Chapter 4 : System Unit Component

System unit :

·        

     The motherboard is the main circuit board of the system unit :

·        A computer chip contains integrated circuits

Processor- Central Processing Unit (CPU) interprets and carries out the basic                                                                              instructions  that operate a computer

·        Have a control unit and an arithmetic logic unit (ALU)

        Multi-core processor --->Dual- core processor--->Quad-core processor

·        The  arithmetic logic unit (ALU) performs arithmetic, comparison, and other operations

·        The system clock controls the timing of all computer operations

·        The pace of the system clock is called the clock speed, and is measured in gigahertz (Ghz)

·        A processor chip generates heat that could cause the chip to burn up, it require additional cooling : Heat sinks, Liquid cooling technology

Data Representation :

·        Analog signals are continuos and vary in strength and quality

·       

     Digital signals are in one of two states : on or off

·        

     The binary system uses two unique digits ( 0 and 1 ) : Bits and bytes

Memory :

·        Consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions and the results of processing the data

·       

     Store 3 basic categories of items :

ü 

      -The operating system and other system software

ü         -- Application programs

ü          --Data being processed and the resulting information

·        Memory size is measured in kilobytes ( KB or K ), megabytes (MB), gigabytes (GB), or terabytes (TB)

·        

     2 types or memory :

Volatile memory : Loses its content when power is turned off, Example (RAM)

Nonvolatile memory : Does not lose contents when power is turned off,  

                                    examples include ROM, flash memory and CMOS.

·        

     RAM chips usually reside on a memory module and are inserted into memory slots

·       

     Memory cache speeds the processes of the computer because it stores frequently used instructions and data

·       

     Flash memory can be erased electronically and rewritten : - CMOS technology provides high speeds and consumes little power

·       

•      Access time is the amount of time it takes the processor to read from memory : Measured in nanoseconds

Bays :

·        A bay is an opening inside the system unit in which you can install additional equipment

-A drive bay typically holds disk drives

The power supply converts the wall outlet AC power into DC power.