System Unit Devices
The Processor (CPU) is to control the activities of the computer system.
Intel - Intel makes the Pentium and Centrino ranges of processors.
AMD - AMD makes the Athlon and Turion ranges of processors.
Random Access Memory (RAM): Data and programs currently in use are held in RAM.
The Motherboard: it is the main circuit board for the computer system.
Graphic card: has to decide what to do with each one of these pixels in order to create the required image.
Sound card: for good quality sound
Network card: This can simply be a home computer connected to a Broadband connection or a number of computers connected together to share resources. Modem: A modem is necessary to access the internet using a standard telephone line.
Hard disk drive: when the computer is switched off, the contents of primary storage are erased. A system was needed whereby work could be saved for use at a later time.
Hard disk drives can be internal or external in type.
IDE The disks connect to the motherboard using a ribbon cable.
SATA The cables are much smaller and allow better air circulation in the system unit.
External hard disk drives as IDE or SATA
Optical drives
Optical drives use laser technology to sense pits and lands mechanically pressed into a polycarbonate disk.
Disk capacity 4.7GB 8.5GB 9.4GB 17GB
1 .DVD-ROM Digital versatile disks are read only.
2 .DVD-R They can be written to only once.
3 .DVD-RW written several times.
4 .DVD+R They can be written to only once.
5 .DVD+RW written several times.
6. HD-DVD can hold 15GB of data or more.
7.Blu-Ray hold 25GB of data. A dual layer disk can hold 50GB.a double sided and double layered disk can hold 100GB of data.
8.CD RW