1. The Computer Systems

2. Computer System CPU Is the brain of the PC. All program instructions are run through the CPU Control Unit This decodes and executes the program. ALU This performs all mathematical and comparision instructions.

3. Main Memory Stores the program that is being decoded by the CPU. RAM = volatile ROM = permanent Backing Store Hard Disk, USB Disk, etc. Stores programs permanently. Input Keyboard, Data Reader, etc. Output Screen, Printer, etc.

4. Buses Control Bus Carries control Signals to read or to write Data Bus Carries Data between Processor & Memory Address Bus Carries the address (location) of data or program instruction. Carries the address of input or output port.

5. Motherboard

8. Processor The primary chip of the system that oversees all the other components of the system Types of Processor 1 st Generation8086 3 rd Generation80386 called 386 32bit computing 6 th GenerationPentium II64 bit computing Celeron II Duron128 bit computing 8 th GenerationIntel Core256 bit computing

9. Components BIOS Basic Input/Output System. support data transfers between the various components. RAM Stores the programs, and data temporarily while the CPU runs the program. When the computer is turned off the contents are lost. ROM Stores programs/data but does not allow updates. Its contents nonvolatile –are not lost when the computer is switched off.

10. HARD DISK A magnetic disk can store upto 100 gigabytes. IDE - Integrated Drive Electronics Disk devices connect to the PC through an (IDE) interface. IDE uses a special configuration called master and slave.

11. Ports A port is a connection or plug in on the PC. USB -Universal Serial Bus An standard that supports data transfer rates of 12 Mbps Serial Transfer of data one bit at a time. Parrallel Transfer of data several bits at a time. (faster than serial) Firewire A very fast external bus that supports data transfer rates of up to 400 Mbps

12. Typical PC System