EP0052755A2
Expired / Lapsed
EP
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Text-processing system generating multiple virtual displays on a single display screen
Assignee: International Business Machines Corp
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Filing: 1981-10-20
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Granted: —
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Expires: 2001-10-20
Abstract
Abstract System for generating multiple virtual displays on a single display screen by a display access method (DAM) program (80) running interrupt identified service programs. Each of the service programs (72, 82, 98 and 118) is provided with stack memory elements (74, 84, 100 and 120) for retaining data to run the program. Each of the service programs (72, 82, 98 and 118) is run by the DAM program (80) in accordance with priority interrupts with a higher priority interrupt having immediate access to the DAM program (80). A service program having a low priority interrupt that is being run will be stopped by the occurrence of a higher priority interrupt with the data and address information of the interrupted program retained in the stack memory elements (74, 84, 100 and 120). The service program of the higher priority interrupt is then run and when ended the DAM program (80) retrieves the data for the lower priority program to return to the point of interruption.
Inventors
- 👤 William Charles Cason
- 👤 Ward Arthur Kuecker
- 👤 Paul Ray Herrold
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 22:06
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/14; G06F3/153; G06F40/00; G06F40/10; G06F40/103; G06F40/106
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
145 words
System for generating multiple virtual displays on a single display screen, characterized in that it comprises : program storing means for storing service programs for each of the virtual displays of the single display screen, storage means for each of the service programs and having a data communication link to the program storing means, a storage buffer for each of the service programs and having a data communication link to the program storing means, display control block means for each of the service programs and having a data communication link to the program storing means, means for storing a display access method program having a communication link to said storage buffer and said display control block means for running each of the service programs, and means for buffering the outputs from the display access program to generate the virtual displays on a single screen display.
Claim 2
Dependent Claim
145 words
System for generating multiple virtual displays on a single display screen, characterized in that it comprises : program storing means for storing service programs for each of the virtual displays of the single display screen, storage means for each of the service programs and having a data communication link to the program storing means, a storage buffer for each of the service programs and having a data communication link to the program storing means, display control block means for each of the service programs and having a data communication link to the program storing means, means for storing a display access method program having a communication link to said storage buffer and said display control block means for running each of the service programs, and means for buffering the outputs from the display access program to generate the virtual displays on a single screen display.
Claim 3
Dependent Claim
30 words
System according to Claim 1 including interrupt arbitrator means responsive to a plurality of interrupts and selecting one of said service programs for running by said display access method program.
Claim 4
Dependent Claim
39 words
System according to Claim I or Claim 2 wherein said service programs include : (1) a diskette service program, (2) a printer service program, (3) a text application keyboard service program, and (4) a prompt manager keyboard service program.
Claim 5
Dependent Claim
33 words
System according to Claim 3 wherein said text application keyboard service program includes instructions for one section of a defined virtual display and a second independent defined section of the same virtual display.
Claim 6
Dependent Claim
149 words
Method of generating multiple virtual displays on a single display screen, characterized by the steps of : generating an interrupt from a plurality of interrupts on a priority basis, in response to one interrupt from the plurality of interrupts, calling and running an identified service program for a selected virtual display on the single display screen, interrupting the running of a service program having a lower interrupt priority than a subsequently generated higher priority interrupt, storing the data generated for the interrupted service program at the point of interruption by the higher priority interrupt, in response to the higher interrupt calling and running the service program identified by the higher priority interrupt for a selected virtual display on the single display screen, and buffering the output data from each of the service programs called by an interrupt to format a plurality of virtual images on a single display screen.
Claim 7
Dependent Claim
149 words
Method of generating multiple virtual displays on a single display screen, characterized by the steps of : generating an interrupt from a plurality of interrupts on a priority basis, in response to one interrupt from the plurality of interrupts, calling and running an identified service program for a selected virtual display on the single display screen, interrupting the running of a service program having a lower interrupt priority than a subsequently generated higher priority interrupt, storing the data generated for the interrupted service program at the point of interruption by the higher priority interrupt, in response to the higher interrupt calling and running the service program identified by the higher priority interrupt for a selected virtual display on the single display screen, and buffering the output data from each of the service programs called by an interrupt to format a plurality of virtual images on a single display screen.
Claim 8
Dependent Claim
36 words
Method according to Claim 5 wherein each service program retrieves from an associated stack memory element the number of display lines and the number of displayable positions for the virtual display defined by the service program.
Claim 9
Dependent Claim
24 words
Method Claim 5 or Claim 6 wherein the output data is buffered for each virtual display at a predefined address in a refresh buffer.
Claim 10
Dependent Claim
37 words
Method according to Claim 5, 6 or 7 including the step of running the called service program by a display access method program responsive concurrently to each of the plurality of service programs on an interrupt basis.
Claim 11
Dependent Claim
73 words
Method according to Claim 8 wherein the display access method program receives, for the running of each service program (1) the display start line of a virtual display, (2) the number of lines in the virtual display, (3) the address of the character column of the virtual display, (4) the number of character columns in a virtual display, (5) the address of a storage buffer, and (6) the length of the storage buffer.
References Cited (Backward Citations)
No citation records indexed.
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