Computer Fundamentals

Fundamental Computer Concepts Storage

The fundamental concepts of computing starts with the theory of “signaling” which persists in both human brains and Computers , the basic difference of signalling in between computer and human brain is the switches and neurons . The switches in computers works on “ON/OFF” based on “binary” systems whereas neurons also works on “ON/OFF” based on “performing or not for an action” .

Read the following chapters or download  in PDF computer-concepts



Before start thinking about computing concepts, let’s consider our brain, the brain uses chemicals to transmit information with high speed electrical signals (primary afferent axons) in the nervous system. Just like our brain, the computer uses electricity for signals to transmit information, the good thing is our brain works fast as compare to the wires in a computer.

The signalling theory is based on “ON” and “OFF” with both human brain and Computer, the computer uses switches that are either on or off (“binary”) whereas neurons in our brain are goes on “ON” or “OFF” condition by either clicking for an action or not clicking for an action.

The ON/OFF difference in between computer and human brain is the neurons. Neurons are more than just ON or OFF, because of the “excitability (the behaviour of simultaneously changing)”.

A neuron is always changing because neuron is continuously getting information from other cells through synaptic contacts. Like cells in human brain, Computer memory grows by adding computer chips , our brain’s memory grows by stronger synaptic connections. Similarly the brain has requirement of oxygen and sugar for power; the computer needs electricity for power.

The Computer is basically an analytical engine, which can perform

  1. A program,
  2. Can carry out calculation
  3. Can make decisions based on carryout calculation

Characteristics of computer

There are four primary distinguishing characteristics of computers are:

  1. Fast
  2. Efficient
  3. Storage
  4. scalability

Brief history of Computer

The first computing device was invented by Abacus in 2400 BC. It’s an Ancient device to record numeric values.

The first digital computer was developed in 1944 by Harvard Mark I in 1944 . it was the First fully automatic digital computer to be completed , it was :

  • 51 feet wide, 8 feet high, 2 feet deep
  • Built with switches, relays, and rotating mechanical shafts/clutches
  • Storage for 72 numbers, each with 23 decimal digits in length
  • It could Read instructions from paper tape, one at a time

The first microprocessor was the Intel 4004, introduced in 1971. Although it was not very powerful, but it was primarily used to perform simple mathematical operations in a calculator called “Busicom.”

The computers entered in our home in 1974 after the making of Intel 8080 , that was the complete 8-Bit computer

Just like microwaves or telephones, devices with tiny sensors which works as a microprocessor, are now-a-days becomes integrated with our daily lives to make IoT concepts easier than ever, with the connecting people technologies, we cannot imagine a life without computing devices.

The predictions are , by 2049 , a $1000 computer will exceed the computational capabilities of the human race.

Generation of Computers

First Generation Hardware (1951-1959)

The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.( Source – United States Census Bureau )

Second Generation Hardware (1959-1965)

Vacuum tubes were replaced by transistors in the second generation of computers.

Third Generation Hardware (1965-1971)

The IC (integrated circuit) Silicon Chip was the hallmark of the third generation of computers. Semiconductor used in Silicon chips and replaced the Transistors

Fourth Generation Hardware (1971-Present)

The microprocessor came in the fourth generation; thousands of integrated circuits were used in a single silicon chip

Fifth Generation Hardware (Present -)

Talking about Fifth generation computing devices is beyond, as it is still in development based on artificial intelligence, although we are now-a-days using some fifth generation computing applications, such as voice recognition.

The fifth generation will imply a conceptual theory of parallel processing and superconductors to make artificial intelligence into a reality. Similarly, Quantum computation, molecular and nanotechnology will radically change the computer concepts in near future.

Classification of computer

We can classify the computers by size, functionality and data handling. In relation to size, the categorisation can be:

  1. Mainframe computers – mainly Designed for huge businesses, banks, universities
  2. Minicomputers-Designed for medium and small scale organizations (Industrial process control, data collection, small business applications
  3. Micro-computers- using in our home as desktop, laptop, ipad etc.
  4. Super computers- used for quantum mechanics, weather forecasting, climate research, oil and gas exploration and molecular modeling.


A CPU can be defined as the administrator or brain of the computer, which is not only executes the instructions but also controls all the storage mediums (primary or secondary), it controls and coordinates the Input -Output activities as well as the different functions of other attached devices. Most of the calculations take place here.

Data vs. Information

Data – by definition it is a collection of raw and unprocessed facts such as charts , reports, inventory ,  scores, names, addresses, diagrams or drawings and maps.  Data may be numerical or non-numerical.

Information – it is the “data” that has already been manipulated and transformed into something useful or meaningful information a result of processing of input of raw data through a computer’s processing mechanism.

Information Processing Cycle

When we talk about Concept of Computer Operation or CPU operations, it can be described with the following diagram; The Four Basic Functions of a Computer

  1. Input is the function of a computer where the data is placed inside or entered into through input devices such as keyboard , mouse , cameras , microphone etc. , whereas data can be in the form of voice , video , alphabetical , alphanumeric or special character .Input is a  procedure of feeding data into a computer .
  2. Process or information processing cycle is the function(s) where a program or group of programs behave on the data; it take place mainly inside the computer’s CPU (Central Processing Unit or through microprocessor. Process is basically the operation of manipulating and transforming data into something useful or meaning full information.
  3. Output is the function of a computer where the transformed data through information processing cycle is shown to the user for consumption. Output is basically the result of the microprocessor processing function
  4. Memory is a temporary storage; it is basically a warehouse of computer system because it holds the information for information processing cycle. It holds the data for any meaningful result. RAM is not a persistent storage as it does not continuing to hold the data over a prolonged period.

In the above mention diagram, the fetch-decode and execute-store cycle is basically the information processing cycle execute by the CPU components, we can define the cycles are as Machine Cycle, with its sub cycles as instruction cycle and execute cycle.

  • Machine Cycle– Every time the CPU executes an instruction, it takes a series of steps. The complete series of steps is called a machine cycle. A machine cycle can be divided into two smaller cycles. These are instruction cycle and execution cycle.
  • Instruction cycle: instruction cycle of CPU includes two steps
  1. Fetching: Before execution of an instruction, the control unit (CU) must retrieve or fetch data from the computer’s memory.
    2. Decoding: similarly, before execution, the control unit (CU) must decode the command into instruction set.
  • Execution cycle: execution cycle CPU also includes two steps
  1. Executing: in execution, the instructions converted into machine code by the CPU.
    2. Storing: The CPU stores the result of an instruction in memory.

What is a Microprocessor?

 The microprocessor, also known as the Central Processing Unit (CPU) can be termed as the brain of all computers. Similarly, multiple microprocessors, if works together, are the “hearts” of datacenters, super-computers, communications products, and other digital devices.

It’s very difficult to analyze that only 60-65 years before, computer was rare and was not available for public use. Thanks to the microprocessor, in ’80s computers entered into our homes which made a great impact on our lives.

Today, latest microprocessors such as Intel core i7 , can perform extremely sophisticated operations in various fields of our daily life such as meteorology, aviation, nuclear physics and engineering . the latest microprocessor takes much less space and delivers much more performance.

in the last 40 years of microprocessors developments , microprocessors  becomes faster and more powerful with increasingly smaller in size and much more affordable.

The manufacturing of a microprocessor is extremely complex and demanding process which involves multiple hundreds of steps in “cleanrooms.” Cleanrooms or manufacturing plants, contain air which is 1,000 times cleaner than a hospital’s operation theater. The building of one plant costs approximately $5bn.

What microprocessor consists of ?

Microprocessor Consists of CU , ALU and MU . a CU does not involve in any process , but it coordinates and control the operations of every individual unit of the CPU, Just  like a traffic police man who controls the traffic and directs it accordingly.

CU executes and control the instructions & directs the input devices, informs ALU for processing, coordinate to arrange temporary or permanent memory locations and prepare the output devices for results.

ALU responsible to perform all arithmetic operations and logical operations. Arithmetic operations such as addition, subtraction, multiplication, division. whereas logical operations are the comparison of two values. On the result of comparison further actions are taken upon data. Comparison examples are =, < and >. Because of two operations of ALU we can illustrate ALU as Arithmetic/Logic Unit.

What is Microprocessor execution process?

A execution is a process of the instruction cycle as mentioned above the fetch–decode–execute cycle, is the basic operational process of a computer. The cycle repeats continuously by CPU, from boot-up to shut down. A microprocessor executes a collection of machine instructions, based on the instructions, a microprocessor perform following three tasks:

  • Using ALU to perform all arithmetic, logic and comparison operations.
  • The second task is, the microprocessor can move data from one memory location to another.
  • The third task is, the microprocessor can make decisions and jump for a new set of instructions based on those decisions.

Modern microprocessors contain complete floating point processors that can perform a comprehensive and sophisticated mathematical operations based on large floating point numbers

What is the Microprocessor working mechanism?

To communicate with external world, Microprocessor uses bus .A bus is a collection of separate wires which work together to perform a particular task, the bus is used to pass information between modules. A microprocessor works with the following type of busses:

  • Address Bus -It is a group of wires or lines for the transfer of the addresses of Memory or I/O devices , addresses may be 8, 16 or 32 bits wide to send an address to memory – a 16 bit address means it can address 65,536 different memory locations.
  • data bus- As mentioned in name, it is used to transfer data within the Microprocessor and Memory .it may be 8, 16 or 32 bits wide to send data towards memory or receive data from the memory
  • Control Bus– it is used to process data, i.e. decision take place here that what to do with the selected memory location. the bus uses RD(read) and WR (write) lines to inform the memory whether it wants to set or get the addressed location. four control bus connections ;
  1. Memory read control- MRDC
  2. Memory write control-MWTC
  3. I/O read control-IORC
  4. I/O write control-IOWC

Control Bus Mechanism

Different types of processors, including AMD and Intel, uses following two more bus along with the above mention three basic busses :

  • clock line uses for a clock pulse for sequence the processor, to execute the processor instructions.
  • reset line that resets the program counter to zero (or whatever) and restarts execution

How microprocessor bus / lines works?

Busses (address/data) and lines (read/write) connect either to RAM or ROM

EXAMPLE – if microprocessor has address bus 8 bits wide and a data bus 8 bits wide. That means that the microprocessor can address (28) 256 bytes of memory, and it can read or write 8 bits of the memory at a time.

8 Bit wide Work example:

01101010 = 0•27 + 1•26 + 1•25 + 0•24 + 1•23 + 0•22 + 1•21 + 0•20 = 64+32+8+2 = 106=j

Let’s assume that this simple microprocessor has 128 bytes of ROM starting at address 0 and 128 bytes of RAM starting at address 128.

What are basic types of Microprocessor?

RISC Based – Reduced instruction set Computer

it can run multiple instructions at a time , it is a system that uses a small but highly optimized set of instructions, these type of microprocessor used for specific tasks , for example Sun SPARC systems is often uses RISC based processor .

CISC Based – Complex instruction set computer

In this type of processor, single instructions can execute, for example Intel x86 are CISC based processors. It runs normal CPU low-level operations such as memory loading, an arithmetic operation, and a memory storing.

What is Assembly language?

In order to understand completely how a microprocessor works, it cannot be done without knowing inside and learn about the logic used. the logic is about the assembly language – the native language of a microprocessor – this is also called as  ‘machine language instructions’ , as it process set of instructions with the help of 1’s and 0’s strings .

It is a low-level language to program a device. But as machine language is too obscure and complex for using in software development, we use assembly language for a specific family of processors that represents various instructions in symbolic code.

when we work with any application or utility ( such as game or utility, for example antivirus utility  ) , it concerts into assembly language in form of 1 and 0 with the help of assembler ( such as object oriented programming Syntax , for example .net object oriented syntax ) .


A chip is an integrated circuit (IC) or integration of transistor circuits. CHIP uses on PCB, after the invention of 2nd generation of computers where transistor replaced by vacuum tubes, since then transistors playing a important role in computing techniques. Now we uses millions of interconnected transistors or diodes in a CHIP.

Normally CHIP is small with thin piece of silicon used in it .It might be large than a inch on a side and can contain tens of millions of transistors. Simple processors consist of a few thousand transistors.

CHIP, which we called as Integrated circuits can be classified into analog, digital and mixed signal (i.e. both analog and digital on the same chip).Digital integrated circuits can contain from one to millions of logic gates, flip-flops and multiplexers in a few square millimetres. Today, the small size of these circuits allows high speed with low power consumption and reduced manufacturing cost to integrate with motherboard or PCB.

A chipset is the component which defines routes for data in between the computer’s busses.


Look at your heart; it is a junction of our nerves to make our body able to work. Motherboard is the heart of computer as it provides a junction where all the internal components of the PC can connect through ports and cables. It is the biggest printed circuit board for CPU which covers most of the bottom of the system unit,

Just a decade before we have a circuit board with serial and parallel connections for a light up of a LED; now-a-days we have now printed circuit boards (PCB) with serial and parallel buses for data management. A bus is the path through which a device sends its data so that it can communicate with microprocessor and other devices.

 An anatomy of Motherboard can be illustrated as:

We can bifurcate busses into following categories:

  • Data width-used to determine the bandwidth
  • Cycle rate-used to determine the bandwidth

For example An 8-bit bus which will be 1-byte data width operates at a cycle rate of 1,000 MHz (1,000,000 times per second) , it can transfer 8 Mbps (1 Mbps).

  • Device management is a category which uses above mentioned two types of busses i.e. serial and parallel. We can define serial communication as it is the process of sending data in a line, one bit at a time. Parallel communication bus is the bus for several bits sent at a time, as a whole, on a link with several parallel channels.
  • Memory busses– It is the interface between the RAM and the motherboard
  • Front Side Bus (FSB) – The Front Side Bus is the interface between the CPU and the motherboard, specifically the North Bridge/Memory Controller Hub.
  • AGP Bus – AGP/Pro (Advanced Graphics Port) is the interface based on 32-bit PCI standard system
  • EIDE Bus (Enhanced Integrated Drive Electronics) – used for IDE hard drives include a device controller mounted on the drive.
  • System Bus or ISA Bus/EISA Bus (Industry Standard Architecture)- The ISA bus was the first PC interface, introduced by IBM on the AT computers as the system bus. It was the first 8-bit bus that could run at 8 MHz (8 MB/second of bandwidth) which was upgraded to a 16-bit bus (16 MBps) . it is now being extended to 32Bit and we name it as Extended Industry Architecture (EISA) bus.
  • PCI Bus (Peripheral Component Interconnect) – EISA replaced by PCI as the system bus for our home computers , PCI is now a standard bus on PCs , Macintosh, Sun, and Alpha machines. PCI is a 32-bit bus operating at 33 MHz (133 MBps). The PCI standard supports a 64-bit (266-MBps) .
  • SCSI Bus (Small Computer System Interface) – A high-performance device interface, it is designed not only for hard drives but also for scanners, optical drives, and other high-capacity and high-bandwidth devices , not necessarily mounted inside the computer.


By definition a port can be defined as a city with a harbor where ships can load or unload. In computer, a port is a type of electronic, software or programmatic docking point through which information can flow within our computer or outside from our computer..

Latest Motherboard Example

Now-a-days , we have latest motherboard examples such as “arduino” board, with a microcontroller chip named AVR microcontroller .

These motherboards used for switches , sensors and lights .  Arduino boards are able to read inputs – light on a sensor, a finger on a button, or a Twitter message – and turn it into an output – activating a motor, turning on an LED, publishing something online. You can tell your board what to do by sending a set of instructions to the microcontroller on the board


Hardware Definition

To define computer hardware, it is the collection of physical parts of a computer system which includes the case, keyboard, mouse and monitor along with inside parts which includes hard disk, motherboard, video card, RAM, processor, PCI cards and many others.

Basic components of the computer

  1. Input devices
  2. Output devices
  3. CPU or Process
  4. Memory Unit
  5. Storage Unit

Basic Components of the Computer

Basic Input Devices , Output Devices and both Input/Output Devices

Input Devices:

  1. Tablets(graphical or digital)
  2. Cameras
  3. Video Capture Hardware
  4. Trackballs
  5. Barcode reader
  6. Digital camera
  7. Gamepad
  8. Joystick
  9. Keyboard
  10. Microphone
  11. MIDI keyboard
  12. Mouse (pointing device)
  13. Scanner
  14. Webcam
  15. Touchpads
  16. Pen Input
  17. Microphone
  18. Electronic Whiteboard
  19. OMR(Optical Mark Recognition)
  20. OCR(Optical Character Recognition)
  21. Punch card reader
  22. MICR (Magnetic Ink character reader)
  23. Magnetic Tape Drive

Output Devices:

  1. Monitor (LED, LCD, CRT etc)
  2. Printers
  3. Plotters
  4. Projector
  5. LCD Projection Panels
  6. Computer Output Microfilm (COM)
  7. Speaker(s)
  8. Head Phone
  9. Visual Display Unit
  10. Film Recorder
  11. Microfiche

Both Input–Output Devices:

  1. Modems
  2. Network cards
  3. Touch Screen
  4. Headsets (Headset consists of Speakers and Microphone. (Speaker act Output Device and   Microphone act as Input device)
  5. Facsimile (FAX)  (It has scanner to scan the document and also have printer to Print the  document)
  6. Audio Cards / Sound Card

Software Definition

Computer Software Definition is a general term used to organize the collection of computer data and instructions. We can describe the computer software definition into two main categories: one is system software used for non-task-specific functions and other is application software, used by user for specific tasks.

Types of software

Application software – is the programs that users use to complete any specific task Examples of applications include word processors, database programs, Web browsers, development tools, drawing, paint, image editing programs, and communication programs. Application software is platform for user.

System software- is mainly the operating systems and any program that supports application software. Systems software are the programs that are dedicated to managing the computer itself, such as the operating system, file management utilities, and disk operating system (or DOS).

Middleware – is sometimes used to describe programming that provides bridge in between application and system software. for example, using a application software designed on Windows and we want to use on Unix , the middleware will help from using in between two platforms . .

System Unit

System unit can be defined as a house of all connections of peripherals, along with the disk drives and removable storage media such as CDs and USBs.

 The Back of the System Unit includes ports – the term port can be defined as the connection points at the back of the system unit:

  1. Power input – it is where to plug in the PC’s electrical power cord
  2. Keyboard port – this special dedicated port is just for the keyboard
  3. Mouse port – this special dedicated port is just for the mouse
  4. USB (Universal Serial Bus) ports – are general-purpose connectors found on newer PCs
  5. Serial port – this 9-pin connector is one of the oldest and most universal ports found in the back of a PC. Before the introduction of USB in the mid 1990s, serial ports are heavily used.
  6. Parallel port – virtually as old as the serial port, the 25-pin parallel port has been updated a number of times over the years. Despite the growing prominence of USB, it remain a popular means for connecting printers.
  7. Video port – this unique three-row, 15-pin connector is where the monitor connects to the system unit
  8. Audio ports – these are used to connect speakers, microphones, and other audio devices
  9. Game port – also known as a joystick port, this 15-pin port connector can be used both joysticks and for MIDI musical devices
  10. Modem port – this looks like a telephone jack

Modems enable one computer to communicate with other computers via a telephone line

There are two connectors in a modem: one is an IN jack, which is use to plug the computer into the wall jack, and the other is an OUT jack, which is use to plug in telephone

  1. Network Interface – it is not a port and sometimes referred to as an Ethernet connector. It connects a PC to other PCs in a Local Area Network (LAN).