CSC231 2010 Tiffany
- 1 PC Demolition Lab
PC Demolition Lab
- Author: Tiffany
- Class Number: CSC231
- Date: September 17, 2010
- The goal of this lab exercise was to take apart a computer and identify its components and their functions. The computer used in this lab was an old Dell PC.
- This is also known as the Central Processing Unit (CPU). It controls the execution of computer program instructions. The process of executing these instructions involves four main steps: 
- fetch: getting instruction from memory
- decode: breaking up the instruction into meaningful parts for the CPU to process
- execute: performing the appropriate operation (ex. arithmetic operation, logical operation, etc.)
- writeback: writing the results from the execute step to memory
- The most common CPUs are manufactured by Intel. In 2004, Intel introduced the Pentium 4 Prescott, which has a data width of 32 to 64 bits and operates in the range of 3.4 to 3.8 GHz. It can dissipate about 115W of power.  
- Computer memory comes in many different forms.
- The one pictured here is known as Random Access Memory (RAM). As reflected by its name, RAM allows data stored in memory to be retrieved at random, given that the row and column of the cell containing the data is known. This means that retrieval can be done in constant time. When writing to RAM, each cell can hold a single bit of data.  The typical RAM is around 2MB.
- Another form of memory is known as ROM (read-only memory). This means that the data either cannot be accessed at all or unless it is provided with an authentication key under certain circumstances. Data stored in ROM is not deleted when the computer powers down. This is known as a nonvolatile memory, as opposed to RAM, which is a volatile memory. 
- The motherboard is also known as the central printed circuit board (PCB). It is the board that houses and allows other components of the computer to connect to the microprocessor, memory, peripherals, and expansion cards. 
- The power supply unit converts 110V AC power from the wall outlet to low-voltage DC power to be used by the rest of the computer components. Most computer parts typically use 5V and 12V. The typical home-use computer has a power rating between 300W to 500W. 
- The network interface card (NIC) or simply network card is one of the PCI (peripheral component interconnect) slot cards. This card controls the interfacing of the computer to a network. The one depicted here has an Ethernet jack. The network card also houses its own ROM (read-only memory), which contains the device’s MAC (media access control) address. 
Video graphics card
- A video graphics card is another one of the PCI slot cards. It produces the images to be displayed as an output. The video graphics card has its own memory and processor, which is known as a GPU, or graphics processing unit.
- The final PCI slot card is the sound or audio card. It controls the audio signals coming in and out of the computer. The one depicted here features a line in jack, a microphone in jack, a headphone out jack, a line out jack, and a gaming controller port.
- The hard disk drive (HDD) is used for non-volatile storage of data. As the platter spins at high speeds, the read and write heads would move across the platter to modify the appropriate magnetization when writing or to look for the appropriate data when reading. The typical hard drive has around 100GB to 200GB of storage space.
Optical disc drive
- The optical disc drive (ODD) uses laser light to read from or write to optical discs. Examples of optical discs that can be read from or written to in ODDs are CD-ROMs, DVDs, etc.
Floppy disk drive
- The floppy disk drive (FDD) is used to read from or write to floppy disks. The flexible, or “floppy”, material in the floppy disk casing gets spun and the read and write head would run over the spinning disk to retrieve or record and store data on the disk much like the hard drive.
- The zip drive is used to read from or write to zip disks. Similar to a hard drive, the zip drive has a read and write head that will move across the high speed platter. Unlike a hard drive, the platter inside the zip disk is made of flexible material, which is then housed by a sturdier casing.
- Fans are used to cool down particular components of the computer. When used in conjunction with a heat sink, the fan moves air across the heat sink to cool down the component the heat sink is on top of.
- The heat sink pictured is used to cool down the CPU when used in conjunction with the fan. Since the CPU is heavily used in the computer, it can generate a lot of heat. To disperse this heat, the heat sink, which has a greater surface area, allows more heat to be transferred from the CPU to the cooling air generated by the fan.
- Ribbon cables consist of multiple conducting wires. These are used to connect internal peripherals, ie. hard drives, floppy disk players, CD players, etc., to the mother board.