title and its location within the title bar of the particular area, while a MAX STR LEN en=ry 734 specifies the maximum number of characters which ~. may be used for the title.
20 In addition, the area structure 714 also includes an entry 736 far the number of groups contained witt-iin the particular area. An AREA-MPTR entry 738 specifies tt-re mouse pointer hat spot within the area, while an entry DEF BUTTON 740 specifies which button within the area wits be the default.
The default button will be activated when the "enter" key is pressed. A
25 CAN BUTTON entry 742 specifies the cancel button, which wil! be activated when the "esc" key is pressed. Finally, a List of pointers, one for each group associated with the area, is specified at 744A-744N. Each group painter 744 points to an associated group structure block 746, discussed hereinafter. A
hot key list may also be defined far the area.
30 The structure of the DISP AREA LIST, shown at 748, is essentially 2G 1 ~35~ih identical to the structure of the AREA LIST 700, and includes blocks for area ID, next area, previous area, and structure pointer. As with the AREA_LiST 700, the DISP AREAyLIST 748 also points to the area structure 714. A similar structure for the GROUP f_1ST 704 is shown at J50, and includes a group ID 752, a next group pointer 754, a previous group pointer 756 and a group structure pointer 758. A similar structure for the optional STR1NG_LIST 706 may also Ue provided, and may include a string ID 760,. a next string pointer 7G2, a previous string pointer 7E~4; and a string structure pointer 766.
Referring again to the group structure pointer 758, it points to the group structure block 746 and includes the group ID 752, a PARENT~SELECT_ID entry 780, to identify the select which, when activated, will automatically pop up this group, a HOTSPOT COUNT entry 782 to identify the number of mouse hot spots within the group, and GSTART_X and GSTART_Y entries 784 and 786, respectively, to specify the relative location of tf~e group within the area.
In an exemplary embodiment, both the group and the select locations are specified relative to the top left corner of the area containing them; but other relationships may be defined that are also acceptable" such as specifying the location of a select relative to the location of its group. The most irrjportant element is to ensure that all features of an area m~iraain their position within the area if the area is moved.
The group structure block 746 also includes ROWS and COLUMNS entries 788 and 790, respectively, for specifying the size of th7e group, as wail a GFI.AGS entry 792 for specifying the harder of the group. In addition, a QUICK KEY POSITION entry 794 and a QUICK~KEY~STROKES entry 796 may also be specified for "hot" keystroke combinations associated with the group.
Further, and similar to the area structur e, entries for title position 798, group label 800 and MAXySTR_LEN 802 may be provided. In addition, a NUM OF SELECTS entry 804 is provided to identify the number of selects contained within a group. Next, an entry 806 for AID_ATTACFi is provided as a back reference to the area iD 712. 'with which the particular group is ~ a,r~cjE:>
associated. . he AiD ATTACH entry 806 is not reqwred in ail cases, but assvsts in improving performance in at least some instances. Lastly, a list of pointer entries 808A through 808N each point to a select structure associated with the particular group. As will be discussed hereinafter, a variety of select structures E may be associated with each group, but some elements are cowman among the various types. Thus, the first pointer- 808A points to a SELECT_COMMON
structure block 810. Referring again to the.area structure block 714, the default button entry 740 and cancel button entry 742 also point to the select common structure block 810.
10 The SELECT COMMON structure block 810 includes a select iD entry 812, an entry 814 giving back reference to the group ID, REL,X and REL_-Y
entries 816 and 818 together with ROWS and COLS entries 820 and 822 for specifying the location and size of the select, aUICK,KEY_POS and QUICK KEY CHR entries 824 and 826 for specifying the hot keystroke 15 combinations associated with the select, a M,AX-S'i'R LEN 828 and select string 830 for specifying the maximum size and title for the select, and an SFLAGS
entry 832 for specifying the characteristics of the select.
In addition, a SELECT TYPE entry 834- is also provided. As noted ~. previously, different types of selects are available, and reference is again made 20 to Figure 7A. The different types of selects which may be provided within a group depend on the type of data required at that step for configuring the terminal. In some instances, the choices involve only the pressing of a button (see buttons 640); in others, a select involves enabling or disabling a feature, as a check box isee 650 in Fig. 7A); in others, one of several choices must be 25 selected, as indicated in the "Communication" and "Serial Port" groups 660 and 670 of Figure 7A. In stilt others, an image may be selected, while in others specific text must be selected. In some, a fill-in entry is required f680 in Fig.
7A), while in others one of many fields must be filled in. Although these are the types of selects which have been implemented in an exemplary embodiment, the 30 list is not exhaustive and other selects can be readily implemented given the - 22 ' 959i' teachings herein.
For a "fill ira" select, cursor start and cursor end entries 836 and 838 are provided, together with a "first displayed" entry 840 for identifying from which character on the string should be displayed. In addition, a LABEL~REL_X entry 842 is provided as wet! as a LABEL REL Y entry 844 and a LABEL STR entry 846.
For a "one of many" select type, entries for NUM_OF_SEL_ROWS and NUM OF SEL COLS 848 and 850, respectively, are provided. Entries are also provided for the number of options 852 and default option 854, as well as a quick key pointer 856 and a flag pointer 858 to identify the number of option which are active. Finally, a select size 860 is also provided.
For an "image" type of select, only an entry for the file ID 708 and an image pointer 862 must be specified.
For a "fields°° type of select, a "child group" ID entry 864 is provided 1 5 together with a child group pointer, which points to a group structure of the type shown in group structure block 746. 'T'he child group will be popped up automatically when the parent select is activated, and one of a group of fields is selected.
For a "list of strings" select, entries are provided for number of options 868, the maximum length of the option titEe (or MAX OP_LEIV1 870, a horizontal display offset entry 872 and a vertical display offset entry 874, together with an X label position 878 and Y label position 880. Finally a label string 882 and a select string size entry 884 are provided.
Referring again to the AREA MPTR entry 738, the mouse pointer hot spot is specified by a structure which includes an area 1D entry 900, a group IDentry 902, and a select ID 904. In addition, an option select type 906 is provided to specify the type of select with which a particular hot spot is associated.
Further, back r eference entries 908 and 910 are provided for the group iD within the area, and the select ID within the group. Still further, four entries 912A-D
specify upper left X and Y positions as yv~:ll as lower right X and Y
positions far ~ n~C3J.~

the mouse hat spat, together with an entry 914 for mouse fl,sgs which cause tf~e mouse 'hot spot to be activated when the proper :menu is displayed. In addition to the hot spots described in the foregoing, additional hot spots are provided at the top and bottom of a list display, to allow scrolling, and in the title bar portion 5 of an area, to permit the area window to be moved.
In addition to the foregoing structures, a data structure is also provided for maintaining the currently selected entries from among the various choices.
The current data structure block is shown at 950, and includes an entry 952 for the number of areas currently defined by SETUP; an entry 954 for how r,~any 10 image files are defined; entries 956 and 958, respectively, for how many groups and selects have been defined, an entry 960 for allocating a predetermined maximum number of selects. In an exemplary embodiment, the maximum number of selects is allocated in blocks of ten.
Additional entries 962 and 964 are provided for the number of pixels per 1 5 column and row, .respectively, as welt as a font entry 966, an area focus entry 968, a group focus entry 970, and a string focus entry 972. Also, a mouse focus entry 974 is provided for specifying the hot spot. Further, OFOCUS and TFOCUS entries 976 and 978 may be provided for specifying select options and I~ select types with keyboard focus. Still further, (FOCUS and JFOCUS entries 20 and 982 are provided for the hotspot entries 908 and 910 from the mouse structure block described above. Finally, a menu entry 986 is specified for identifying the current menu focus, together with entries 988 and 990 for defining area borders and group borders, together with an OFLAGS entry for specifying mouse modes.
25 The information specifying the currerat state of the selects is specified in an ACTIVE SELECT structure 1000. Each structure includes a button entry 1002, an S'I'FLAGS, or select common flags, entry 1004, and an ACTIVE entry, which stores the current state of al! selects, from which that data may be r-nade available to the SETUP code.
30 In an exemplary embodiment, an event queue structure 1010 may also be 24 ~~ ':35''_)!~
supplied, for recording keyboard strokes and mouse movements in an event queue.
As noted previously, a key feature of the present invention is that the d terminal operating system of the present invention is not compatible with a 5 standard PCiAT B105 or DOS. However, the terminal operating system is required to support certain of these functions to maintain tfe ability to tlisploy application data in a multiuser environment, such as by interfacing to a Citrix client or other supported emulations. Attached as Tables 3A-3C is a list of the standard IO.SYS and SlOS.SYS functions which are supported by the present ~ 0 invention; it will be apparent to those skidled in the art that the list does not include numerous standard 1310S and DOS functions. Other functions are unsupported. 1n addition, some of the features which are listed are only partly supported in a presently preferred embodiment. Thus, Function 36h (Get Disk Free Space) is only partly supported due to the use of flash memory instead of t 5 a hard disk. Likewise, Function 33h [GetISet System Value] is supported in terms of function and flag, but the "Control-Break" function is not supported.
Similarly, Function 2Ah through 2Dh [GetlSe~t DatelTime functions) is only partially supported because no real time hardware is provided in the terminal of the present invention. The "Get Time" function is supported so that it may be 20 used to measure the duration of events, without reflecting absolute timQ.
!n addition, the flash file system of the present invention is, in the presently preferred arrangement:, partitioned into multiple single-directory drives.
f--lowever, unlike conventional disk files, the flash file system includes no clusters or sectors. Files within each drive or partition grow upwards from the 25 bottom of the partition, white directory entries grow downward from the top.
Files are stored contiguously, without fragmenting. Directory entries, which are sixteen bytes long in a preferred embodirr~ent, are generally similar to a DOS
directory entry; however, elements which would normally be reservf:d are defined to permit the file to execute out of flash; rather 'than DRAM. These 30 include the starting address of the file. Within the flash, as wet! as the remap 25 1 ')~.:~)!' segment of the file within the t~OS address specs.
File deletion, while also similar to deletion of conventional DOS files, also differs in some important details. When a file is deleted in the present invention, the first byte of the directory entry is changed to 0, as opposed to setting it to 5 ESh. This step is performed without erasing a flash block. Subsequent files will then be written to the next available space. However, if there is not enough available space for the subsequent files,-the flash block for the deleted file is erased and undeleted files are rewritten to the flash block where the deleted file had been maintained. As noted before, file fragmentation is not permitted in at 10 least same embodiments.
The flash file system supports conventions) DIR, TYPE and DEL
commands, supports a new "DEBUGMSG" command for generating a DEBUG
message, and also supports program execution 'through batch fifes. The file system also supports the AUTOEXEC.BAT file, as well as loading and executing 15 of .EXE and .COM files, and Int 21h and Int 27h. However, the file system does not support, in at feast some embodiments, the CONFIG.SYS file or .SYS device drivers. Likewise, the file system does not support batch file commands (except program executian], I/0 redirection, pipes, or interrupts 20h (Program Terminate], 22h (Terminate Address], 23h (Ctrl-Break Exit Address], 24.h (Critical 20 Error Handler Vector], 25h (Absolute Disk Read], 26h (Absolute Disk Write], and 2Fh (Multiplex Interrupt].
From the foregoing, it will be apparent that, while a selected group of the standard BIOS and DOS functions are emulated or otherwise supported by the terminal operating system of the present invention, a very significant number of 25 standard BIOS and DOS functions are not supported. in addition, even those BIOS and DOS functions which are supported are not executed by standard AT-campatible hardware. instead, the portion of the terminal operating system referred to in Figure 4 as the '°boot block" 300 and the "kernel" 305 establishes the ability to emulate these functions.
30 The service functions supported by the boot block 305 include: GET

26 1 ')~~5f' FLASH DRIVE SIZE, lrvhich interrogates the flash memory 438 for drive size;
READ FLASH DRIVE, far reading data from the flash memory 438; WRITE FLASH
DRIVE; GET FLASH DRIVE BLOCK SIZE, for interrogating the block size of the memory 438; ERASE FLASH DRIVE BLOCK, for erasing data from the memory 5 433; 1NARM REBOOT, used by the manufacturing test to loop through the power-on diagnostics repeatedly but not used in normal operation; GET.BOOT
BLOCK DATE; CLEAR KEYBOARD CONTROLLER I/O BIT, used to control components connected to the keyboard controller; and SE-f KEYBOARD
CONTROLLER IIO BIT.
10 The operation of the kernel 305 is shown in greater detail. In particular, the kernel includes three service functions. The first is an "ACTIVATE VIDEO
INT 10h" function, which enables the normal int lOh functions for video services. The interrupt int lOh is initially intercepted by the kernel 305 to suppress the display of text-mode messages from the various device drivers 15 while those drivers are loaded. After the drivers are loaded and the terminal enters graphics mode, the ACTIVATE VIDEO INT 10h function is called to restore normal int lOh operation. In addition, the kernel 305 includes a second function, "SET POWER DOWN TIME," which can set various power saving ~. functions (such as Energy Star compliance) and the delay timer for activating 20 such features. Finally, the kernel 305 includes a "PROCESS DOS INTERRUPTS"
function, which can be called from the boot block or other portions of the kernel 305 anytime necessary to process pending DOS interrupts which require real time processing in a DOS environment. The interrupts most often processed by this function are mouse and keyboard interrupts, although they may include 25 timer, serial, parallel and network interrupts. The interception by this function prevents, for example, mouse and keyboard interrupts from being disabled for an excessive period -- i.e.. long enough to be an annoyance to a user, for example a delay of about one second betvveen a movement of 4he mouse and a responsive movement of the cursor -- and to flush 'the keyboard controller's 30 output when it becomes necessary to . send a command to the keyboard 1, t~t~Cll) controller.
Since the hardware of the present invention does not comply with the PC; AT standard, and the fiirmware does not ccmply with either conventional PC; AT BIOS or DOS, but the overall s~rstem is intended to permit the user to 5 view and interact with a conventional Windows display, some conventional f~ardware interrupts and related calls must be managed by the present invention.
in a preferred embodiment, such interrupts. and calls are handled in the 'terminal firmware, either by emulating or modifying the appropriate response to t;oe incoming signal. Such responses will be treated in greater detail in connection 10 with the software kernel described hereinafter.
The kernel puts the processor in virtual $08fi mode and sets up various tables as necessary to intercept I10 to various ports. After an access to a selected port generates an exception, the instruction that generated the exception is disassembled so that the kernel can process it correctly to emulate 15 PC compatibility, thus simplifying the porting of various personalities.
Because an entire subroutine is executed for each intercepted I/O instruction, the l/0 instruction will not execute as fast, so intercepted I/0 is limited to as few ports as possible. In some instances, all or only a portion of an I/0 port is interrupted as necessary to provide AT compatibility. !t will be appreciated that, while the 20 primary embodiment described herein is intended to provide a Citrix Winframe personality, other personalities could also be implemented for use by the terminal of the present invention. In some instances, the terminal of the present invention may include multiple personalities in r-nemory, with the terminal connected to multiple hosts running different operating systems which expect 25 such differing personalities. The user or others may then be able to select from such personalities through a hot key or other sequence, with the kernel of the present invention then executing the aplpropriate personality out of memory and permitting communication to the appropriate 1-rost. --The i10 ports which are intercepted by the kernel to provide AT
30 compatibility are:

28 1 ,"~~:;i' 20h [The command port of an AT-compatible interrupt controlled -- iW 1y the "end of interrupt" command is emulated, which is issued at the end of every interrupt handler to allow more interrupts of the same or lesser priority to occur.
The kernel also emulates the normal operation of a PC-compatible interrupt 5 controller of blocking interrupts of equal or lesser priority until the "end of interrupt" command is received.
21h [The AT-compatible interrupt controller's mask register) -- Emulated.
40h-43h [Access to an AT-compatible 8254 system timer) -- The ports are not emulated, but are intercepted because some AT-based drivers write to these 10 ports. Since the interrupt mask register of an exemplary embodiment of the present invention is set at port 40h, unintercepted writes would interfere with the interrupt mask register of the present invention.
61h [A miscellaneous control port on an AT architecturel -- One speaker control bit is emulated to permit the speaker to be turned on and off.
15 AOh [The command port of an AT-compatible computer's second interrupt controller) -- As with port 20h, the "end of interrupt" command is emulated.
A1h [The mask register for the second interrupt controller isimiiar to port 21 h? I -- Emulated.
ZFBh through 2FFh [A standard address for an AT second serial part) --20 The ports are remapped to 5F0h through SFEh, which are the port addresses for the second serial port of an exemplary embodiment of the present invention.
The new port range [5F0 - 5FE1 includes even addresses only. In an exemplary embodiment, byte swapping has not been implemented, and thus only even bytes of the eight bit SI~ device can be accessed. However, byte swapping 25 may be implemewted if desired.
378h through 37Fh [A standard address for an AT parallel portl --Remapped to 6FOh through 6FEh, which are the port addresses for the parallel port of an exemplary embodiment of the pr esent invention.
3F8h through 3FFh [A standard address for an AT first serial port) --30 Remapped to 7FOh through 7FEh, which are the part addresses for the finest serial ,, ~~,~~~1, port of an exemplary e~nbociiment.
Having sully described a preferred embodiment of the invention and various alternatives, those skilled in the art wiil recognize, given the teachings herein, that numerous alternatives and equivalents exist which do not depart 5 from the invention. It is therefore intended that the invention not be limited by the foregoing description, but only by the appended claims.

Claims (5)

1. ~A method for configuring a terminal having a display for communication with a host system comprising:
establishing at least one bit-mapped area within a portion of the display establishing within the area at least one bit-mapped group comprising operating environment information of the terminal, and establishing at least one bit-mapped select within the group, each select having one or more choices associated therewith.

2. ~The method of claim 1 wherein the operating environment information of the terminal comprises network interface details of the terminal

3. ~The method of claim 1 wherein the operating environment information of the terminal comprises one or more languages to be displayed on the terminal.

4. ~The method of claim 1 wherein the operating environment information of the terminal comprises one or more colors to be displayed on the terminal.

5. ~A method for configuring a terminal having a display for communication with a host system comprising:
establishing at least one bit-mapped area within a portion of the display establishing at least one bit-mapped group within the area, establishing at least one bit-mapped select within the group, each select having one or more choices associated therewith, and communicating with a memory information displayed in the bit-mapped portions of the display