3.1 Introducation to computer systems

1) TOWER: A Tower refers to a computer in which the power supply, motherboard, and mass storage devices are stacked on top of each other in a cabinet. This is in contrast to desktop models, in which these components are housed in a more compact box. The main advantage of tower models is that there are fewer space constraints, which makes installation of additional storage devices easier. A tower is made up of many different components. Each part has specific functions.

2) RAM: RAM is the part of your computer that is used as instant memory. RAM comes in many different configurations, such as DDR2 and DDR3. The type of motherboard you have will determine your RAM. RAM stores information for actively running programs so that data can be accessed and used rapidly. Contrast it to the hard drive where it has to physically write and read every bit of information, which would be far too slow to use for RAM. RAM stands for Random Access Memory. 

3) HARD DRIVE: It is the part of the computer that stores all your information. If you upload a picture to your computer, it is stored on the hard drive. Hard drive capacity is measure in gigabytes, or GB. There are typically two ways that hard drives can connect to the motherboard: SATA and IDE.  

 

4)DVD AND DVD DRIVE:  DVD and DVD drive is an optical Disc storage media format. DVD discs offer higher storage capacity than compact discs while having the same dimensions. DVD discs are used in DVD- Video consumer digital video format and in DVD-Audio consumer digital audio format, as well as for authoring AVCHD Discs. DVD discs containing other types of information may be referred to as DVD data discs. Its main uses are video and data storage.

5) ETHERNET CABLE: An Ethernet crossover cable is a type of Ethernet cable used to connect computing devices together directly where they would normally be connected via a network switch, hub or router, such as directly connecting two personal computers via their network interface controllers. When a terminal device is connected to a switch or hub, this crossover is done internally in the switch or hub. A standard straight through cable is used for this purpose where each pin of the connector on one end is connected to the corresponding pin on the other connector. One terminal device may be connected directly to another without the use of a switch or hub, but in that case the crossover must be done externally in the cable or modular crossover adapter. Since 10BASE-T and 100BASE-TX use pairs 2 and 3, these two pairs must be swapped in the cable. This is a crossover cable. A crossover cable must also be used to connect two internally crossed devices (e.g., two hubs) as the internal crossovers cancel each other out. 

6) MOTHERBOARD: The motherboard is the part of your computer that wires all of the other parts together. Every component of your computer, from the DVD burner to the CPU, will connect directly into the motherboard. Motherboard specs are typically designed around which processor (CPU). 

  

7) IDE AND SATA CABLE: 

The IDE cable connects CD drives and Hard drives to the mother board. They transfer data and commands between the devices but not power. The side of the cable with a red line indicates pin #1 and that has to be toward the correct position as indicated on the drives and Motherboard. On drives it usually connects nearest the power connector and The Serial ATA bus [SATA] is the serial version of the IDE [ATA] spec. SATA uses a 4 conductor cable with two differential pairs [Tx/Rx], plus an additional three grounds pins and a separate power connector. Data runs at 150MBps [1.5GHz] using 8GB/10GB encoding and 250mV signal swings, with a maximum bus length of 1 meter. Later SATA  enhancements move the data transfer speed to; 300MBps [3.0Gbps], and then 600MBps [6.0Gbps].

8) USB: Universal Serial Bus (USB), an external bus standard that supports data transfer rates of 12 Mbps. A single USB port can be used to connect up to 127 peripheral devices such as mice, modems, and keyboards. USB also supports plug and play installation and hot plugging.

 

9) VIDEO CARD: Video card is a graphic card, the component of your computer that interprets video signal. These cards are necessary so that you can connect a monitor to your computer. There are many types of graphic cards available: anything from high-end gaming cards to TV tuner cards. Some popular graphic card manufacturers are NVIDIA, ATI, and EVGA. The function of the video card is to generate output images to a display. Many video cards offer added functions, such as accelerated rendering of 3D scenes and 2D , graphics video capture, TV-tuner adapter, MPEG-2/MPEG-4 decoding, FireWire, light pen, TV output, or the ability to connect multiple monitors. Other modern high performance video cards are used for more graphically demanding purposes, such as PC games. 

10) PCI CARD: PCI card is a computer bus for attaching hardware devices in a computer. These devices can take either the form of an integrated circuit fitted onto the motherboard itself, called a planar device in the PCI specification, or an expansion card that fits into a slot. The PCI Local Bus is common in modern PCs, where it has displaced ISA and VESA local bus as the standard expansion bus, and it also appears in many other computer types. Despite the availability of faster interfaces such as PCI-X and PCI express, conventional PCI remains a very common interface. PCi stands for Peripheral Component Interconnect.