1. Computer Hardware
The Processing Unit

2. Communication Devices
The Computer System
Communication Devices
Processing Unit
Input Devices
Output Devices
Storage Devices

3. The Processing Unit
The main part of a microcomputer is called the System Unit
Most of the processing hardware is on the motherboard

4. The Processing Unit
The motherboard is the main circuit board in a computer
A circuit board is a sheet of fiberglass on which electronic components are soldered
These components are connected with traces of copper printed on the surface

5. Motherboard Components
The Motherboard
1 – The CPU
2 – The Chipset
3 – Main Memory
4 – The System Bus
5 – The System Clock
Five Main
Motherboard Components

6. The CPU ALU Registers CPU The Central Processing Unit has 3 parts
Control Unit
ALU
Registers

7. The Control Unit The Control Unit Regulates the flow of information
Monitors all operations performed by the system
Runs Programs:
Fetches program instructions from memory
Increments the Program Counter
Decodes the instruction
Executes the instruction
Writes results to memory

8. The ALU The Arithmetic and Logic Unit
Performs all calculations (+, - ,*, /)
Returns the result of simple logic decisions ( is x > y true or false?)
Calculations can be accelerated by a Floating Point Unit (FPU)

9. Registers Registers A small amount of high-speed memory on the CPU
Registers hold the current program instruction and data
Very fast but also expensive

10. The Chipset
A chipset is a group of ICs (Integrated Circuits or computer chips) that are designed to support the CPU.
On most PC motherboards the chipset has two microprocessors often called the Northbridge and the Southbridge.

11. The Chipset
The Northbridge chip links the CPU to high-speed components like main memory and video controllers.

12. The Chipset
The Southbridge chip then links to lower-speed peripheral devices through connections like PCI or PCI-Express.
The Southbridge may also have built-in Ethernet (networking), USB or audio device support

13. The System Bus
In computers, a bus is a set of connections (wires) that is shared by multiple hardware components in order to communicate.
Bus
A general term for the bus on a motherboard that connects the CPU to all the other components. Also called a local bus.
System Bus

14. The System Bus
The main bus between the CPU and main memory typically through the Northbridge.
Frontside Bus
A common type of local bus that is used to connect the Southbridge chip to peripheral devices such as network expansion cards.
PCI Bus

15. Main Memory-1
Inside the CPU is a small amount of high-speed, expensive computer memory called registers.
The registers are used for storing data currently being processed in the CPU
CPU
Registers

16. Main Memory-2 Most data is stored in Main Memory.
There are two types of Main Memory: RAM & ROM
Main Memory
Ram
Rom
CPU
Registers

17. Main Memory-3
Between Main Memory and the CPU is a buffer or temporary storage called cache (pronounced like cash)
Cache memory stores data so that future requests for that data from the CPU can be served faster.
Main Memory
Ram
Rom
Cache L1 L2
CPU
Registers

18. Main Memory-4

19. The System Clock
On the motherboard is a component that generates a clock signal
This is a timing signal that synchronizes all data transfer in a computer system.
The CPU also executes instructions at a speed set by the clock signal

20. The System Clock Clock rates are measured in hertz (cycles per second)
Household AC current alternates at 60 Hertz
1 megahertz (MHz) = 1 million hertz
1 gigahertz (GHz) = 1 billion hertz
German physicist Heinrich Hertz made important scientific contributions to the study of electromagnetism.

21. The Motherboard Ports CPU Expansion Slots Northbridge Southbridge RAM
ROM (BIOS)

22. A Motherboard