Stored Program Control Most computer systems today are stored program control systems. This means that the processor executes instructions which are stored in a memory subsystem. SPC systems are popular, because the processor does is simply changed by altering the instruction in the memory system. This makes for a general purpose computer system, capable of performing a wide variety of different tasks dependant upon the stored program contents. Computer Memory Memory contains data or instructions for the processor to execute.
All memory has common features.
Address Locations Memory consists of a sequential number of locations, each of which are a specific number of bits wide. The more number of bits per location affects the speed at which data can be moved from one location to another in a computer system. In general, the more bits per location the faster data can be transferred. The processor selects a specific address in memory by placing the address on a special multi-bit bus called the address bus . The value on this address bus is used by the memory system to find the specific location within the chip which the processor is requiring access to.