Data integrator for video display including windows

Claims

What is claimed:

1. A method of operating a computer-controlled video display terminal of the kind having a central processing unit, a memory, a video display screen and means for displaying selected data at selected coordinates on said screen, said central processing unit executing a control procedure stored in said memory for selecting said data and said coordinates; said memory including a set of registers storing codes for said data, and memory locations storing a set of control parameters defining (a) respective window regions on said display screen (b) a subset of said registers for display in each of said windows and (c) timing information for controlling how long the same data are displayed in each window; said method comprising the steps of said central processing unit executing said control procedure to select said data and coordinates by the steps of:

(1) readigg said control parameters defining said subset of said registers for display in each of said windows;

(2) selecting a particular register in said subset of said registers for each of said windows;

(3) reading said control parameters defining said respective window regions on said display screen for each of said windows;

(4) in response to said control parameters defining said respective window regions read in step (3) above, transferring at least some of the codes for data stored in the particular register selected in step (2) for each window to said means for displaying so that characters are selectively displayed at each fo said window regions corresponding to said codes transferred from the respective selected registers;

(5) reading said timing information; and

(6) using said timing information in combination with said control parameters defining said particular register selected in step (2) and said control parameters defining said respective window regions read in step (3), to selectively terminate the display of said data selectively displayed at each of said window regions;

wherein said steps are repetitively performed.

2. The method as claimed in claim 1, wherein said timing information includes the duration of the interval for which the same data are displayed in each window and the duration of an interval in which no data are displayed in each window.

3. The method as claimed in claim 2, wherein said display terminal further comprises a keyboard for entry of data by a user viewing said display screen, and wherein the duration of the interval from which the same data are displayed is adjusted by changing said timing information in response to data entered on said keyboard by said user.

4. The method as claimed in claim 1, wherein said display terminal further comprises a keyboard for entry of data by a user viewing said display screen, and wherein said step (4) of transferring includes successively transferring different portions of the codes in at least one register for certain ones of the windows so as to provide scrolling of the data displayed in at least one of the windows; said timing information includes the duration of the interval between said successive transfers of said different portions so as to control the rate of said scrolling; and said duration of the interval between said successive transfers is adjusted by changing said timing information in response to data entered on said keyboard by said user.

5. The method as claimed in claim 1, wherein said control parameters defining said window regions include parameters defining the size of each window region and its position on said display.

6. The method as claimed in claim 1, wherein said means for displaying includes means for displaying data in selected colors and said control parameters defining said window regions include parameters defining the foreground color of the data displayed in each window, and the background color of each window around the data displayed therein.

7. The method as claimed in claim 6, wherein said control parameters defining said window regions include a respective flag for selectively inhibiting the display of each window.

8. The method as claimed in claim 1, wherein said means for displaying includes means for displaying data using a selected pulsation and intensity and said control parameters defining said window regions include parameters for controlling the pulsation and intensity with which the data are displayed in each window.

9. The method as claimed in claim 1, wherein said memory further includes locations storing respective timing control parameters for each register which is read in step (5) and is used in step (6) along with the timing information (c) for each window to selectively terminate the display of said data.

10. The method as claimed in claim 1, wherein said control parameters (b) defining said set of registers for display in each of said windows includes an ordered list of registers and said step (2) of selecting a particular register selects the next register in said ordered list.

11. The method as claimed in claim 1, wherein said step (2) of selecting a particular register selects a new register at random from said subset of said registers.

12. The method as claimed in claim 1, wherein said step (2) of selecting a particular register selects a first one of said registers for display in a first one of said windows in response to the contents of a second one of said registers selected for display in a second one of said windows.

13. The method as claimed in claim 1, wherein said display terminal includes a keyboard for entry of data from a user viewing said screen, and said step (2) of selecting a particular register selects said register in response to data entered by said user from said keyboard.

14. The method as claimed in claim 13, wherein said data entered by said user is used as a key to select a particular register having contents corresponding to said key.

15. The method as claimed in claim 1, wherein said steps (1) to (6) are repetitively performed in response to a repetitive interrupt of said central processing unit.

16. The method as claimed in claim 1, wherein said display terminal includes a keyboard for entry of data from a user viewing said screen, and said steps (1) to (6) are repetitively performed when said user is waiting for data to be displayed on said video display in response to a service request entered from said keyboard.

17. A method of operating a computer-controlled video display terminal of the kind having a central processing unit, a memory, a video display screen and means for displaying lines of selected characters at selected locations on said screen, and means for entry of data from a user viewing said screen to said central processing unit, said central processing unit executing a control procedure stored in said memory for selecting said characters; said memory including a register storing codes for characters and at least one location storing a timing control parameter related to the size of said register storing codes for characters; said method comprising the steps of said central processing unit executing said control procedure to read said memory location to obtain said timing control parameter, successively transfer at least some of the codes from said buffer to said means for displaying so as to display lines of characters corresponding to said codes and so as to successively scroll said lines of characters at a predetermined rate, and to change the value of said timing control parameter in response to data entered by said user via said means for entry of data so that said user may variably select said scrolling rate while viewing said lines of characters on said display.

18. The method as claimed in claim 17 wherein said means for entry of data includes means for entering a first command for increasing the scrolling rate and means for entering a second command for decreasing the scrolling rate.

19. During the operation of a computer-controlled video display terminal by a user to interactively run a computer program, a method of displaying from time-to-time auxiliary messages to the user; said computer-controlled video display terminal including a video display screen, means for displaying selected characters at selected coordinates on said screen, means including a keyboard for entering commands from said user while viewing said display screen to interactively run said computer program, a central processing unit, and a memory; said memory including a set of registers storing codes for characters, and memory locations for storing a set of control parameters defining at least one window region of said display screen for the display of said auxiliary messages and timing information for controlling the intervals during which said auxiliary message are displayed in said window region; said method comprising the steps of said central processinguunit executing said control procedure to display from time-to-time said auxiliary messages in said window region by the steps of:

(1) selecting a particular one of said registers;

(2) reading said control parameters defining said window region on said display screen;

(3) in response to said control parameters defining said respective window region read in step (2) above, transferring at least some of the codes for characters stored in the register selected in step (1) to said means for displaying so that characters are selectively displayed at said window region corresponding to said codes transferred from the selected register;

(4) reading said timing information; and

(5) in response to said timing information, selectively terminating the display of said characters selectively displayed in the window region;

wherein said steps are repetitively performed to select different ones of the registers and thereby display different corresponding messages, and

wherein said central processing unit executes said control procedure to modify said timing information stored in said memory in response to commands received from said user via said means for entering to thereby modify the intervals during which said messages are displayed.

20. The method as claimed in claim 19, wherein register selection commands are received from said user via said means for entering, and wherein a particular register is selected in step (1) in response to said register selection commands.

21. The method as claimed in claim 19, wherein window position commands are received from said user via said means for entering for adjusting said control parameters defining said window region.

22. The method as claimed in claim 19, wherein said means for displaying includes means for displaying characters of selected colors, and said control parameters defining said window region include parameters defining the foreground color of the characters displayed in the window and the background color of the window around the characters displaye therein, and wherein said control procedure is executed to display a plurality of colors to said user and to receive from said user via said means for entering an indication of a selected foreground color and background color, and to use said indication for adjusting said parameters defining the foreground color and background color.

23. The method as claimed in claim 19, wherein said steps (1) to (5) are performed in response to a repetitive interrupt of said central processing unit.

24. The method as claimed in claim 19, wherein said steps (1) to (5) are repetitively performed when said user is waiting for said computer program being interactively run to respond to commands entered by said user from said keyboard.

25. During the operation of a computer-controlled video display terminal by a user to interactively run a computer program, a method of displaying from time-to-time auxiliary messages to the user; said computer-controlled video display terminal including a video display screen, means for displaying selected characters at selected coordinates on said screen, means including a keyboard for entering commands from said user while viewing said display screen to interactively run said computer program, a central processing unit, and a memory; said memory including a set of registers storing codes for characters, and memory locations for storing a set of control parameters defining at least one window region of said display screen for the display of said auxiliary messages and timing information for controlling the intervals during which said auxiliary message are displayed in said window region; said method comprising the steps of said central processing unit executing said control procedure to display from time-to-time said auxiliary messages in said window region by the steps of:

(1) selecting a particular one of said registers;

(2) reading said control parameters defining said window region on said display screen;

(3) in response to said control parameters defining said respective window region read in step (2) above, transferring at least some of the codes for characters stored in the register selected in step (1) to said means for displaying so that characters are selectively displayed at said window region corresponding to said codes transferred from the selected register;

(4) reading said timing information; and

(5) in response to said timing information, selectively terminating the display of said characters selectively displayed in the window region;

wherein said steps are repetitively performed to select different ones of the registers and thereby display different corresponding messages,

said central processing unit executes said control procedure to modify said timing information stored in said memory in response to commands received from said user via said means for entering to thereby modify the intervals during which said messages are displayed,

register selection commands are received from said user via said means for entering, and a particular register is selected in step (1) in response to said register selection commands,

window position commands are received from said user via said means for entering for adjusting said control parameters defining said window region, and

said means for displaying includes means for displaying characters of selected colors, and said control parameters defining said window region include parameters defining the foreground color of the characters displayed in the window and the background color of the window around the characters displayed therein, and wherein said control procedure is executable to display a plurality of colors to said user and to receive from said user via said means for entering an indication of a selected foreground color and background color, and to use said indication for adjusting said parameters defining the foreground color and background color.

26. The method as claimed in claim 25, wherein said steps (1) to (5) are performed in response to a repetitve interrupt of said central processing unit.

27. The method as claimed in claim 25, wherein said steps (1) to (5) are repetitively performed when said user is waiting for said computer program being interactively run to respond to commands entered by said user from said keyboard.

28. A computer-controlled video display terminal of the kind having a central processing unit, a memory, a video display screen and means for displaying selected characters at selected coordinates on said screen, said central processing unit providing means for executing a control procedure stored in said memory for selecting said characters and said coordinates; said memory inlcuding a set of registers storing codes for characters, and memory locations storing a set of control parameters defining (a) respective window regions on said display screen (b) a subset of said registers for display in each of said windows and (c) timing information for controlling how long the same characters are displayed in each window; and said control procedure including instructions for selecting said characters and coordinates by the steps of:

(1) reading said control parameters defining said subset of said registers for display in each of said windows;

(2) selecting a particular register in said subset of said registers for each of said windows;

(3) reading said control parameters defining said respective window regions on said display screen for each of said windows;

(4) in response to said control parameters defining said respective window regions read in step (3) above, transferring at least some of the codes for character stored in the particular register selected in step (2) for each window to said means for displaying so that characters are selectively displayed at each of said window regions corresponding to said codes transferred from the respective selected registers;

(5) reading said timing information;

(6) using said timing information in combination with said control parameters defining said particular register selected in step (2) and said control parameters defining said respective window regions read in step (3) to selectively terminate the display of said characters selectively displayed at each of said window regions; and

(7) repeating steps (1) to (6) above.

29. The apparatus as claimed in claim 28, wherein said timing information includes the duration of the interval for which the same characters are displayed in each window and the duration of an interval in which no characters are displayed in each window.

30. The apparatus as claimed in claim 29, wherein said display terminal further comprises a keyboard for entry of data by a user viewing said display screen, and wherein the control porcedure includes executable instructions for adjusting the duration of the interval from which the same characters are displayed by changing said timing information in response to data entered on said keyboard by said user.

31. The apparatus as claimed in claim 28, wherein said display terminal further comprises a keyboard for entry of data by a user viewing said display screen, and wherein said step (4) of transferring includes successively transferring different portions of the codes in at least one register for certain ones of the windows so as to pro ide scrolling of the characters displayed in at least one of the windows; said timing information includes the duration of the interval between said successive transfers of said different portions so as to control the rate of said scrolling; and said control procedure includes executable instructions for adjusting the duration of the interval between said successive transfers by changing said timing information in response to data entered on said keyboard by said user.

32. The apparatus as claimed in claim 28, wherein said control parameters defining said window regions include parameters defining the size of each window region and its position on said display.

33. The apparatus as claimed in claim 28, wherein said means for displaying includes means for displaying characters of selected colors and said control parameters defining said window regions include parameters defining the foreground color of the characters displayed in each window, and the background color of each window around the characters displayed therein.

34. The apparatus as claimed in claim 33, wherein said control parameters defining said window regions include a respective flag for selectively inhibiting the display of each window.

35. The apparatus as claimed in claim 28, wherein said means for displaying includes means for displaying characters of selected pulsation and intensity and said control parameters defining said window regions include parameters for controlling the pulsation and intensity of the characters displayed in each window.

36. The apparatus as claimed in claim 28, wherein said memory further includes locations storing respective timing control parameters for each register which is read in step (5) and is used in step (6) along with the timing information (c) for each window to selectively terminate the display of said characters.

37. The apparatus as claimed in claim 28, wherein said cottrol parameters (b) defining said set of registers for display in each of said windows includes an ordered list of registers and said step (2) of selecting a particular register selects the next register in said ordered list.

38. The apparatus as claimed in claim 28, wherein said step (2) of selecting a particular register selects a new register at random from said subset of said registers.

39. The apparatus as claimed in claim 28, wherein said step (2) of selecting a particular register selects a first one of said registers for display in a first one of said windows in response to the contents of a second one of said registers selected for display in a second one of said windows.

40. The apparatus as claimed in claim 28, wherein said display terminal includes a keyboard for entry of data from a user viewing said screen, and said step (2) of selecting a particular register selects said register in response to data entered by said user from said keyboard.

41. The apparatus as claimed in claim 40, wherein said data entered by said user is used as a key to select a particular register having contents corresponding to said key.

42. The apparatus as claimed in claim 28, wherein said steps (1) to (6) are repetitively performed in response to a repetitive interrupt of said central processing unit.

43. The apparatus as claimed in claim 28, wherein said display terminal includes a keyboard for entry of data from a user viewing said screen, and said steps (1) to (6) are repetitively performed when said user is waiting for data to be displayed on said video display in response to a service request entered from said keyboard.

44. A computer-controlled video display terminal of the kind having a central processing unit, a memory, a video display screen and means for displaying lines of selected characters at selected locations on said screen, means for entry of data from a user viewing said screen to said central processing unit, and a control procedure stored in said memory and executable by said central processing unit for selecting said characters; said memory including a register storing codes for characters and at least one location storing a timing control parameter related to the size of said register storing codes for characters; said control procedure including executable instructions for reading said memory location to obtain said timing control parameter, successively transferring at least some of the codes from said buffer to said means for displaying so as to display lines of characters corresponding to said codes and so as to successively scroll said lines of characters at a predetermined rate, and for changing the value of said timing control parameter in response to data entered by said user via said means for entry of data so that said user may variably select said scrolling rate while viewing said lines of characters on said display.

45. The apparatus as claimed in claim 44 wherein said means for entry of data includes means for entering a first command for increasing the scrolling rate and means for entering a second command for decreasing the scrolling rate.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention generally relates to computer terminals, and more specifically concerns computer-controlled video displays and systems for using these video displays for creativity, education, thought triggering, problem solving, new idea generation, speed reading and speed learning.

2. Description of the Related Art

The conventional method of using a computercontrolled video display for the presentation of alphanumeric data is by sequentially displaying the individual characters, lines of characters, or pages of characters.

Individual characters are sequentially presented to the user when the characters become available at a rate that is relativeyy slow compared to the response time of the human visual system. This response time is on the order of about 20 milliseconds. Therefore, it is customary for individual characters to be sequentially displayed as they are manually typed as input from a keyboard or as they are received from a serial data link operated at data rates of about 300 baud or less.

Characters are typically displayed on a line-by-line basis during a "scrolling" operation. After a full page of alphanumeric data has been received and displayed, for example on a character-by-character basis, the first line on the page containing the first presented data is nearly instantaneously changed to display the data previously displayed in the second line on the page, the second line is nearly instantaneously changed to display the data previously displayed in the third line on the page, and so on, so that the data displayed on the last line on the page is cleared to receive new characters or replaced with a new line of data. Therefore, during the scrolling operation all of the displayed data very quickly jumps up (or down) by one line. It is customary to inhibit scrolling until a control key is activated, in which case all of the data scrolls by one line each time the control key is activated. The scrolling operation is typically used in word processing programs during the display and editing of multi-page documents.

Data are typically displayed on a page-by-page basis during the display of a multi-page document or during the use of "menu driven" software. In menu driven software, a page or menu of selections is displayed to the user, and in response to a selection signal from the user, the next page of data is chosen from a group of predetermined pages of data, some of wiich may contain different menus for further selections.

It is known to divide the screen of a video display into separate regions for displaying respective groups of data. One part of a display, for example, has been used to show interactive dialog between the user and a data base management system, and the other part of the display has been used for showing records retrieved by the data base management system.

SUMMARY OF THE INVENTION

The primary object of the invention is to facilitate the process of maximum data integration by the mind of a human user.

A more specific object of the invention is to provide a convenient means for user control of the rate at which alphanumeric or graphic data are transferred from the video display to the mind of the human user, without substantial interference with the data transfer process.

Another object of the invention is to provide a convenient means for reinforcing the presentation of selected alphanumeric data or images to a human user and triggering pre-established thought patterns in response to the alphanumeric data or images.

Still another object of the invention is to provide a means for increasing the maximum rate at which alphanumeric data can be transferred from a video display to the mind of a human user without substantial loss of mental concentration or comprehension.

Moreover, another object of the invention is to provide a means for using normally "wasted" time during which the user of an interactive computer system waits for the system to respond to a service request.

Briefly, in accordance with important aspects of the present invention, a computer-controlled video display presents alphanumeric or graphic data to a human user in a fashion selected to provide user control of the data transfer rate and to increase mental concentration and comprehension. A set of video display regions or windows are defined having selected positions and areas for presenting data obtained from one or more registers or buffers. Associated with each display window is a set of stored parameters controlling the display of data in the window. The control parameters include, for example, parameters designating the size and location of each window, foreground and background colors and display intensity or pulsation, and the source of the data to be displayed. Other control parameters can be associated with the specific data source registers as well as specific display areas, such as the time interval over which the data are to be displayed, the time interval over which the window is to disappear after data are displayed, whether data are to be displayed on a repetitive, sequential or random basis, and selection of a scrolling rate. Preferably the control parameters are user-adjustable in a convenient fashion such a by entry from a mouse, by color palette selection, and by increasing or decreasing the timing control parameters.

To display data from selected registers during the execution of a related or unrelated computer program, it is advantageous to repetitively execute a separate control procedure for transferring data from the registers to the windows. Preferably this separate control procedure is executed on a timed interrupt basis and references an array of control parameters associated with the respective windows and an array of control parameters associated with the respective registers. The computer program may then exercise supervisory control by modification of the control parameters in the arrays. The control parameters, for example, include logical flags for enabling the display of data in the windows, and an interactive computer program may obtain exclusive use of the display by clearing the flags. By setting the flags when the user enters a service request to the interactive computer program, and clearing the flags when the interactive computer program has formulated a response to be displayed to the user, the time normally wasted during the execution of the interactive computer program can be used for displaying data in the windows. The display of subliminal messages in the windows, however, need not be inhibited when the interactive computer program is using the display.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:

FIG. 1 is a schematic diagram of a computercontrolled video display terminal using the present invention and having a number of windows for displaying the contents of selected memory registers;

FIG. 2 is a pictorial representation of the screen of the video display when used for selecting foreground colors;

FIG. 3 is a listing of control parameter arrays associated with the windows on the screen of the video display of FIG. 1;

FIG. 4 is a listing of the control parameter arrays associated with the memory registers shown in FIG. 1;

FIG. 5 is a diagram showing the transformation of window coordinates to screen coordinates of the video display of FIG. 1;

FIG. 6 is a flowchart of an executive control procedure for initially displaying the contents of selected registers in the windows on the video display of FIG. 1; and

FIG. 7 is a flowchart of a periodic interrupt routine which repetitively changes the alphanumeric characters displayed in the windows on the video display of FIG. 1.

The control procedure for the video display terminal of FIG. 1 is further shown in the computer code listings in Appendices II-VI.

While the invention is susceptible to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the drawings, and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular form disclosed, but, on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIG. 1, there is shown a schematic diagram of a computer-controlled video display terminal generally designated 10 employing the present invention. The terminal includes a video display 11 for displaying alphanumeric or graphic characters to a user (not shown), and a keyboard 12 for permitting the user to enter commands and data. The terminal 10 may include other means for permitting the user to enter data, such as a mouse 13. As is well known, the user may enter coordinate data with respect to the video display 11 by movement of the mouse 13 over a flat surface. Movement of the mouse 13 is reflected by movement of a cursor 14 until the cursor reaches a selected point on the display screen 15. The coordinates of the selected point are entered when the user activates a push button switch 16 on the mouse 13.

For controlling the operation of the video display 11 in response to commands or data entered from the keyboard 12 or the mouse 13, the video display terminal 11 includes a central processing unit 17 of the kind of which executes a control procedure comprising instructions fetched from addressable memory. As is conventional, the addressable memory includes read only memory (ROM) 18, and random access memory (RAM) 19. The ROM includes basic control steps for receiving data from the keyboard 12 and for transmitting instructions to the video display 11.

Depending on the particular application, the video display 11 is used as a remote terminal to another central processing unit (not shown) or on a stand-alone basis using the central processing unit 17 for executing a selected computer program. As shown in FIG. 1, the central processing unit 17 may execute a prestored computer program obtained from one of many data files 20. The data files, for example, are stored on a floppy disk. The ROM 18, for example, includes control steps executed in response to a command from the keyboard 12 in order to read a selected program from the data files 20, load the program into RAM 19, and to execute the program.

To permit the execution of programmed instructions at predetermined times, the computer-controlled video display terminal 10 preferably includes a clock 21, and the read only memory 18 includes a subroutine for obtaining the time indicated by the clock 21. The time is indicated, for example, by a number which is periodically incremented at intervals of 1 or more milliseconds. This number could be read directly by the central processing unit 17 from the clock 21, or it could be obtained from a random access memory location which is periodically incremented in response to a periodic interrupt of the central processing unit 17 by the clock 21. Although the use of a clock 21 for keeping track of timing intervals and for providing interrupts is not essential for practicing the present invention, it does simplify the programming of the video terminal 10.

For carrying out the present invention, the video display 11 is of the kind which has means for displaying selected alphanumeric or graphic characters at selected coordinates on the display screen 15 in response to instructions executed by the central processing unit 17. The graphic characters, for example, include blanks and dots, or more complex shapes formed as a matrix of dots.

A preferred kind of video display is a raster-scanned color cathode ray tube display. This kind of video display typically has a scanned memory for storing character codes, at least one memory location being provided for each row and column character postion on the display screen 15. The memory location stores a code number for specifying the character to be displayed, and may also include attributes associated with the display of that character. These attributes include, for example, the foreground and background color, intensity and pulsation of the displayed character. The scanned memory is addressed by raster scanning circuits which sequentially deflect the electron beam in the cathode ray tube along a path including the addressed character positions. Therefore, by addressing the character codes and attributes in synchronism with the scanning of electron beam, the information about each character to be displayed is obtained at the proper times to modulate the electron beam in the cathode ray tube.

As described above, the video display terminal 10 is recognized as having conventional components which may be used for a number of different purposes depending on the control procedures stored in the ROM 18 or read from the data files 20 into the RAM 19. The video display terminal 10, for example, could function as a master or slave terminal for a remote computer, or it could function as a stand-alone "personal" computer or be programmed for a specific application such as word processing or data-base management. The display terminal 10 is readily available in a variety of forms from numerous manufacturers in both the original equipment and the consumer markets.

In accordance with important aspects of the present invention, the computer-controlled video display terminal 10 presents alphanumeric or graphic data to a human user in a fashion selected to facilitate control of the data transfer rate and to increase mental concentration and comprehension. A set of video display regions or windows 22 are defined having selected positions and areas for presenting data obtained from one or more memory buffers or registers 23. Associated with each window 22 is a set of stored parameters for controlling the display of data in the window. As shown in FIG. 1, the stored parameters associated with each window are preferrably stored as arrays 24 in the random access memory 19. The control parameters include, for example, parameters defining the windows 22 on the display screen 15, a subset of the registers 23 for display in each of the respective windows, and timing information for controlling how long the same alphanumeric characters are to be displayed in each window. The control parameters defining the respective windows 22 on the display screen 15 include, for example, parameters designating the size and location of each window, the foreground color and the background color for each window, and the display intensity or pulsation of the characters displayed in each window.

Preferably during the display of data, the control information associated with each window is modified to some degree by control information associated with the selected register. Preferably the control information associated with the registers is stored in arrays 25 in the random access memory 15. Therefore, the control information for displaying the data in each window is obtained by reading the register control parameter arrays 25 for the selected register, reading the window control parameter arrays 24 for control information for the window, and combining the register control information with the window control information.

In accordance with another important aspect of the present invention, the central processing unit 17 executes a control procedure to display the alphanumeric or graphic characters in the windows 22 by reading the control parameters defining the subset of registers for display in each of the windows, selecting a particular register in the subset of the registers for each of the windows, reading the control parameters defining the respective windows, and in response to the control parameters defining the respective windows, transferring at least some of the codes for alphanumeric or graphic characters stored in the selected register for each window to the video display 11 so that corresponding characters are selectively displayed at each window. Also the central processing unit 17 reads the control parameters specifying timing information, and in response to the timing information, selectively terminates the display of the characters displayed at each windww. These steps are repetitively performed so that alphanumeric or graphic data from a number of different registers are displayed in each window.

In accordance with another aspect of the present invention, the control parameters are selected by the user either before or during the display of characters in the windows. Preferably the user selects the foreground and background colors before the windows are displayed. As shown in FIG. 2, this is conveniently done by displaying a palette of colors generally designated 30 on the screen 15.

In order to illustrate the various ways of controlling the display of characters from selected registers in user-defined windows, a specific example of window control parameter arrays and register control parameter arrays are shown in FIGS. 3 and 4. So that the user may interactively run any computer program from the terminal 10 while characters from the registers 23 are displayed in the windows 22 without interference with the running of the computer program, the transfer of the