THE COMPONENTS OF THE SYSTEM UNIT

Peyton Farley & Katelyn Dunham

The System Unit

Motherboard- is the main circuit board of the system unit. (also called a system board)

In the motherboard there is adapter cards, processor chips in a processor slot, memory module, and an expansion slots for adapter cards.

In a motherboard electronic components usually attach to it but, other are built in.

The Control Unit

Control Unit- the component if the processor that directs and coordinated most of the operations in the computer.

In a Control Unit has a role. It initiates the appropriate action that it is programmed.

The Arithmetic Logic Unit

Arithmetic Logic Unit- another component of the processor, performs arithmetic, comparison , and other operations.

Arithmetic operation include basic calculations such as addition, subtraction, multiplication, and division.

The Arithmetic Logic Unit

Comparison operations involve comparing one data item with another to determine whether the first item greater than, equal to, or lass than the other item.

The ALU can instruct employees payment that they get. It is used for calculations.

Machine Cycle

The Machine Cycle – processor repeats a set of four basic operations.

• Step 1- Fetching• Step 2- decoding• Step 3- executing (if necessary)• Step 4- storing

Machine Cycle

Fetching- is the process of obtaining a program instructions or data item form memory.

Executing- is the process of carrying out the commands.

Storing- writing the results memory. In a computer is has to finish all of the

four steps before is goes on to anything else.

Registers

Register- A processor that contains small, high-speed storage locations. They also temporarily hold data and instructions.

There are many different types of registers that each have there own different type of storage functions.

The functions in a register our fetching, storing, and decodes it.

The System Clock

System Clock- a processor relies on a small quartz crystal circuit. (controls timing)

They have a clock speed that paces the system clock.

Each tick is a clock cycle, today they call is a superscalar.

Comparison of Personal Computer Processors

The leading processor chip manufactures for personal computers are Intel, AMD, Transmeta, IBM, and Motorola.

Manufacturers identify their processor chips by a model name or model number.

A dual-core processor is a chip that has two separate processors

A multicore processor is a chip similar to the dual-core processor.

A system on a chip is a processor that performs the functions of a processor, memory, and video card.

Heat Sinks

Processor chips generate a lot of heat which can cause the chip to burn up, so you need to use cooling.

A heat sink is a metal part with fins on its surface that absorbs heat made from a processor.

Some heat sinks are packaged as part of a processor, and some are installed at the top of the chip.

A heat sink takes up a lot of space, so therefore it needs a heat pipe.

Heat Pipes

A heat pipe is a device that cools down processors in computers.

Transfer heat without a large increase in temperature

The transfer allows them to transport heat from the heat generator.

Liquid Cooling

Computers use liquid cooling technology to decrease the temperature of a processor.

Liquid cooling technology is a process that transfers heated fluid from the processor to a grill which cools the liquid and then returns it.

Parallel Processing

Parallel processing is a process that uses multiple processors to delete a program or task.

Parallel processing separates a problem into sections so multiple processors can work on their own section at the same time.

Requires software that detects how to separate the problem and then bring it back together.

Used for applications such as weather forecasting

Special Purpose Ports

The four special-purpose ports are MIDI, SCSI, IrDA, and Bluetooth.

You must customize your computer when you purchase the order.

MIDI Port- special type of serial that connects the system unit to a musical instrument, such as an electronic keyboard.

MIDI is short for Musical Instrument Digital Interface

Special Purpose Parts

o MIDI defines how devices, such as sound cards and synthesizers.

o Synthesizer creates sound from digital instructions.

o SCSI Port- A special high-speed parallel ports.

o Allows you to attach peripherals such as disk drivers, and printers.

o SCSI is small computer system interface.

o You can daisy chain either 7 or 15 devices together.

Special Purpose Parts

IRDA Ports – Transmit data via infrared light waves.

IRDA stands for Infrared Data Association.

To make sure the light wave is in it’s path you must align the IRDA port on the device with the IRDA on the computer.

Several of these devices use a high- speed IrDA port, that is called fast infrared port.

Special Purpose Parts

Bluetooth Port- Uses radio waves to transmit data between two devices.

Do not have to be aligned with each other.

Examples: PDA’s, smarts phones, cars, and other consumers.

You can purchase a Bluthtooth wireless port adapter.

Bays

• Bay- An opening inside the system unit which you can install additional equipment.

• Drive bays hold disk drives.• Two types are external and internal.• External bays- access the drive from

outside the system.• Internal Bay- concealed within the

system unit.

Power Supply

Power supply- the component of the system unit that converts the wall outlet AC power into DC power.

Different motherboard and computers wattages on the power supply.

A fan is built into the power supply to cool all units.

New components have additional fans near processor, hard disk, and ports.

AC adapter- external power supply like, external modem, speakers, or a tape.

Expansion slot An expansion slot is a slot

on the motherboard that can hold an adapter card.

Sometimes referred as an expansion port

If you wanted to install a video card in your computer, you'd buy a video expansion card and install that card into the expansion slot.

Adds new capabilities to the computer

Come in half-size and full-size

Expansion Cards

An expansion card is a circuit board that enhances functions of a component of the system unit and provides connections to peripherals.

Adds more function to a desktop computer

Also known as an expansion board

Computers from Apple do not accept expansion cards

PC Cards Notebook and other

mobile computers have at least one PC card.

A PC is a small device that adds memory, storage, sound, fax, network, and many other things.

Because it’s so small, digital cameras use these

Developed by Personal Computer Memory Card International Association

Ports A port is the point at which a

peripheral attaches to or communicates with a system unit so it can send data to or receive information from the computer.

Devices such as the keyboard, monitor, printer, mouse, and microphone all attach to a port on the system unit.

The term jack is often referred to as an audio or video port.

The back of the system unit contains many ports.

Buses A bus allows the various devices

both inside and attached to the system unit to communicate with each other.

Bits travel on a bus Buses transfer bits from input

devices to memory, from memory to the processor, from the processor to memory, and from the memory to output or storage devices.

An expansion bus allows the processor to communicate with the peripheral attached to the adapter card.

Expansion buses are commonly found in today’s personal computers