Method and apparatus for generating hardware icons and cursors

An apparatus for generating a hardware icon to communicate with a computer CPU comprising:

• a horizontal control circuit for controlling the width of said icon to be displayed;
• said horizontal control circuit comprises:
• a) a horizontal comparator to compare horizontal counts representing a current horizontal position of a pixel to be displayed with predetermined values representing positions along a horizontal axis;
• b) a horizontal counter triggered by said horizontal comparator to count said horizontal counts;
• said horizontal counter provides a terminating signal to limit the width of said icon when a predetermined number of said horizontal counts are supplied to its input;
• and
• a vertical control circuit for controlling the height of said icon to be displayed;
• said vertical control circuit comprises:
• a) a vertical comparator to compare vertical counts representing a current vertical position of a line to be displayed with predetermined values representing positions along a vertical axis;
• b) a vertical counter triggered by said vertical comparator to count said vertical counts;
• said vertical counter provides a terminating signal to limit the height of said icon when a predetermined number of said vertical counts are supplied to its input.

An apparatus for generating a hardware icon and a hardware cursor to communicate with a computer CPU comprising:

• means for keeping track of and synchronizing a video display's horizontal pixel pulse count for generating both said hardware icon and said hardware cursor;
• means for keeping track of and synchronizing said video display's vertical line count for generating both said hardware icon and said hardware cursor;
• means for storing said icon's desired horizontal position;
• means for comparing said video display's current horizontal pixel pulse count with said hardware icon's desired horizontal position to determine whether said pulse count is equal to or greater than said desired horizontal position, said determination triggers an icon horizontal start signal;
• means for ensuring the horizontal dimension of said hardware icon is within its desired limit comprising means for storing said limit, means for determining when said horizontal dimension of said hardware icon exceeds said limit, and means for outputting an icon horizontal kill signal;
• means for coupling said icon horizontal kill signal with said icon horizontal start signal to determine whether to output an icon horizontal enable signal;
• means for storing said icon's desired vertical position;
• means for comparing said video display's current vertical pixel pulse count with said hardware icon's desired vertical position to determine whether said pulse count is equal to or greater than said desired vertical position, said determination triggers an icon vertical start signal;
• means for ensuring the vertical dimension of said hardware icon is within its desired limit comprising means for storing said limit, means for determining when said vertical dimension of said hardware icon exceeds said limit, and means for outputting an icon vertical kill signal;
• means for coupling said icon vertical kill signal with said icon vertical start signal to determine whether to output an icon vertical enable signal;
• means for coupling said icon horizontal enable signal with said icon vertical enable signal to determine whether to output an icon enable signal;
• means for storing said cursor's desired horizontal position;
• means for comparing said video display's current horizontal pixel pulse count with said hardware cursor's desired horizontal position to determine whether said pulse count is equal to or greater than said desired horizontal position, said determination triggers a cursor horizontal start signal;
• means for ensuring the horizontal dimension of said hardware cursor is within its desired limit comprising means for storing said limit, means for determining when said horizontal dimension of said hardware cursor exceeds said limit, and means for outputting a cursor horizontal kill signal;
• means for coupling said cursor horizontal kill signal with said cursor horizontal start signal to determine whether to output a cursor horizontal enable signal;
• means for storing said cursor's desired vertical position;
• means for comparing said video display's current vertical pixel pulse count with said hardware cursor's desired vertical position to determine whether said pulse count is equal to or greater than said desired vertical position, said determination triggers a cursor vertical start signal;
• means for ensuring the vertical dimension of said hardware cursor is within its desired limit comprising means for storing said limit, means for determining when said vertical dimension of said hardware cursor exceeds said limit, and means for outputting a cursor vertical kill signal;
• means for coupling said cursor vertical kill signal with said cursor vertical start signal to determine whether to output a cursor vertical enable signal;
• means for coupling said cursor horizontal enable signal with said cursor vertical enable signal to determine whether to output a cursor enable signal;
• means for storing data associated with said hardware icon and cursor;
• means for controlling the display of said data associated with said hardware icon and said hardware cursor on different display systems, said output of said hardware cursor data is enable by said cursor enable signal, said output of said hardware icon data is enable by said icon enable signal;
• and
• means for detecting the overlap of said hardware icon and said hardware cursor based on said cursor enable signal and said icon enable signal, said overlap detection triggers an interrupt signal.

A method for generating a hardware icon and a hardware cursor to communicate with a computer CPU comprising the steps of:

• comparing said hardware icon's desired horizontal position with a video display's horizontal pixel pulse count to determine whether said pixel pulse count matches with said desired horizontal position;
• comparing said hardware icon's desired vertical position with said video display's vertical line count to determine whether said line count matches with said desired vertical position;
• ensuring the vertical and horizontal dimensions of said hardware icon are within the desired limits;
• comparing said hardware cursor's desired horizontal position with said video display horizontal pixel pulse count to determine whether said pixel pulse count matches with said desired horizontal position;
• comparing said hardware cursor's desired vertical position with said video display vertical line count to determine whether said line count matches with said desired vertical position;
• ensuring the vertical and horizontal dimensions of said hardware cursor are within the desired limits;
• and
• displaying graphics data associated with said hardware icon and graphics data associated with said hardware cursor together on different display systems.

An apparatus for implementing a display priority scheme to allow a hardware cursor manipulate a hardware icon, said apparatus comprising:

• a priority decoder for determining the display priority between a hardware cursor and a hardware icon wherein said display priority is based on the display priority scheme that a hardware cursor data input has first priority followed by a hardware icon data input and wherein if a hardware cursor is displayed, overlapping portions of said hardware icons is suppressed;
• a selection code triggered by said priority decoder for selecting said hardware cursor over said hardware icon;
• and
• means for multiplexing data representative of said hardware icon and hardware cursor wherein said multiplexing process is responsive to said selection code.