The device of this invention controls a cathode ray tube (CRT) in order to display desired images on a selected region of the screen. Locations on the screen are identified by horizontal and vertical addresses. The device comprises means for storing information to be displayed on the screen of the cathode ray tube and a control means. The control means selects information for display and generates a display control signal for controlling the cathode ray tube. The display control signal causes the cathode ray tube to display the selected information and also indicates a predetermined vertical or horizontal address. When the display control signal indicates a horizontal address, the control means displays selected information only in the region of the screen above or below the horizontal address and not in the remainder of the screen. When the display control signal indicates a vertical address, the control means displays selected information only in the region of the screen to the left or the right of the vertical address and not in the remainder of the screen.

Apparatus and methods for selectively controlling by graphics environment window the characteristics of an overlay common to multiple-windows while operating within the context of a conventional RAMDAC overlay control architecture. Window specific overlay control is accomplished by concatenating the window, masking and overlay data as an address to a mapping memory. The bit content of the mapping memory is controlled directly by the general purpose processor to selectively refine the relationship between the concatenated input as an address and the mapping memory output as the state conveyed to the overlay control of the RAMDAC. A common overlay is thus selectively modifiable by window.

The invention is an object-oriented graphic interface for use in computer controlled display systems. A central processing unit (CPU) is provided and is coupled to a display for displaying graphic and other data. The CPU is further coupled to a cursor control device which permits a user to selectively position a cursor at a desired location on the display, and signal the CPU of selections in accordance with the teachings of the present invention. Buttons are generated by the CPU and displayed which correspond to either a single function to be executed by the CPU, or a button stack which has associated therewith a plurality of functions disposed on a menu. The menu includes a plurality of buttons and/or button stacks. The menu also includes a first icon, which presently is in the form of a push pin. The placement of the cursor over the push pin and releasing the first switch on the cursor control results in the CPU converting the menu into a window. The CPU then retains this window on the display regardless of other display operations performed. The window may be dismissed, at any time, by placing the cursor over a push pin provided on the border of the window and momentarily depressing and releasing the first switch on the cursor control device. In addition, if the user once again places the cursor over the push pin and momentarily depresses and releases the first switch on the cursor control device, then the window will be dismissed after the execution of any of the button or button stacks disposed within the window.

An apparatus and method is disclosed which has application for use in computer controlled display systems, and in particular, display systems having object oriented graphic interfaces. A central processing unit (CPU) is provided and is coupled to a display for displaying graphic and other data. The CPU is further coupled to a pointer control device which permits a user to selectively position a pointer at a desired location on the display, and signal the CPU of selections in accordance with the teachings of the present invention. Buttons are generated by the CPU and displayed which correspond to a single function to be executed by the CPU, a window button which displays a pop-up window, an abbreviated menu button or a menu button which has associated therewith a plurality of functions disposed on a menu. The menu includes a plurality of menu items. A menu button must be provided with a menu item which is a default function which is automatically executed by the CPU when a predetermined signal is provided by the user through the pointer control device. To select and execute a menu button default, a user places the pointer over the desired menu button and momentarily depresses a switch on the pointer control device, the default function is then executed without the need to choose the menu item function from the menu button menu. Placement of the pointer over the menu button and depressing another pointer control switch results in the display of the full button menu.

A graphical user interface method wherein a user can retain frequently used menus on the display screen in an intuitive manner. A computer system is coupled to a display for displaying graphic and other data and to a pointer control device which permits a user to selectively position a pointer on the display and signal selections with a switch. Graphical menu buttons are displayed on the screen which correspond to menus displaying further functions. When a menu button is selected by the user, a menu appears in a rectangular box containing an icon of a pushpin and a plurality of menu choices which can be selected. If the user places the pointer over the pushpin icon and then releases the pointer control device switch, the icon of the pushpin is then modified so it appears that the pushpin has "pinned" the menu to the screen. The temporary menu box is converted into a permanent window which remains on the display regardless of other display operations. The user may dismiss the menu window at any time by placing the pointer over the pushpin icon and momentarily depressing and releasing the switch on the pointer control device. The invention therefore provides an intuitive means for retaining frequently used menus on a graphical user interface screen.