103b az 2012
Lab Report CS103
This is a lab report for CS103: http://cs.smith.edu/dftwiki/index.php/CSC103_2012
The list of all lab reports can be found at: http://cs.smith.edu/classwiki/index.php/CSC103_Page_2012
The computer we took apart was a Dell Optiplex GX270.
The processor is next to the RAM slots on the motherboard. This processor is an Intel Pentium 4 and runs at 2.8GHz. The processor is located under a large heat sync that is required so the large number of instructions the processor completes do not make it overheat.
The processor carries out instructions entered into the computer by performing basic operations. They are "analogous to the brain in the computer" according to Wikipedia
"Two typical components of a CPU are the arithmetic logic unit (ALU), which performs arithmetic and logical operations, and the control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary."
Random Access Memory(RAM)
The RAM is located on the motherboard, near the processor. This computer has two RAM chips, 256MB each for a total of 512MB.
Random Access Memory is short term memory, as opposed to the long term memory of the hard drive. When the computer is turned off the data in the RAM is lost. This type of memory is useful when a program or file has been loaded once and needs to be loaded again. Without RAM, they would have to be loaded from the hard drive again which takes longer.
There are two forms of RAM
- static RAM (SRAM)
- dynamic RAM (DRAM)
" In static RAM, a bit of data is stored using the state of a flip-flop. This form of RAM is more expensive to produce, but is generally faster. DRAM stores a bit of data using a transistor and capacitor pair, which together comprise a memory cell. " 
The CD/DVD player is located on the top of the machine, near the zip drive and the hard drive. It is a combination CD/DVD drive.
This is one form of input into the computer. It can be used to load data from CDs for music and programs as well as movies from DVDs. Although many things can be downloaded these days, CDs and DVDs are still a popular way to load information into computers.
The power supply is located in the corner of the machine, next to the motherboard and the hard drive. It can output a maximum of 210W.
The power supply "converts mains AC to low-voltage regulated DC power for the internal components of the computer."  Without the power supply the computer would not be able to supply electricity to the individual parts, which only run on DC current.
The cables in the computer are for transmitting power and data between the components of the computer.
The hard disk is on the top of the computer, next to the CD/DVD and zip drives. This harddrive holds 40GB of data. Inside the case of the harddrive is the disk the data is stored on and the read/write head.
When data is required for the computer, the read/write head moves over the disk in the hard drive and the information is transmitted. The hard disk is made up of " rapidly rotating discs coated with magnetic material and with magnetic heads arranged to write data to the surfaces and read it from them."  "Introduced by IBM in 1956, hard disk drives have decreased in cost and physical size over the years while dramatically increasing in capacity and speed."
The motherboard is located next to the power supply underneath the RAM and the processor, among other things. The lines on the motherboard are wires that connect the various parts located on the motherboard.
The motherboard is the "central printed circuit board (PCB)". It connects the vital parts of the computer through wires and sockets. The CPU and RAM, among other things, are connected to other important parts of the computer via the wires embedded in the motherboard. Components such as RAM, also called daughter boards, can be connected to the motherboard via slots. Other daughter boards, such as graphics and video cards, can also be connected to enhance the performance of other parts of the computer.
Examples of potential daughter boards include:
- video cards
- sound cards
The crystal is located next to the RAM and the processor. It oscillates at a certain frequency and regulates how fast the processor runs.
The battery keeps the clock running when there is no power to the computer. Without this the clock would not be correct when the computer is turned back on.