Week 4 Assignment 1: Computer Architecture
Tony D. Everett
Professor Jennifer Merritt
CIS106 Intro to Information Technology
July 28, 2013

Introduction
The use of Information Technology is well recognized. Information Technology has become a must for survival of all business housing with the growing IT trends. The computer is the main component of any Information Technology system. Today, computer technology has filled every scope of existence of modern man. From airline reservations to auto repair diagnosis, from government services databases to manufacturing and production systems that are used by the likes of Pepsi, Kellogg’s and Kraft Foods-everywhere we witness the elegance, complexity and effectiveness possible only with the help of computers. These systems operate using the Von Neumann Architecture.
The Von Neumann Architecture and Importance
The von Neumann architecture is a design model for a stored-program digital computer that uses a processing unit and a single separate storage structure to hold both instructions and data. The instructions are executed sequentially which is a slow process. One shared memory for instructions and data with one data bus and one address bus between processor and memory. Commands and data have to be fetched in sequential order (known as the Von Neumann Bottleneck), limiting the operation bandwidth. Its design is simpler than that of the Harvard architecture. It is mostly used to interface to external memory. Neumann architecture computers are called control flow computers because instructions are executed sequentially as controlled by a program counter. To increase the speed, parallel processing of computers have been developed in which serial CPU’s are connected in parallel to solve a problem. Even in parallel computers, the rudimentary structure blocks are Neumann processors. It is named after mathematician and early computer scientist John von Neumann.
Such a computer utilizes a universal machine, and the common referential model of categorizing chronological architectures, in contrast with parallel architectures. The "Turing" machine, another common term for universal machine, was developed in 1936 by British mathematician Alan Turing, who termed it an "a-machine" (automatic machine). Turing’s accomplishment recently was named greatest British innovation of the 20th Century. “We owe him a huge debt, his Universal Machine idea laid the logical and mathematical foundations of the technology you're using to read this”, said Stephen Fry. (http://www.dailymail.co.uk) The Turing machine is not intended as everyday computing technology, but somewhat as a hypothetical device demonstrating a computing machine. Turing machines help computer scientists understand the limits of mechanical computation.
Von Neumann architecture is an early, effective type of computing configuration. It mainly consists of memory chips that are able to both hold and process data. Each chip has the capability to accomplish different responsibilities, contingent upon how it is affected by the operation performed before it. Per the Von Neumann architecture each computer would have memory, devices for output and input, a central control, a place for essential arithmetic, and external storage. Computers with Von Neumann architecture are known as stored-program. This means that the computer does not need external switches or other influences in order to run. All instructions and data are stored in random-access memory (RAM).
Before the Von Neumann architecture, computers were basically designed rather than being programmed. Once a machine was amassed, it could only accomplish one task. In order to change what the computer did, it was needed to rewire, add components, or then alter the physical configuration of the machine.
Although many existing computers remain to have some base in Von Neumann architecture, some programmers have begun to abandon the theory for more efficient models. A sensation recognized as the Von Neumann bottleneck is one of the key problems with the structure. The issue with the bottleneck is that the operations which process information and data share the same bus, which is the transportation scheme for these fundamentals. This disturbs the effectiveness and overall capability of the system.
In recent years, the Von Neumann architecture has frequently been supplanted with Harvard architecture. It is also a stored-program type of architecture. Harvard architecture manages storage, data, and instructions in a similar way, but has more resources for transporting information. The structure has dedicated data buses for transporting instructions and memory, so that more functions can operate at the same time. While the Harvard architecture has grown in popularity, there are still some who prefer the simpler Von Neumann architecture, which can be a more accessible format for beginning computer programmers in particular.

The System Bus
A current system can be perceived as involving just two classes of bus: a System Bus, joining the CPU to main memory and Level 2 cache, and a number of I/O Busses, linking numerous outer devices to the CPU the latter being linked to the system bus by a bridge, implemented in the processor’s chipset.

A front side bus replaced the single system bus in Dual Independent Bus (DIB) architecture systems, for transferring data between the CPU and main memory, and between the CPU and peripheral buses and a backside bus for retrieving Level 2 cache. The use of dual independent buses increases performance, permitting the CPU to access data from whichever of its buses concurrently and in parallel.
Boolean Operators
Boolean algebra was developed by George Boole as a logical system which utilizes truth tables to specify true/false output established on all potential true/false inputs. Boolean operators are part of this system that is used to test two logical values. The basic Boolean operators are AND, OR, and NOT. The AND input uses two values as input and returns a true value only if both values are true. The OR input works with two operands also, but returns a true value if either operand is true. The only operator that works with a single input is the NOT and its function is to reverse the input. Each of these operators is basic representation of transistors, which in turn are group together to create expressions that symbolize circuits in the calculations of a computer system. There are other operators that have unique functions, but the AND, OR, and NOT are the core operators in Boolean algebra.
Memory and Storage
ROM (read-only) and RAM (random access) are the two basic forms of memory in a CPU. ROM is traditionally permanently embedded to the CPU’s hard drive, but there is times where the ROM can be modified under certain situations. ROM does not change with the turning on/off of the CPU. However, RAM stores data as it is typed to the computer screen and it is not saved until the user saves it. RAM does not have to be accessed in order; it can use any location of memory by providing and address to identify the location. DRAM and SRAM are both types RAM that provides faster speeds than RAM.
Hard drives, CD’s and DVD’s are all forms of mass storage. They all provide a higher amount of storage than both ROM and RAM and can be purchased at a better price. USB devices or flash drives, as they are sometimes called is a portable and smaller form of storage that can be used to stored data and removed to transfer data to other CPU’s.

References
Suzannah Hills, (March 26, 2013), Alan Turing's Universal Machine is named greatest British innovation of the 20th Century, Dailymail.co.uk, Retrieved July 28, 2013, www.dailymail.co.uk/sciencetech/article-2299245