Upshift control for video display

Claim 1

A system for displaying characters on a video display means of the type producing images of characters on a display surface by selectively writing on the display surface while repeatedly sweeping fields of a raster scanline pattern over the display surface, the characters being arranged in rows with new information first appearing in a row at one edge of the display and moving toward the opposite edge before disappearing, information being moved from one row to the previous location of the adjacent earlier displayed row during the period of an upshift cycle, said system including in combination memory means having a plurality of storage segments arranged in sequence, each segment being capable of storing data for a single row of characters, the data in any segment being erased automatically when new data is entered therein; recirculating means for causing each segment to be connected in recurring sequence to a memory input connection and to a memory output connection of said memory means at a memory recirculation rate; means for supplying new information data to the memory means at said input connection; memory upshift register means coupled between the output connection and the input connection of said memory means and being capable of storing data for a single row; memory upshift control means coupled to said memory upshift register means for reading out data from a different one of said storage segments during each memory recirculation cycle of an upshift cycle and storing the data in the memory upshift register means, and for removing the stored data from the memory upshift register means within the period of a memory recirculation cycle and storing the data in a different storage segment which is connected to the memory input connection earlier in a memory recirculation cycle than the storage segment from which the data was read out, the data for each row being relocated in the storage segments previously containing data for the adjacent earlier displayed row during the period of an upshift cycle; display register means coupled to the output connection of said memory means and being capable of storing data for a single row; memory output control means for reading out data for each row in turn from said storage segments of the memory means during each field of the raster scanline pattern and causing the data for each row in turn to be stored in said display register means; display register output control means for reading out the data for each row from said display register means at successively earlier times during each succeeding field of an upshift cycle; and video signal generating means coupled to the display register means for generating video signals for producing images of a row of characters on the display surface in response to the data for a row being read out of the display register means.

Claim 2

A system for displaying characters on a video display means of the type producing images of characters on a display surface by selectively writing on the display surface while repeatedly sweeping fields of a raster scanline pattern over the display surface, the characters being arranged in rows with new information first appearing in a row at one edge of the display and moving toward the opposite edge before disappearing, information being moved from one row to the previous location of the adjacent earlier displayed row during the period of an upshift cycle, said system including in combination memory means having a plurality of storage segments arranged in sequence, each segment being capable of storing data for a single row of characters, the data in any segment being erased automatically when new data is entered therein; recirculating means for causing each segment to be connected in recurring sequence to a memory input connection and to a memory output connection of said memory means at a memory recirculation rate; means for supplying new information data to the memory means at said input connection; memory upshift register means coupled between the output connection and the input connection of said memory means and being capable of storing data for a single row; memory upshift control means coupled to said memory upshift register means for reading out data from a different one of said storage segments during each memory recirculation cycle of an upshift cycle and storing the data in the memory upshift register means, and for removing the stored data from the memory upshift register means within the period of a memory recirculation cycle and storing the data in a different storage segment which is connected to the memory input connection earlier in a memory recirculation cycle than the storage segment from which the data was read out, the data for each row being relocated in the storage segments previously containing data for the adjacent earlier displayed row during the period of an upshift cycle; display register means coupled to the output connection of said memory means and being capable of storing data for a single row; memory output control means for reading out data for each row in turn from said storage segments of the memory means during each field of the raster scanline pattern and causing the data for each row in turn to be stored in said display register means; display register output control means for reading out the data for each row from said display register means at successively earlier times during each succeeding field of an upshift cycle; and video signal generating means coupled to the display register means for generating video signals for producing images of a row of characters on the display surface in response to the data for a row being read out of the display register means.

Claim 3

A system for displaying characters on a video display means of the type producing images on a display surface by selectively writing on the display surface while repeatedly sweeping fields of a raster scanline pattern over the display surface, the characters being arranged in rows disposed parallel to the direction of tracing individual scanlines and with new information first appearing in a row at one edge of the display and moving in a direction perpendicular to the direction of tracing individual scanlines toward the opposite edge before disappearing, information being moved from one row to the previous location of the adjacent earlier displayed row during the period of an upshift cycle, said system including in combination memory means having a plurality of storage segments arranged in sequence, each segment being capable of storing data for a single row of characters, the number of segments being at least twice the numbeR of rows of characters, the data for each row being stored in each of two storage segments, the data in any segment being erased automatically when new data is entered therein; recirculating means for causing each segment to be connected in recurring sequence to a memory input connection and to a memory output connection of said memory means at a memory recirculation rate which is an integral multiple of the field rate; memory upshift register means coupled between the output connection and the input connection of said memory means and being capable of storing data for a single row; memory upshift control means coupled to said memory upshift register means for reading out data from a different one of said storage segments during each memory recirculation cycle of an upshift cycle and storing the data in the memory upshift register means, and for removing the stored data from the memory upshift register means within the period of a memory recirculation cycle and storing the data in a different storage segment which is connected to the memory input connection earlier in a memory recirculation cycle than the storage segment from which the data was read out, the data for all the rows becoming stored in storage segments earlier in the recurring sequence during a relocation cycle having a period equal to an integral number of fields, the data for each row being relocated in the storage segments previously containing data for the adjacent earlier displayed row during the period of an upshift cycle, an upshift cycle having a period equal to an integral number of relocation cycles; incoming information means for supplying data for a new row of characters to the memory means at said input connection of the memory means to store the data in each of the two storage segments originally containing the most recent data at a time during each upshift cycle subsequent to relocating of the most recent data to earlier segments of the recurring sequence; display register means coupled to the output connection of said memory means and being capable of storing data for a single row; memory output control means for reading out data for each row in turn from said storage segments of the memory means during each field of the raster scanline pattern by reading out appropriate segments containing data for each row in turn earlier in the recurring sequence for each succeeding relocation cycle of an upshift cycle and causing the data for each row in turn to be stored in said display register means at an earlier time during the field for each succeeding relocation cycle of an upshift cycle; display register output control means for repeatedly reading out the data for each row from said display register means at the scanline rate for the number of scanlines of a row of characters, the data for each row being read out at successively earlier scanlines during each succeeding field of a relocation cycle; and video signal generating means coupled to the display register means for generating video signals for producing images of a row of characters on the display surface in response to the data for a row being read out of the display register means.

Claim 4

A system for displaying characters on a video display means of the type producing images on a display surface by selectively writing on the display surface while repeatedly sweeping fields of a raster scanline pattern over the display surface, the characters being arranged in rows disposed parallel to the direction of tracing individual scanlines and with new information first appearing in a row at one edge of the display and moving in a direction perpendicular to the direction of tracing individual scanlines toward the opposite edge before disappearing, information being moved from one row to the previous location of the adjacent earlier displayed row during the period of an upshift cycle, said system including in combination memory means having a plurality of storage segments arranged in sequence, each segment being capable of storing data for a single row of characters, the number of segments being at least twice the numbeR of rows of characters, the data for each row being stored in each of two storage segments, the data in any segment being erased automatically when new data is entered therein; recirculating means for causing each segment to be connected in recurring sequence to a memory input connection and to a memory output connection of said memory means at a memory recirculation rate which is an integral multiple of the field rate; memory upshift register means coupled between the output connection and the input connection of said memory means and being capable of storing data for a single row; memory upshift control means coupled to said memory upshift register means for reading out data from a different one of said storage segments during each memory recirculation cycle of an upshift cycle and storing the data in the memory upshift register means, and for removing the stored data from the memory upshift register means within the period of a memory recirculation cycle and storing the data in a different storage segment which is connected to the memory input connection earlier in a memory recirculation cycle than the storage segment from which the data was read out, the data for all the rows becoming stored in storage segments earlier in the recurring sequence during a relocation cycle having a period equal to an integral number of fields, the data for each row being relocated in the storage segments previously containing data for the adjacent earlier displayed row during the period of an upshift cycle, an upshift cycle having a period equal to an integral number of relocation cycles; incoming information means for supplying data for a new row of characters to the memory means at said input connection of the memory means to store the data in each of the two storage segments originally containing the most recent data at a time during each upshift cycle subsequent to relocating of the most recent data to earlier segments of the recurring sequence; display register means coupled to the output connection of said memory means and being capable of storing data for a single row; memory output control means for reading out data for each row in turn from said storage segments of the memory means during each field of the raster scanline pattern by reading out appropriate segments containing data for each row in turn earlier in the recurring sequence for each succeeding relocation cycle of an upshift cycle and causing the data for each row in turn to be stored in said display register means at an earlier time during the field for each succeeding relocation cycle of an upshift cycle; display register output control means for repeatedly reading out the data for each row from said display register means at the scanline rate for the number of scanlines of a row of characters, the data for each row being read out at successively earlier scanlines during each succeeding field of a relocation cycle; and video signal generating means coupled to the display register means for generating video signals for producing images of a row of characters on the display surface in response to the data for a row being read out of the display register means.