COMPUTER FUNDAMENTALS David Samuel bhatti

Learning Objectives  Computer  ALU  CU  CPU  Computer As A System

5 Basic Operation of Computer  Input  Store  Process  Output  Control

Computer Organization

Input Unit  Gets data from the outside world and convert it into from which is easily recognized by the computer system Keyboard, mouse, joystick, scanners, digital camera, bar code reader, touch Sreeen, Speech input device (microphone)

Output Unit  Gets data from the computer system and convert it into from which is easily recognized by the user(e.g human being)  Monitor  Speaker  Printers ( different types)

Storage Unit  Types of Storage  Primary Storage Data lost as soon as the power is switched off E.g RAM  Secondary Storage Data does lost even if the power is switched off E.g Hard Disk

ALU  Arithmetic and Logic Unit  Performs Arithmetic Operation +,-,*,/  Performs Shift and Rotate Operation Shift left, shift right  Performs increment decrement operations ++, --  Performs logic operations  AND, OR, XOR, NOT

CU  Control Unit  Controls and coordinates all other components of the computer system

CPU  Central Processing Unit  CU + ALU = CPU  Brain of Computer

Computer Components  Hardware: Physical components of computer system e.g mouse, keyboard, Hard Disk etc  Software: Set of instruction which guides the hardware to do some thing useful  Firmware: Software burnt into the hardware or programs stored in ROM

Ports  Parallel Ports  Trans data 8-bits at a time  The most common interface on a computer that is intended primarily for printers and other devices.  The downloaded data eight bits at a time over eight separate lines in a parallel cable with a DB-25 female connector, part of D-Subminiature connector style.  Speed ​​ data transfer is limited to 150 Kbps (kilobits per second) and could only send a range of ten meters.  2. Serial Ports  Also called COM ports used to connect devices such as modems via a serial interface  Transmits one data bit in the order of one second.  Especially, it was a 9-pin and 25-pin male size.  The transfer speed is limited to 57KBps and a maximum cable length of 50 meters.  3. USB  It is designed to plug and play, a force that both the parallel and serial ports to a standard to be defective.

Serial vs parallel vs USB EPP is a bi-directional mode for the parallel port, while ECP = Enhanced Capabilities Port, which is similar to the EPP in that it's bi-directional, but ECP also takes advantage of DMA, meaning that anything you send through the port goes directly through memory, rather than having to go through the processor, IIRC. For ECP help go to

Buses A bus, in computing, is a set of physical connections (cables, printed circuits, etc.) which can be shared by multiple hardware components in order to communicate with one another.  Address Bus (sometimes called the memory bus): transports memory addresses which the processor wants to access in order to read or write data. It is a unidirectional bus.  Data Bus: transfers instructions coming from or going to the processor. It is a bidirectional bus.  Control Bus: (or command bus) transports orders and synchronization signals coming from the control unit and travelling to all other hardware components. It is a bidirectional bus, as it also transmits response signals from the hardware.

Key Terms  ALU  CU  CPU  Bus  Data Bus  USB  Address Bus  Port  Parallel Port  Input Unit  Output Unit  Storage Unit  Primary Storage  Secondary Storage  Main Memory  System Unit  Port  USB  Serial Port