Simultaneous display of interleaved windowed video information from multiple asynchronous computers on a single video monitor

• US 5,036,315 A
• Filed: 09/06/1988
• Issued: 07/30/1991
• Est. Priority Date: 09/06/1988
• Status: Expired due to Fees

• Current Assignee: SpectraGraphics Inc
• Original Assignee: SpectraGraphics Inc
• Inventors: Gurley, James
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): HJERPE, RICHARD A
• Application Number:
  US07/241,031
• Time in Patent Office: 1,057 Days
• Field of Search: 340/721, 340/723, 364/518, 364/521
• US Class Current: 715/733
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2340/125 wherein one of the images is motion video
• CPC Class Codes: G09G 5/008 Clock recovery
• CPC Class Codes: G09G 5/12 Synchronisation between the display unit and other units, e.g. other display units, video-disc players
• CPC Class Codes: G09G 5/14 Display of multiple viewports
• CPC Class Codes: G09G 5/36 characterised by the display of a graphic pattern, e.g. using an all-points-addressable [APA] memory
• CPC Class Codes: G09G 5/39 Control of the bit-mapped memory

Abstract

A first computer workstation running windowed display system and applications programs produces a first video signal of a composite, windowed, display plus a first data signal indicating the dedications, positions, and sizes of all windows. A second computer asynchronously digitally communicates a second display signal to a communications controller and then to a display controller. The display controller also receives the first data signal plus the sync pulse of the first video signal. It produces, from the second display signal, a second video display signal that (i) is synchronized with the first video signal and (ii) contains display information positioned and scaled to be within a window dedicated to the second computer. It produces a switch control signal indicating the portions of each raster scan of the synchronized video signals that are inside and outside the dedicated window. The switch control signal gates in a video switch either the first or the second video signal to a video monitor. The video monitor displays windows showing information from the first computer plus a dedicated window showing information from the second computer.

Claims

1. A system for simultaneously displaying information in a multiplicity of display windows upon a single monitor resultant from the simultaneous asynchronous display signals arising at a plurality of computers, the system comprising:

a first computer running a windowed display program for producing a first video frequency analog signal bearing information suitable for display, and a signal indicating the location and size of a window reserved for display use by the second computer;

a second computer for producing a signal bearing information suitable for display;

a communication and display controller receiving (i) the second computer'"'"'s display signal, (ii) so much of the first computer'"'"'s first video frequency analog signal as permits recognition of its video synchronization, and (iii) the first computer'"'"'s signal indicating the location of the reserved window,

for outputting the second computer'"'"'s display signal as a second video frequency analog signal synchronized to the first video frequency analog signal,

for scaling and locating the informational content of the second video frequency analog signal to be within the reserved window of a display, and

for producing a switch control signal indicating periods when each raster of the synchronized first and second video frequency analog signals is inside the reserved window;

a video switch, receiving the synchronized first and second video frequency analog signals and the switch control signal, for gating the second video frequency analog signal when the video raster is inside the reserved window area and for gating the first video frequency analog signal at other times; and

a display, receiving the gated synchronized first and second video frequency analog signals, for displaying a reserved window inside of which appears information from the second computer and outside of which appears information from the first computer.

2. An apparatus connectable to and usable with

a first computer running a windowed software program for producing a first display signal,

a second computer running a software program for producing a second display signal,

at least one of the first display signal and the second display signal being a video frequency analog signal, and

a video monitor producing a display in response to a received video frequency analog signal, to the end of simultaneously displaying interleaved windowed video information from both the first computer and the second computer on the video monitor, the apparatus comprising:

first computer operational control means within the first computer for reserving a window within the running windowed software program and for producing a data signal containing information on the reserved window'"'"'s position and size;

converting/synchronizing/windowing means receiving the first and the second display signals and the data signal

for converting the first and the second display signals to video frequency analog signals as each requires and for synchronizing both the first and the second video frequency analog display signals;

for scaling and locating the informational content of the second video frequency analog display signal so that it will appear within the area of the reserved window, and

for producing a switch signal upon each raster of the synchronized first and second video frequency analog display signals that indicates the periods that the video raster is outside and inside the area of the reserved window;

video switch means, receiving the first and the second video frequency analog display signals and the switch signal, for gating the first video frequency analog display signal to the video monitor during periods that the video raster is outside the area of the reserved window and for gating the second video frequency analog display signal to the video monitor upon other times.

3. A combination of, and improvement upon, selected elements from a first computer graphics workstation having

a 1) first computer for running applications software in a windowing environment for causing the outputting of a a) first video frequency analog display signal,

a 2) first monitor receiving the a) first video frequency analog display signal for producing windowed video displays, and from a second computer graphics and communications workstation having

a (3) second computer running applications software for causing the outputting of a b) second display signal,

a (4) communication and display controller receiving the b) second display signal and outputting responsively thereto a c) second video frequency analog display signal, and

a (5) second monitor receiving the c) second video frequency analog display signal for producing a video display,

wherein the communications and display controller and the second monitor jointly emulate a display terminal,

the selective combination and improvements directed to employing computers 1) and 3), plus a modification of communications and display controller 4), plus a one of monitors 2), 5) plus a new device in a new combination so as to place the video display of computer 3) in a window appearing upon the video display of selected monitor 2), 5) while the selected monitor is otherwise displaying windows in which appear displays from computer 1), the selective combination and improvement for simultaneously putting windowed displays from two computers on a single monitor comprising:

the

     1) first, system-window-managing computer running a windowing and a first applications software program for causing the outputting of the a) first video frequency analog display signal and also d) windows'"'"' locations data and e) identification of at least one window that is reserved to be filled with information from the

     3) second computer via the

     4) communications and display controller,

the

     3) second, host, computer running its applications software to cause the outputting of the b) second display signal;

a 4'"'"') modified communications and display controller running a microcode program

for receiving the b) second display signal, the d) windows'"'"' locations data, the e) reserved window'"'"'s identification, and at least so much of the a) first video frequency analog display signal as permits the video sync thereof to be recognized,

for outputting the b) second display signal as a c'"'"') second video frequency analog display signal that is synchronized with the a) first video frequency analog display signal and that bears informational contents both scaled and offset so as to be within the location of the reserved window when the a) first video frequency analog display signal is used by the selected monitor

     2),

     5) to produce a video display,

for producing an f) switch signal, in synchronization with both the c) second video frequency analog display signal and the a) first video frequency analog display signal, for indicating that each video frequency analog signal'"'"'s raster is either inside, or outside, the location of the reserved window,

a

     6) video switch, receiving the a) first video frequency analog display signal from the

     1) first computer and both the c'"'"') synchronized second video frequency analog display signal and the f) switch signal from the 4'"'"') modified communications and display controller, for gating the a) first video frequency analog display signal to the selected monitor

     2),

     5) while this a) first video frequency analog display signal is outside the location of the reserved window as a g) switched video frequency analog signal, else for gating the synchronized c'"'"') second video frequency analog display signal while this c'"'"') second video frequency analog display signal is within the location of the reserved window as the g) switched video frequency analog signal; and

a selected

     2),

     5) monitor receiving the g) switched video frequency analog signal and for producing a video display,

wherein information from the

     3) second computer is inside the reserved window while information from the

     1) first computer is outside the reserved window;

wherein two computers have simultaneously put windowed displays on a single monitor.

4. A method of simultaneously displaying windowed video information from two computers upon a single video monitor, comprising:

first producing, in a first system-windowing-managing computer accordance with its programmed operations

     1) a first video frequency analog display signal bearing windowed-video first information, and

     2) a dedicated-window information signal defining a dedicated display window where, when the first information is subsequently displayed as video, second information from a second computer may be presented;

second producing, in a second computer accordance with its programmed operations and asynchronously to the first producing, a

     3) second display signal bearing second information;

converting, in a display controller also receiving the

     1) first video frequency analog display signal and the

     2) dedicated-window information, the

     3) second display signal into a 3a) second video frequency analog display signal that has its second-information informational content scaled and located so that it will be within the dedicated window when the

     1) first video frequency analog display signal bearing the first information is subsequently displayed as windowed video, and that is synchronized with the

     1) first video frequency analog display signal;

generating, in the display controller in consideration of the synchronized

     1) first and 3a ) second video frequency analog display signals and the

     2) dedicatedwindow information, a switch control signal defining the portions of each raster scan of both the synchronized

     1) first and 3a) second video frequency analog display signals that are inside and outside of the area of the dedicated window;

switching, in a video switch receiving the switch control signal and the

     1) first and 3a) second video frequency analog display signals, between the synchronized

     1) first and 3a) second video frequency analog display signal so that the

     1) first video frequency analog display signal bearing the first information from the first computer is gated upon such times as the raster scan is outside the location of the dedicated window, and so that 3a) the second video frequency analog display signal bearing the second information is gated elsetimes;

displaying, in a video monitor receiving the gated

     1) first or 3a) second video frequency analog display signals, a display wherein second information from the second computer is within the dedicated display window and wherein first information from the first computer is elsewheres.

5. A method permitting a first and a second computer, each asynchronously running software generating an asynchronous display output signal, to collectively produce upon a common monitor a windowed display containing information from the first computer in some windows and information from the second computer within at least one window, the method comprising:

first producing, at a first system-window-managing computer in response to the running of a software program that reserves a display window within several display windows otherwise managed by this first computer, a video frequency analog display output first signal that contains information on the composite display of all display windows including the reserved display window, plus a output second signal that contains information on the locations and sizes of all display windows including the reserved display window;

second producing, at a second computer asynchronously with the first computer'"'"'s video frequency analog display output first signal, a display output third signal that contains information suitable for display in the reserved display window but uncorrelated in either time or position with information on the reserved display window that is contained within the first computer'"'"'s video frequency analog display output first signal;

receiving the second computer'"'"'s display output third signal into a buffer at a display controller, from which buffer the second computer'"'"'s display output third signal can subsequently be re-outputted asynchronously with its reception;

receiving into a circuit within the display controller information on the sync of the first computer'"'"'s video frequency analog display output first signal;

synchronizing, by action of the display controller circuit, a re-outputting of the second computer'"'"'s display output third signal as a video frequency analog display fourth signal that is in time synchronization with the first computer'"'"'s video frequency analog display output first signal;

generating, in the display controller circuit that receives the video frequency analog fourth signal and is accordingly informed thereby of the common synchronization of both video frequency analog first and fourth signals, and that also receives the output second signal from the first computer;

a switch control signal that indicates for each raster of the synchronized video frequency analog first and fourth signals that the video raster is or is not within the image area of reserved display window;

switching, in a video switch circuit receiving the first computer'"'"'s video frequency analog display output first signal plus receiving the synchronized video frequency analog display fourth signal derived from the second computer'"'"'s display output third signal via the display controller plus receiving the switch control from the display controller circuit, between the video frequency analog first and fourth signals to produce a composite video frequency analog display fifth signal that contains information from the first computer in all regions save the reserved display window and that contains information from the second computer in the reserved display window,

displaying on a monitor receiving the composite video frequency analog display fifth signal a windowed display that includes windows containing information from the first computer plus a reserved display window that contains information from the second computer.

6. A system for the simultaneous display of windowed interleaved video information upon a single video monitor from a plurality of sources comprising:

two computer means at least one of which is managing a windowed display for collectively producing two asynchronous display signals at least one of which is a video frequency analog signal plus, from at least that first one of the two computer means managing the windowed display, a data signal bearing information on the position and size of a window dedicated to the remaining one of the two computer

a buffering/converting and synchronizing;

positioning and scaling means receiving the two asynchronous display signals and the data signal,

for buffering either or both of the two display signals as required, and for converting a remaining one display signal to a video frequency analog signal as required, in order to produce two synchronized video frequency analog display signals,

for positioning and scaling the informational content of that video frequency analog display signal from or converted from the second one of the two computer means, as the case may be, so that is entirely positioned and sized within the dedicated window, and

for producing a switch control signal indicating the portion of each of the two synchronized video frequency analog display signals that is inside, and the portion that is outside, the dedicated window;

a video switch means receiving the synchronized video frequency analog display signals and the switch control signal for gating a one of the video frequency analog display signals when it is outside the dedicated window and the other one of the video frequency analog display signals when it is inside the dedicated window;

a display means receiving the gated video frequency analog display signals for producing a video display;

wherein information from the one of the two computer means managing the windowed display is displayed outside the dedicated window while information from the other one of the two computer means is displayed inside the dedicated window upon the video display.

7. An imaging system for displaying information from a first source outside a window, and information from a second source inside a window, in a windowed display, the system comprising:

a first source of a video frequency analog display signal;

a second source of a non-video frequency analog display signal;

wherein one of the first and the second sources is managing a windowed display and further produces a signal bearing information on a window dedicated to the other one of the first and second sources;

an imaging means receiving the first-source video display signal, the second-source non-video frequency analog display signal, and the signal bearing information on the dedicated window for producing a composite video frequency analog signal;

wherein an image from the second-source non-video frequency analog display signal is inside the dedicated window, and an image excepting an image of the dedicated window is outside the dedicated window, when the composite video frequency analog signal is displayed;

display means for displaying the composite video frequency analog signal.