Abstract: In order to achieve an interpolation display of a display object existing between two adjacent planes according to the triangulation when digital data on the two adjacent planes is given, the data items on the two planes are grouped into a plurality of connected components, respectively, and several connected components on the first plane are projected onto the connected components on the second plane. Thereafter, a sequence of points enclosing each one of the projected components are selected, and the selected point sequence is corresponded to a sequence of boundary points which enclose one of the connected components which contains the subcomponent whose projected image onto the connected components on the second plane is equal to the projected component. Then, by using every corresponding pairs of the sequences, the triangular faces are generated.

Abstract: An operating system (OS) is divided into units (OS processes) which are concurrently executable. When the processors concurrently request the execution of one OS process, data indicating that the requested OS process is in a ready state is loaded into a memory. The other processors repeatedly make an access to the data during the course of the execution of the user's task to check to see whether the ready-state OS process is present or not. A processor when detecting the ready-state OS process ceases the execution of the user's program and executes that OS process.