College of DuPage [email protected]. Computer and Internetworking Technologies Computer Science (CIT) Scholarship 10-1-2010 Computer Hardware Basics Clyde Cox College of DuPage, [email protected] Follow this and additional works at: http://dc.cod.edu/citpub Part of the Computer Sciences Commons Recommended Citation Cox, Clyde, "Computer Hardware Basics" (2010). Computer and Internetworking Technologies (CIT) Scholarship. Paper 2. http://dc.cod.edu/citpub/2 This Article is brought to you for free and open access by the Computer Science at [email protected].. It has been accepted for inclusion in Computer and Internetworking Technologies (CIT) Scholarship by an authorized administrator of [email protected].. For more information, please contact [email protected]. CIT 1100 Chapter 1 Introduction to Computers Digital computers have been around for over 50 years in many different sizes and configurations. When the first mainframe computes were designed, it was thought that all the computing needs could be accomplished with as few as 5 machines. Given the cost and complexity of the first systems, it’s understandable why people felt that way. As far reaching an effect as the large mainframe had on the industry, it would soon be eclipsed by the inexpensive home computer. You would be hard pressed to think of a business that has not been affected by computers. Large corporations that once relied totally on expensive mainframes began to put computers onto everyone’s desk. Decentralizing computers made people more productive and with the addition of local area networks allow people to share data and communicate in ways that were once unheard of. E-mail has almost eliminated our use of the fax machine and allows instant communication worldwide. The cost of computers has dropped so dramatically in the past few years that they are almost considered disposable. With home system prices as low as $300.00, you might ask why anyone would even bother repairing old systems. Wouldn’t it be cheaper to buy a replacement rather than pay to have the system fixed? Especially when you consider that the new systems have twice as many new features as last year’s model! So why would anyone want to take the time to learn about computers? To answer that question, you need to define the user. Computer users can be basically broken into two segments, the home user and business user. Home users usually have enough knowledge to set up a new system, they simply plug color coded plugs into color coded ports and everything usually works. Most home users lack the knowledge to do much more than that; after all, they purchased the computer to connect to the internet, send e-mail, play games, and help their children with their homework. When it comes to knowing about Page 1 of 11 9/5/2010 CIT 1100 Chapter 1 Introduction to Computers upgrading memory, replacing or defragmenting hard drive most would rather have someone else do it. Businesses view computers differently; they see it as a tool used to increase productivity. They know computers will improve the bottom line of the company, but they also know there is a cost involved. Users must be trained to use new equipment that is constantly evolving. Preventative maintenance, networking, and printing is a daily issue with even small companies. It doesn’t matter to a small company that the system they use only cost $500.00 when it crashes and has their accounts receivable information or payroll stored on it. Also consider the cost to the company in terms of the security of the data stored on a system. According to the U.S Bureau of Labor Statistics the job market for Network & Computer Systems Administrators is expected to grow much faster than the average with and increase over 23% by the year 2018. Job Outlook Employment is expected to grow much faster than the average, and job prospects should be excellent. Employment change. Overall employment of computer network, systems, and database administrators is projected to increase by 30 percent from 2008 to 2018, much faster than the average for all occupations. In addition, this occupation will add 286,600 new jobs over that period. Growth, however, will vary by specialty. Employment of network and computer systems administrators is expected to increase by 23 percent from 2008 to 2018, much faster than the average for all occupations. Computer networks are an integral part of business, and demand for these workers will increase as firms continue to invest in new technologies Source: http://www.bls.gov/oco/ocos305.htm#outlook Page 2 of 11 9/5/2010 CIT 1100 Chapter 1 Introduction to Computers Getting started, opening up the system case Safety The first thing you should notice on the back of any computer is that there are no warning labels telling you that there are “hazardous voltages inside”, or that the unit contains “no user serviceable components” and maintenance should be done only by a “qualified service technician”. On the back of every other electrical appliance, there is a warning label telling the end user not to open the case. Most appliances were never designed for the end user to remove the back since the inside of the appliances might have exposed power that could be lethal if accidentally touched. Then why isn’t there a warning label on the back of a computer? Unlike other electrical appliances computers have an internal power supply that is completely enclosed inside the case. This power supply is completely sealed and any hazardous voltages are safely contained inside it. An end user who opened the computer located, the power supply, and attempted to open it would see a warning label. So it’s important to remember that there are no hazardous voltages exposed inside a computer, unless you also open the power supply which is not a good idea. Monitors are also devices that should only be left to technicians certified to work on them due to the dangers of hazardous voltages. The manufacturers of computers realized that non-technical users would be required to open computers to install add-on devices, so every effort was made to make the inside of the computer safe to work on. Hazards inside the computer Knowing that you cannot be electrocuted if you put your hands inside a computer should be reassuring, but there are many other hazards you need to be aware of once you remove the cover. Static Electricity is something we have all experienced at one time or another, usually in the winter when the furnace is running and the humidity inside you home is very low. If you walk across a carpet and touch a Page 3 of 11 9/5/2010 CIT 1100 Chapter 1 Introduction to Computers doorknob, you can feel the effects of static electricity. Depending on the conditions, you might not only feel it, but you might hear the discharge or even see a spark. Static electricity will not harm you unless you get struck by lightning which has much more voltage than you could build up by walking across a carpet. Static electricity can be devastating to a computer even at voltages lower than the average person could detect. When you consider that the average person cannot feel the effects of static electricity unless they manage to build up about 3,000 volts before they touch the doorknob, a component inside you computer could be damaged with as little as 30-50 volts. You could damage a component and never realize it. The worst part about this sort of damage is that the effects may take time before the component fails. It’s similar to taking a piece of metal and bending it back and forth, eventually the metal will weaken and break. If you don’t take proper precautions when handling components, you could be damaging them when you install them. Static electricity facts / Figures o It takes approximately 3,000 volts of static electricity before an average person can feel the effects o Walking across a carpet in a room with low humidity can generate as much as 35,000 volts of static electricity o Walking across a vinyl floor can generate 12,000 volts of static electricity o Styrofoam cups can generate 14,500 volts of static electricity o Electronic components can be ruined by as little as 30–50 volts of static electricity o Loose components like the CPU and Memory are more prone to static damage than entire circuit boards like a plug-in modem or a motherboard o When holding a circuit board always hold it by the edges, similar to the way you would hold a photograph, try not to touch anything metal Page 4 of 11 9/5/2010 CIT 1100 Chapter 1 Introduction to Computers o New devices are shipped in specially designed anti-static bags; these bags should be used to store components when not in use or when carrying components Sharp Edges Some computer cases are stamped out of sheet metal and the insides can have sharp edges. If you are working inside a computer check to see if the case has any sharp edges and protect yourself and electrical wires from them. Heat One of the major causes of premature failures of computers is heat. All computers have fans built into the power supply, and all CPUs since the 80486 have had fans connected to them as well. The air circulation inside a computer is designed to allow cool air to be pulled in by the fans and maintain a proper temperature inside the computer.