immediate access store

The memory, or store, is the part of a computer system where data and instructions are held for use by the central processor and where the central processor puts data it generates. The computer store is made up of a large number of identifiable units or locations. Each location has a unique label, called an address, which is recognisable and used by the central processor. Those locations that can be addressed directly by the central processor are called the main store, immediate access store (IAS) or primary store. The contents of IAS disappear when the power to the computer is switched off.