The Components of the System Unit

By:Jacob MannsJacob Eickoff

Motherboard

• AKA mainboard, system board, planar board, or logic board.

• It is printed circuit board found in all modern computers which holds many of the crucial components of the system, such as the CPU.

Control Unit

• A control unit is a key component in all computer systems.

• It works with the central processing unit to instruct, maintain and control the flow of information.

• Without a control unit, a computer could not follow directions and might not function properly.

The Arithmetic Logic Unit

• It is a digital circuit that performs arithmetic and logical operations.

• Also called ALU.

Machine Cycle

• This is the basic operating cycle of the computer.

• It is the process in which a computer retrieves a program instruction from its memory.

Registers

• A register is a small amount of storage available as part of a CPU or other digital processor.

• It can only store words.

The System Clock• Represents a computer systems notion of the

passing time.• The system time is measured by the system

clock.

Comparison of personal computer processors

• It is important to find a personal computer with a good processor.

• Some can be good and work properly while others run badly and are more cheaply made.

Heat Sinks, Liquid Cooling, Heat Pipes

•Heat sinks- help keep electronics and computers from overheating.•Liquid Cooling- is used on computers that generate too much heat for a fan.•Heat Pipes- Hollow tubes that have a heat transfer liquid in them and when the heat reaches the end of the pipes it evaporates the air.

Parallel Processing

• Parallel processing allows computer programs to run faster because of the use of more CPUs.

Expansion Slot

• An opening in a computer where a circuit board can be inserted to add new capabilities.

• Come in two basic sizes, half and full size.

Expansion Card

• Is a printed circuit board that can be inserted into an electrical connector.

• On one edge of the expansion card holds the contacts that fit exactly into the slot.

PC Card

• Is a form factor peripheral interface designed for laptop computers.

• Originally known as a PCMICA card.

Ports

• A port serves as an interface between other computers or peripheral devices.

• Specialized outlet on a piece of equipment to which a plug or cable connects.

Special Purpose PortsFive different types of these ports.

• MIDI- musical instrument digital interface• SCSI- small computer system interface• USB- universal serial bus• 1394 port• IrDa- infrared data association

Buses

• A set of physical connections which can be shared with multiple hardware components in order to communicate with one another.

Types of Expansion Buses

• General - Connects the expansion slot to the chip.

• Standard – Has faster speed than general.

Bays

• Space inside the computer for DVD, CD, and floppy disk.

• Place where external components connect to the computer.

Power Supply

• Converts and maintains AC to lower voltage DC power for internal components of a computer.

• Modern personal computers use a switch mod power supply.