Abstract: Allocation information for a random access memory is stored in a separate memory or memory area. Each memory block in the RAM is divided into 2.sup.n equal-sized spaces, and a memory allocation tree structure is established which stores, in a separate random access memory (which can be a dedicated, non-allocable section of the first random access memory), a single space availability indicator at a first level representing 2.sup.n equal-sized spaces, a pair of pair of space availability indicators at a second level each representing 2.sup.n-1 equal-sized spaces, and so on until a plurality of space availability indicators are placed at a suitable lower level tree structure such that each represents a single equal-sized space. When a request for allocation of memory space is made, the allocation information for a memory block is checked to determine if a space availability indicator at the level which could accommodate the request is set to the first value. (If not, a different memory block is checked.

Abstract: A stored program electronic digital computer has a control system for the computer. There are a plurality of processes in the computer. There are four stored program controllers in the computer which operate in different processors within the computer system. There is a master controller, a command controller, a task controller, and a disc I/O controller. These four controllers operate in a hierarchy of control. Each controller exercises control over a given level of work in the computing system.