… but what parts does it have and how do they work?

A computer looks like this...

Expanded view of a PC (Personal Computer):

1. Monitor2. Mother board3. Processor4. IDE ports5. Principal memory (RAM,

random access memory)6. Expansion boards7. Power supply8. Optic storage decive (DVD)9. Hard disk / hard drive10. Keyboard11. Mouse

A first approach to computer's hardware

A first approach to how it works

Everytime that there is an input of information, the computer stores it in the RAM (memory), then the processor or CPU interprets the information and then outputs the information.

For instance, when someone clicks on the Save icon in a word processor program (like Word or Writer):

1. The information is saved in the memory (the information stored would be something like “someone clicked on the save icon with the mouse”, but expressed with 0 and 1's).

2. The processor/CPU interprets that in this program that information means “to save to the hard drive the document that the user is working with, which is in the memory/RAM)”.

3. The processor/CPU orders the memory/RAM to release the document.4. The processor/CPU orders the hard disk to store the document that has been released by

the memory/RAM.

CPU

Chipset

Main memory

Input devices - mouse- keyboard

Output devices - monitor- printer

Permanent storagedevices - hard drive- DVD- Pen drive

To understand a little better how it works1.- The information is transmitted between the different parts in the computer through some special types of wires that are called buses. The information is first coded in bits (1’s and 0’s), that are transmitted using electrical pulses (for instance, a 0 could be equivalent to have 0 volts during a period of time and a 1 equivalent to have 5 volts during that period)

2.- Peripherals and permanent storage devices put information in and out of the computer

3.- The chipset controls the peripherals: it detects when information enters the computer, decides which of the peripherals can put an information in the buses each time, etc.

4.- The main memory (or RAM or memory) stores:a.- the program that is being usedb.- the document that is being usedc.- the information that comes from or goes to the peripheralsIt is temporary, so its content is lost every time we turn the computer off

5.- The processor (or CPU):a.- interprets the instructionsb.- does the operationsc.- sends the appropriate orders to the rest of the elements in the computer.

Mother board 2.93 Ghz Celeron D340 (year 2000 aprox): The internal components are

inserted in slots and sockets.Peripherals are connected to the

ports.

1. Socket for the CPU2. Slots for the main memory/

RAM3. IDE connectors for some

storage devices (hard drive, DVD…)

4. AGP slot for graphics card5. PCI slot for some expansion

cards: network, sound…6. Ports for some external

peripherals such as the monitor and the printer…

7. USB ports for some external peripherals and storage devices such as the mouse, pen drive, printer…

In the mother board all the components are interconnected

The battery is used to keep time and date in the computer

Ports can be serial (it is transmitted one bit after the other) or parallel (various bits are transmitted simultaneously). The most popular port these days is the USB (Universal Serial Bus)

The BIOS stores permanently the most important information so the computer can start working. Everytime the computer is turned on, the processor goes to the BIOS to know the hardware that is connected and where to find the operating system (where in the hard drive), so it can be sent to the main memory.

In the mother board all the components are interconnected

Locate the most important elements and explain what they are for

1. CPU socket2. Slots for the main memory/

RAM3. IDE connectors4. AGP slot5. PCI slots6. Ports for some external

peripherals such the monitor and the printer…

7. USB ports8. BIOS9. Battery10. Chipset11. Power connector

Make sure you are able to:• Explain how a computer works• Recognize and locate the most important elements in the previous motherboard pictures• Explain what each of the elements in a PC are used for (buses, peripherals, storage devices,

main memory, processor, chipset, ports, slots, sockets, PCI and AGP cards, IDE ports, BIOS)

Extra activities:1. Google “motherboard” to see more pictures of different models of mother boards and try to locate

the most important elements.CPU socket.2. Visit http://en.kioskea.net/contents/377-motherboard to solve any doubt about the

hardware connected to the motherboard