The computer is an electronic device that operates under the control of instructions that are stored in memory. The idea of storing memory or instructions within the computer came from John Von Neumann. Von Neumann architecture can be described as a stored program design. A stored programmed design means that the program that operates the computer and the instructions that carry out the program are stored on the computer in one location, memory. By stored program design, the computer doesn’t have to go through strict process to be reprogrammed, or to perform multiple functions. The basic design of the computers is founded on the architecture. The Von Neumann model consists of five components that work together to make the computer work. There is an area for memory to be held and processed called Random Access Memory (RAM). There is a control unit, which manages the process of moving data and program into and out of the memory, and also executes the programs instructions, one by one. There is an input and output which is the computers connection to the user. The arithmetic logic unit is responsible for carrying out calculations or instructions. Another important concept of the Von Neumann architecture is the bus, which is a set of wires that allow for communication between the CPU, memory and input/output devices.
Von Neumann architecture uses a system bus to communicate data between the different parts that need to communicate with each other inside of the computer. The system bus is made up of the data bus, the address bus, the control bus, and a power bus. A bus is simply a circuit that connects one part of the motherboard to another. It allows for transferring of data between components inside of the computer. The system bus moves information back and forth from the memory to the processor, it also moves information back and forth from the I/O devices. This circuit, or bus, is the communication system that is used within the computer. The instructions required to operate the programs on the computer are able to be carried out because of the ability to send electrical pulses or code, across the bus system wires which communicate data needed to perform operations. The buses operate within a set of guidelines or protocols, which govern the electrical signalling. The system bus is needed within the computer because without it, it would be difficult to transfer the instructions required to make the computer programs operate.
Computer based calculations are carried out by the process of using Boolean operators. Boolean operators consist of using the logic of AND, OR, and NOT. These three operators are used to carry out the algebraic expressions that can be translated into instructions, also known as Boolean algebra. When a computer is programed to launch the screen saver, the instruction may read something like, if there hasn’t been any activity for five minutes AND the mouse hasn’t been moved AND the keyboard hasn’t been typed on then activate the screen saver. The code is used to represent words, the Boolean operators are used to make the words work together, and the logic is put together to produce an outcome which is the functionality of the computer.
The fetch execute cycle is performed by “fetching” data from the various memory and storage locations within the computer and executing the instructions that are stored in the memory. There are two categories or memory, primary and secondary. Primary memory consists of ROM which stands for