Physical Identification

C. P. U.

Let us go through the physical identification of each part of a computer system.

MOTHER BOARD is one important part of computer system, which executes the whole task of the operator.

As you can easily understand that Mother board consist of CPU, RAM, ROM, FDD, HDD, CD-ROM, installed in a metallic box or mainframe called chassis, which can be in the form of Tower.

Front view.

As you can clearly observe that in a standard CPU box there are:

Storage bays to insert the Hard Disk Drive, Floppy Disk Drive, CDROM, which are external memory of the computer to store the information.

Power on/off switch provides power supply to the computer.

Power on indicator to indicate the power status of the computer.

HDD indicator light: When it blinks that mean system is approaching (accessing) HDD to execute task like read, write, save etc.

LAN LED indicator: If system has internal Modem.

Let us go to the rear view of mother board.

It is clear that CPU box is a master to execute all tasks either give display or print information or enjoy music or see movie.

To execute the entire task it obviously requires accessories attached to the Motherboard at the rear (back) side of Motherboard i.e.

Monitor to see the edit information.

Speakers like Sound blaster to hear music.

Printer to print information.

Joystick to play games in computer.

Keyboard to feed information.

Amplifier to amplify the music signal.

CD player to give music.

Facilitation the connection of devices with motherboard, chassis of motherboard equipped with various PORTS just like socket of electricity to get power.

So, to understand interconnectivity of Motherboard with accessories, we should understand the application of each port & connector.

Ports are designed "D" shaped, so term D-port often use to name them.

If the message is given through one wire they called serial port, if message given using more than one wire the port called parallel port.

Parallel ports are faster than serial port. Serial ports are significant, where the speed of transfer of message does not play an important roll for example mouse & keyboard port.

PS/2 or D-Port for mouse & Keyboard.

These are D-type 9 or 25 pin ports called COM ports and round ports called PS/2 ports.

9 pin ports are specified for connecting mouse & keyboard. While 25 pin connectors are for connecting MODEM.

Some chassis are equipped with PS/2 port, which is circular port & work in the same principle. To get connection we have to bus PS/2 keyboard & mouse.

D-Port for printer (LPT1).

There are two row 25 pin ( 13 +12) female ports specified for printer cable.

D-Port for display.

There is 3-row 15 (5+5+5) pin female port for connecting signal cable of display monitor Other then above there are two D- sub three pin connector to give power supply to CPU box as well as monitor.

If your computer is equipped with MULTIMEDIA i.e. if your computer works as a music CD-player to enjoy music or VCD player to see movie, then four additional ports attached to motherboard.

Line in port to get sound signal from cassette player, CD-player etc.

Line out port to get sound signal to be amplified connected to amplifier. Sound port to connect two speakers.

2- row of 15 pins (8+7) D-type joystick port to connect joystick for playing.