Computer Architecture Essay

1. Describe Von Neumann architecture and explain why it is important. The Von Neumann architecture explains the architecture of an electronic computer. It is attributed to be root of every electronic computer that has ever been made. According to Von Neumann architecture an electronic computer has Control Unit, Arithmetic Logic Unit, Memory & Input / Output Devices. The following diagram shows this architecture:- Memory: – Memory holds both data and the instructions. Control Unit: – The Control Unit manages the movement of data and instructions in and out of the memory and also deals with sequential carrying out of the programs. Arithmetic Logic Unit: – Carries out all the calculations on the data. Apart from operations like addition, subtraction etc, ‘greater than’, ‘less than’ etc would also be provided. Input / Output: – Input/output devices to feed into the data and take out the data. This component served interaction with the human who was operating the device The most basic principle of development of Von Neumann architecture was that it not just stored the data and the computation that was involved; it also stored the set of orders and instructions that had resulted in the computation. The entire set of instructions were stored in what is called as ‘registers’ and the control unit used to process this in a sequential manner – which means one at a time. In this architecture the instructions were encoded into numeric form and the data as well as the instructions were then stored in the memory. The Von Neumann Architecture is important because it led to the development of the earliest computers. Even the computers we see today, that are fifth generation and have a drastically different architecture, draw their parallels from Von Neumann Architecture. Obviously there has been lot of improvements. However, the base of having memory, control unit, input / output devices still remains integral to all the machines. Von Neumann architecture can hence be easily regarded as mother of all computer architectural designs. 2. Explain what a system bus is and why it is needed. The system bus is the pathway over which the data travels between the CPU and the rest of the components on the motherboard. The system bus speed is defined as the capacity to move the data through the system, as it is the speed that connects the different parts of the system. The front-side bus (FSB) is that part of the bus which is responsible to carry the data between RAM and the CPU. FSB is the part that usually has the greatest effect on the performance of the system. A system with high-performance processors and components would need to have a fast front-side bus. Bus speed is quite important and can have a significant impact in the performance of the machine. The data in a system is stored, manipulated and processed in the system memory. The system needs to move this information in and out of memory, and at the same time, a track of which data is stored at which location need. This entire info travels using the system bus. If the bus speed is low, there will be a very low transmission data speed, leading to the computer working very slowly. We know that in all the modern systems that we use, the processor is running at a speed that is much faster than the memory bus. If we compute the ratio of processer speed to bus speed (something called as bus multiplier), we will find that the lower the multiplier the better it is. If the multiplier is large, it would mean that the bus speed is slow as compare to the processor speed, in which case the processor will remain idle. On the other hand, if the bus speed is higher, then more data can be fed to the processor resulting in lower latency (time to start a request). 3. Summarize the use of Boolean operators in computer-based calculations. Boolean Operators are the most popular operators used for computer based calculations. Boolean operators are simple words (AND, OR, NOT or AND NOT) which are used to carry out these calculations. Together, these keywords help in finding, joining or excluding a particular keyword in a search and hence arrive at results efficiently. These operators and their use can greatly help in saving time by doing searches for getting to ‘on-target’ results – which are more relevant and accurate to the questions/needs that are posed. Every different search engine makes use of Boolean operators in varying fashion. While doing Boolean based calculations, a lot of proximity operators can be used to combine strings which can then help with the search. A brief overview of various operators is given below:- AND This Boolean operate requires both the terms to be in each item returned. For example, if only one of the term is contained in the document and the other is absent, the item is excluded OR This Boolean operator would return either term (or even both the terms) NOT While using this Boolean operator, the first term is searched, and then any records containing the term after the operators are subtracted from the results. Using Parentheses to include different strings will help in giving more customized and accurate results for the operation. 4. Categorize the various types of memory and storage. Computers need to have a storage space and memory units to store information and to run programs. There are various types of memory and storage, with various specifications and different purposes. These different types of memory and storage are:- Random Access Memory (RAM) RAM stores the data on a temporary basis, and as such it can be quickly/promptly accessed by the processor. This information, which includes both the application data and the data related to operating system, is loaded from the hard disk of the computer. The catch however is that as soon as the system is switched off, all the stored information is lost. Read Only Memory (ROM) Unlike RAM, ROM is active, even if the system is turned off – thus making it somewhat a permanent non-volatile storage memory. The contents of ROM cannot be modified. ROM has all the data which should be present so that the computer can carry out the normal functions.. Cache Cache is a more responsive memory than RAM. The CPU, in case of Cache, for finding the required information the CPU first searches the cache memory before searching the central memory storage area Computer Hard Drive This has a set of devices that are integral components of data storage components in the CPU. This particular memory has different ranges and a particular user may chose the size of the memory. The hard disks can store a very large amount of information, including photos, videos, music, documents, programs and more and this memory remains even after your computer is turned off. External hard disks An external hard disk is a great way to store more digital photos, videos, music, and other large files. It can add huge volume to the storage space on your computer’s internal hard disk. Flash Memory Unlike the other storage and memory options, this is a portable storage and felicitates a convenient data transfer between two computers. Easy deletion and re-programming of data is possible as per the user’s requirements. References Backus, J. 1978. Can programming be liberated from the von Neumann style? A functional style and its algebra of programs. Communications of the ACM 21, 8, (August), 613-641. Myers, G. J. 1982. Advances in Computer Architecture. John Wiley & Sons, New York. von Neumann, John (1945), First Draft of a Report on the EDVAC, retrieved August 24, 2011 Linda Null; Julia Lobur (2010). The essentials of computer organization and architecture (3rd ed.). Jones & Bartlett Learning. pp. 36,199–203. ISBN 978-1-4496-0006-8.