103a-ah PC Lab

From CSclasswiki
Jump to: navigation, search

Introduction to the computer parts


Also known as a central processing unit is a small chip within the computer that functions as the computer’s brain by processing instructions. It is made up of millions of small transistors. One major brand of processor manufacturers is the Intel. The Intel’s single core x86 microprocessor is known as the Pentium. Processors vary in internal clock speed. Depending on the megahertz, the larger the frequency the more cycles per second the processor is able to carry out and therefore the faster it is.


The computer’s memory is also known as its RAM or Random Access Memory. RAM is either measured in megabytes or (nowadays) gigabytes. So a 1 Gigabyte stick of RAM has about 1 billion bytes of memory that programs can use. The more RAM you have the fewer amounts of times your CPU must read data from your hard disk. RAM is dependent on the type of operating system and the motherboard of a computer. For example a 32-bit operating System will most likely not be able to support 8 Gigs of RAM.


A DVD-ROM supports disks with capacities from 4.7 Gigs to 17 Gigs of space. A CD-ROM is an optical disk known as a Compact Disc, read-only memory and is designed to store data in the form of text, graphics, or even stereo sound. A CD is made up of tiny bumps or pits arranged in a spiral-like way on one of its faces. It is read with a laser from a DVD/CD drive. When the laser passes over the bumps, the light gets reflected off of it and the distance between these reflections is measured and the information is encoded. Each pit is represented as one bit.

Hard Drive:

Also known as a hard disk, is a non-volatile data storage device. Hard drives nowadays range in the Gigabytes of storage. Data stored in the hard drive is accessed instantaneously; the read-write head hovers above the disk’s magnetic surface at about 170 miles per hour. The magnetic surface of the hard platters in a hard drive is formatted into tracks or circles which can hold a fixed number of bytes. What data is recorded, the hard disk platters rotate at high speeds where the head produces a magnetic field and magnetizes the region of data to be stored. The surface acquires a magnetic patter representative of the information being stored.

Power Supply:

A power supply supplies power throughout the computer and converts lethal 110-115 or 220-230 volt AC current into a low-voltage DC current that is usable for the computer. The power supply connector contains 4 main wires. The first pin is a yellow wire which signals out +12 Volts of current and the fourth, red wire signals +5 Volts of current. These are typical voltages supplied for the computer. The +5 volt is generally used for digital circuits while the +12 volt is used to run motors in disk drives and fans.


There are many types of computer cables, most of which are internal ones (ATA, STAT, CD DVD Hard Drives, I/O and power, etc). They are necessary for sending and retrieving bits of information from one part of the computer to the other.


A central or primary circuit board that provides the electrical connections to communicate with other components within the system. These connections are wires and one connection is called a front side bus, usually a 32-bit wire (or sometimes 64-bit) that carries data between the CPU and the Northbridge. The motherboard also contains slots for RAM.


Usually found on the motherboard in some sort of holder (for easy replacement). This battery is used to power a chip called the Real Time Clock (RTC) chip. This chip is a quartz watch that runs all the time regardless of whether the computer is on or not and is used to keep track of real time and date.


A small quartz that acts as an external clock unit for keep track of the time and date. The crystal spins generating a clock signal at a certain megahertz to keep track of this time.

Title: Open It Up! Lab

Name: Christine Grascia

Date: September 22, 2008

Model Number: Dell Optiplex GX280

Partner: Talia Brooke





The main objective of this lab was to introduce and familiarize one with the internal components of a modern computer. The lab was set up to understand the individual parts of a computer by taking it apart ourselves.


Usually computers open by easily popping off one side of the tower. However this model opened in a box-like manner.

We Initially started by unhinging the plastic coated wires off of the motherboard (a large, green, thin, and square circuit board). We had to unscrew a couple of bolts from either end of the motherboard. First removed were two small rectangular green circuit boards known as the RAM. Each ram was 512 megabytes of memory.


Next we removed the power supply - a large box containing a fan and many plastic coated wires.


Once we got that out of the way we were able to free up the motherboard from the tower's case. On the motherboard we removed the heat sink (A difficult task at first) and found the processing chip glued on underneath it. Interestingly, this special glue prevents the processing chip from over heating.


The motherboard contains a common silver colored battery. Its use is mainly saving information such as the date and time.



Next we removed both the hard drive and the CD drive. Both components look very similar. Our 80 Gig hard drive (I thought it would be more for a tower...but even over a short range of 2 or so years the hard drives have greatly increased in size) is what stores the computers' programs and OS. The CD drive is also a built in I/O device, much like the hard drive.



Other, less important things that we removed from the tower was a USB chip containing a USB port and a sound port. These ports were connected directly to the motherboard.