Screen manager for data processing system

Claim 2

In a data processing system comprising a CPU (22)controlled through an operating system (38) and application tasks (46) so as to be able to process multiple application tasks (46) together, a data storage memory, and a video display (32), having a physical display screen (50), responsive to the application tasks (46), the operating system (38) having a screen manager (60) comprising: means responsive to a plurality of application tasks(46) to designate a plurality of virtual screens (76), all virtual screens corresponding to the same, single portion of the physical display screen (32); means responsive to an input to the data processing system to select one of the virtual screens (76) for display at said single portion of the physical display screen (32) under control of an application task (46); and means for controlling display (32), at a second portion of the physical display screen, of identifiers corresponding to the designated virtual screens (76).

Claim 3

A data processing system as claimed in Claim 1 wherein the virtual screens (76) are designated in descriptor data blocks (72) stored by the screen manager (60) and the descriptor blocks (72) point to stored data processed through the application task (46) which is to be displayed, and wherein the screen manager (60) further comprises means for modifying the descriptor blocks (72) in response to application tasks (46) regardless of whether a virtual screen (76) associated with a particular descriptor block (72) is at that time being displayed.

Claim 4

A data processing system as claimed in Claim 1 wherein the identifiers displayed in the second portion of the physical display screen indicate the status of the background tasks.

Claim 5

In a data processing system comprising a CPU (22) controlled through an operating system (38) and an application task (46) so a to be able to process the application task (46), a data storage memory (48), and a video display (32), having a physical display screen (50), responsive to the application task (46), the operating system (38) having a screen manager (60) comprising: means responsive to an application task (46) to designate as a plurality of viewports (80) distinct portions of the physical display screen (32) and to designate corresponding distinct sections of data, stored in the data storage memory (48), to be displayed in the respective viewports (80), each viewport designated after a first viewport being formed as a subdivision of a larger viewport; means for controlling display of each designated section of data in its corresponding viewport (80) portion of the physical display screen (32); means responsive to the application task (46) for changing the designated distinct viewport (80) portions of the physical display screen (32) and for independently, for each viewport (80), changing the designated distinct sections of stored data corresponding to each viewport (80) and to thus change the display of data; and means for updating the display to include changes in the stored data made by the application task.

Claim 6

In a data processing system comprising a CPU (22) controlled through an operating system (38) and an application task (46) so a to be able to process the application task (46), a data storage memory (48), and a video display (32), having a physical display screen (50), responsive to the application task (46), the operating system (38) having a screen manager (60) comprising: means responsive to an application task (46) to designate as a plurality of viewports (80) distinct portions of the physical display screen (32) and to designate corresponding distinct sections of data, stored in the data storage memory (48), to be displayed in the respective viewports (80), each viewport designated after a first viewport being formed as a subdivision of a larger viewport; means for controlling display of each designated section of data in its corresponding viewport (80) portion of the physical display screen (32); means responsive to the application task (46) for changing the designated distinct viewport (80) portions of the physical display screen (32) and for independently, for each viewport (80), changing the designated distinct sections of stored data corresponding to each viewport (80) and to thus change the display of data; and means for updating the display to include changes in the stored data made by the application task.

Claim 7

A data processing system as claimed in Claim 4 wherein each of the viewports (80) and the corresponding sections of data are designated in descriptor data blocks (72) by the screen manager (60).

Claim 8

A data processing system as claimed in Claim 5 wherein each descriptor block (72) includes the size of a viewport (80) and its logical location relative to data in the data storage memory (48).

Claim 9

A data processing system as claimed in Claim 6 wherein the screen manager (60) further comprises means for changing the logical position specified in the viewport descriptor data block (72) in response to a cursor position indicated by the application task (46).

Claim 10

A data processing system as claimed in Claim 5 wherein the screen manager (60) comprises means for further subdividing viewports into smaller viewports.

Claim 11

A data processing system as claimed in Claim 8 wherein the screen manager (60) comprises means for merging viewports to remove a subdivision of a viewport.

Claim 12

A data processing system as claimed in Claim 7 wherein the application task software includes means for designating both text and other data to be superimposed in the area.