Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
287 words
In a video display terminal having a multi-page video memory wherein data are stored in addressable locations in a plurality of immediately adjacent pages in said video memory for presentation on a video display, a paging and scrolling system for displacing the displayed contents of entire selected pages in a first mode of operation and for displacing line-by-line the displayed contents of a selected one of said adjacent pages in said video memory in a second mode of operation, said system comprising: processing means responsive to user-initiated inputs for generating a mode control signal and a first video memory page select address representing a selected one of said adjacent pages in the video memory; control means coupled to said processing means for generating a second video memory page select address and video RAM addresses respectively representing one of said immediately adjacent pages in the video memory and a plurality of sequentially ordered video memory addresses within said immediately adjacent pages; address latch means coupled to said control means and to said video memory for providing said video RAM addresses to said video memory and for outputting said second video page select address; and address pager means connecting said processing means and said address latch means to the video memory and responsive to said mode control signal for providing said first video memory page select address and said video RAM addresses to the video memory in said first mode of operation and for providing said second video memory page select address and said video RAM addresses to the video memory in said second mode of operation, wherein said selected one of said adjacent pages of the video memory wraps around itself in said second scrolling mode of operation.
Claim 2
Dependent Claim
287 words
In a video display terminal having a multi-page video memory wherein data are stored in addressable locations in a plurality of immediately adjacent pages in said video memory for presentation on a video display, a paging and scrolling system for displacing the displayed contents of entire selected pages in a first mode of operation and for displacing line-by-line the displayed contents of a selected one of said adjacent pages in said video memory in a second mode of operation, said system comprising: processing means responsive to user-initiated inputs for generating a mode control signal and a first video memory page select address representing a selected one of said adjacent pages in the video memory; control means coupled to said processing means for generating a second video memory page select address and video RAM addresses respectively representing one of said immediately adjacent pages in the video memory and a plurality of sequentially ordered video memory addresses within said immediately adjacent pages; address latch means coupled to said control means and to said video memory for providing said video RAM addresses to said video memory and for outputting said second video page select address; and address pager means connecting said processing means and said address latch means to the video memory and responsive to said mode control signal for providing said first video memory page select address and said video RAM addresses to the video memory in said first mode of operation and for providing said second video memory page select address and said video RAM addresses to the video memory in said second mode of operation, wherein said selected one of said adjacent pages of the video memory wraps around itself in said second scrolling mode of operation.
Claim 3
Dependent Claim
21 words
The system of claim 1 further comprising user-responsive input means coupled to said processing means for providing user input commands thereto.
Claim 4
Dependent Claim
13 words
The system of claim 2 wherein said user-responsive input means comprises a keyboard.
Claim 5
Dependent Claim
36 words
The system of claim 1 further comprising a plurality of system address lines for connecting said processing means and said address pager means for addressing said selected one of said adjacent pages in the video memory.
Claim 6
Dependent Claim
33 words
The system of claim 1 further comprising a plurality of display address lines connecting said address latch means to said address pager means for addressing a plurality of pages in the video memory.
Claim 7
Dependent Claim
39 words
The system of claim 1 further comprising an address bus connecting said address pager means to the video memory, said address bus including a plurality of memory address lines for addressing a plurality of pages in the video memory.
Claim 8
Dependent Claim
25 words
The system of claim 1 wherein the video display is a raster-scanned cathode ray tube and said control means comprises a cathode ray tube controller.
Claim 9
Dependent Claim
14 words
The system of claim 1 wherein said address pager means comprises a multiplexer circuit.