Home computer and game apparatus

A system for providing a display signal to a raster scan display for displaying thereon a matrix of discrete picture elements, the system comprising:

• a random access display memory having a unique storage location for each discrete picture element of the display for storage of digital memory data signals representative of the picture elements of the display;
• a processor containing means for receiving a plurality of groups of picture element signals, each picture element signal comprising a memory address signal and a memory data signal which together correspond to one particular picture element of the display, each group of picture element signals corresponding to a plurality of picture elements representing a symbol located at a predetermined location on the display, said processor generating control signals, said control signals including background data signals representative of background picture elements;
• first addressing means for sequentially and repetitively addressing the storage locations of the display memory, reading the memory data signals stored therein, and supplying the display signal to the display for displaying thereon the picture elements representative of the memory data signals stored in the display memory;
• transfer means for transferring picture element signals from the processor to the display memory whereby memory data signals corresponding to said picture element signals are stored in memory locations of the display memory as determined by the memory address signals corresponding to said picture element signals;
• and
• background signal means having a register operatively coupled to the processor for receiving therefrom background data signals for storage therein, and operatively connected to the first addressing means for supplying the background data signal thereto, the background signal means including selector means operatively coupled to the first addressing means and the register for substituting the background data signals stored in the register for memory data signals when the first addressing means addresses select storage locations of the display memory whereby the first addressing means supplies the display signal to the display representative of the background data signal when the first addressing means addresses the select memory locations of the display memory.

A variable interrupt system for providing a display signal to a raster scan display for displaying thereon a matrix of discrete picture elements, the system comprising:

• a random access display memory having a unique storage location for each discrete picture element of the display for storage of digital memory data signals representative of the picture elements of the display;
• a processor comprising means for receiving a plurality of groups of picture element signals, each picture element signal comprising a memory address signal and a memory data signal which together correspond to one particular picture element of the display, each group of picture element signals corresponding to a plurality of picture elements representing a symbol located at a predetermined location on the display, said processor generating control signals;
• first addressing means for sequentially and repetitively addressing the storage locations of the display memory, reading the memory data signals stored therein, and supplying the display signal to the display for displaying thereon the picture elements representative of the memory data signals stored in the display memory;
• transfer means for transferring picture element signals from the processor to the display memory whereby memory data signals corresponding to said picture element signals are stored in memory locations of the display memory as determined by the memory address signals corresponding to said picture element signals;
• and
• variable interrupt means operatively connected to the processor for receiving therefrom a control signal representative of a particular row of picture elements on the display, the variable interrupt means generating an interrupt signal for transmission to the processor when the first addressing means addresses predetermined memory locations of the display memory which correspond to the particular row of picture elements.