Cursor control matrix for computer graphics

Claim 1

A computer-controlled industrial process control system provided with a plurality of controllable elements each constituted by adjustable means such as a valve, a switch or a control knob and having a computer terminal providing on a screen a graphics display of the system being controlled, each of said controllable elements being represented on the display by an action point whereby a plurality of such action points are dispersed at various positions on the display, and an arrangement making it possible for an operator viewing the screen to select any action point thereon regardless of its position so as to carry out, with the controllable element related thereto, an action appropriate to the selected point; said arrangement comprising: A. a cursor movable on the display to provide a distinctive symbol thereon; B. a key matrix manipulatable by the operator to cause the cursor to occupy a position coinciding with any action point on the display, said matrix being constituted by a center key representing home surrounded by eight keys, each having an arrow thereon, the respective arrows on the eight keys being directed to the major axes of a compass rose; C. means to interlink the key matrix with the cursor to render the center key effectively coincident with a currently selected action point on the display which is then the center of the compass rose, whereby the operator, in order to select a new action point then presses the arrow key which most closely points in the compass rose direction of the desired new action point to cause the cursor to jump one step to the newly selected action point; but if more than one action point lies between the currently selected point and the desired point, the operator must then repeatedly press said arrow key to cause the cursor to jump one step at a time until the cursor rests on the desired action point, said means being constituted by a software routine in which each action point and its coordinates on the screen are entered into a table, whereby each time one of the arrow keys is pressed, a software routine is executed which accepts as its input the currently-selected screen position and one of the eight arrow key directions, and then generates as its output the next screen position to be jumped to, this jump being effected by examining the table of coordinates for the closest entry in the designated direction; and D. an alphanumeric keyboard associated with said computer adjacent to said key matrix whereby the operator may control the selected action point from the keyboard.