Kaitlin CSC231 PC Demolition Lab

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Introduction

The goal of the lab was to take apart a computer and identify each of the parts and then figure out what each part did within the computer. We took apart a Dell Desktop PC that was no longer functioning. We were able to identify parts within the computer including the processor, motherboard, memory and many others.

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Parts

Fan

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The fan helps the computer to remain cool as the power supply, CPU, and motherboard can generate a lot of heat. Computers usually have several fans working to keep the computer cool. Most computers usually have one fan that intakes cool air into the computer. The main fan is often located near the power source or processor to keep air circulating around these parts and keep them cool. Computers usually have another fan to blow out the hot air within the computer from the excess heat that builds up as the computer runs. [1] The fan is an important part of the PC, without it a computer can get overheated which can damage some of the more sensitive parts of a computer. The computer we took apart had one fan in the back located near the power supply.

Power Supply

This image shows the I/O ports and the power supply. The power supply is the metal box that is being taken apart in the backgroud

The power supply gives power to the computer that allows it to run. The power supply converts the AC power that is available from from a wall plug and converts it to DC power to use within the computer. Advanced Technology Extended (ATX) sets the standard for computer power supply to allow for interchangeable parts within a computer and still have them receive the correct amount of power. A computer similar to the one we took apart would have a power supply with an output around 500 Watts. Computers that are used for gaming, graphics work, or other more intensive activities need more energy. Power supplies are about 70% to 75% efficient, using 75% of the power that is converted from AC to DC. The remaining 25% escapes and produces heat which is why fans and heat sinks are necessary within computers. [2]

I/O Ports

Computers now have many different devices that they can support. In the picture we can see the Dell we took apart had USB Ports for a Universal Serial Bus connection which could support any number of devices. There are connections for adding a keyboard, monitor, and mouse which would allow for a user to communicate with the computer. There are also ports for speakers and microphone which along with the sound card allow for the computer to play sound and capture sound. The Dell also had ports for a monitor to connect and other display devices. The network card (ethernet port in the picture) is located near the other I/O ports.

Cables

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The Dell computer we opened up had multiple cables connecting parts throughout the PC. The cables in the computer connect the motherboard to all of the components allowing for data to travel between the two. Additionally, the power supply is connected by cables to every component that needs power.

Hard drive

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The hard drive of a computer stores the data of the computer in memory even when the computer is not powered. The hard drive contains one or more platters each of which has a thin magnetized layer on top of it and a read-write head that rests just above the platter. The read-write head magnetically reads and writes the data to the hard drive. The head can actually harm the hard drive if it brushes against the platter. [3] The hard drive we removed from the Dell PC was 80 gigabytes and made by the company Seagate. Computers today can have hard drives up to 1 Terrabyte (1000 Gigabytes) in size. The hard drive we removed also had all the pins that connected it to the motherboard bent or broken. This is one way to prevent the hard drive from being used on another computer to access the data. The hard drive is connected by a cable to a host bus interface adapter which allows the processor to be able to access and control the hard drive.

RAM

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RAM also know as Random Access Memory stores data used by the microprocessor. Data is stored on the RAM when it is received at the next open byte. There is an index that stores the locations of all of the data stored within the RAM at any given time. A memory chip of RAM is very similar to a microprocessor as it is made up of an integrated circuit that has pairs of transistors and capacitors. Each pair is known as a memory cell and can store one bit of data. The capacitor decides what data is being stored (if the capacitor has a full charge a "1" is stored, if there is no charge a "0" is stored). Energy is used to store the data in RAM and is needed to continue storing the correct data. Unlike a hard drive, RAM cannot store data when there is no power. drive. [4] [5] A computer similar to the one we took apart could have anywhere from 3GB to 6GB of RAM. The computer we took apart also had a few free slots on the motherboard where extra RAM could have been added to increase the amount that could be stored.

CPU

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The Central Processing Unit (or CPU) is the part of the computer that takes commands from programs and executes them. It can access the memory and the other I/O devices within the computer. This part is also known as the microprocessor within a computer. The speed of the CPU has increased over the years from a few megahertz to now a few gigahertz. A Dell computer using an Intel microprocessor similar to the one in the computer we took apart could be between 2.5GHz and 2.93GHz. [6] The microprocessor can create a lot of heat because it is involved in performing many complex operations.

Battery

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The battery is quite small and is not used, for powering the computer itself since that is the job of the power supply. The computer has a battery to power a chip the runs a Real Time Clock in order to keep the date accurate when the computer is off. The battery is located on the motherboard. [7]

Motherboard

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The motherboard is one of the most important parts of a computer. The main parts of the computer including the microprocessor and RAM are all attached directly to the board. I/O devices, such as the hard drive, are connected to the motherboard with cables to be able to get power and be able to read and write data.

Network Card

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The network card allows a computer to connect to a network whether it is a local connection of a few computers in an office or a connection to the Internet. On the outside of the computer there is a port for the Ethernet cord to connect to. The card has the MAC address which is individual to each networking card. This address is burned into the ROM on the network card and cannot be changed. There are a few ways the network card can communicate to the processor to send data. The microprocessor can poll and see if the card is in use, place the card's address on the address bus and gather data, or the card can interrupt the microprocessor when it needs to transfer data. [8]

Floppy Disk Drive

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A floppy disk drive is able to read from and write to floppy disks. Floppy disks are small disks that are covered in magnetic oxide and contained in a square plastic shell. Floppy disks were introduced for commercial use in 1971 and were one of the original methods of externally storing data. A computer could have an operating system stored on one or more floppy disks when hard drives were still expensive for computers. Throughout the 1980s and 1990s floppy disks were popular for data storage. With the introduction of writable CDs and DVDs and USB flash drives the use of floppy disks has decreased in the last decade. [9]

Zip Drive

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The zip drive is a disk storage system introduced in 1994. Zip disks could hold 100MB when they were first released. Over time, the amount a zip disk could hold increased to 750MB. The computer we took apart did still have a zip drive, meaning it was probably created in the late 1990s. These drives are no longer used as writable CDs and DVDs are able to hold larger amounts of data. Once USB flash drives became popular in the early 2000s, zip drives fell out of use. [10]

CD Drive

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An external media source that allows compact discs to be accessed by a PC. The drive uses laser or electromagnetic waves to read and write data to compact discs. CDs and DVDs are among the new devices that have replaced floppy disks and zip disks. CDs and DVDs are often used for installation disks of software for computers because of the higher data storage. The Dell computer we took apart was able to read and write to DVDs as well as CDs. [11]

Heat Sink

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Heat sinks within a computer are very important. A heat sink takes the heat that is generated from a component and dissipates it into the air around it. A microprocessor, a component, within a computer needs a heat sink to prevent overheating. Heat sinks can be in many different shapes and are often made of aluminum alloy which is a good thermal conductor. The heat sink for the processor in the Dell computer was connected to the motherboard with z-clips which are more sturdy then other options for attaching heat sinks. The clips also help with the thermal conductivity of the heat sink. There was another larger heat sink within the power supply that helped it from overheating from the large amount of heat produced by the energy. Pictured here is the heat sink from the power supply. [12]

Sound Card

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The sound card controls the input and output of sound on the computer. The sound card converts data digital to analog output for the speakers and from analog to digital from the microphone. The sound card can produce sound from programs on the computer and have it played though other devices such as headphones or speakers. Microphones are used to record data and are used for programs such as voice recognition programs or voice-over IP. [13]

Graphics Card

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The graphics card is responsible for generating images on a display. Most computers that are for basic use have the graphics processor located on the motherboard and have the same chips as the CPU (an Intel processor would usually have an Intel graphics processor). The graphics chip has a small bit of memory and uses some of the system's RAM to operate. The graphics card can generate a lot of heat and often will have a heat sink or fan nearby to regulate the temperature. Most computers have room on the motherboard to allow for graphics cards to be replaced or for a higher-quality card to be added. [14]


--Ksomers 00:55, 18 September 2010 (UTC)