Dealing with computer fundamentals, history of computers, generations, functions of varios units, Types of OS etc

1. A computer is an electronic device.
It can perform varieties of operations
according to a set of instructions
(Program).
Computer is a data processor machine
that can perform numeric arithmetic
or logic operations and substantial
computation.

2. Computer is a device capable of
solving problems by accepting
data, performing described
operations on the data and
supplying the result of these
operations.
Various types of computer are
calculators, digital computers and
analog computers

6. The discovery of zero by Indian
mathematicians laid the
foundation on number system.
The first manual counting device
was Abacus developed in n around
3000 BC used in China and later in
European countries.

8. In early 17th Century John
Napier(Scotland)developed a
calculating device called Napier’s
Bones using a set of 7 rods with
numbers carved on them.

10. In 1642, French physicist Blaise
Pascal designed n developed the
first mechanical calculator known
as Arithmetic Machine.

12. In 1671, Leibnitz, a German
Mathematician invented the first
calculator which performed all the
four arithmetic operations.
In 1820, Charles Xavier Thomas
(France) developed a key driven
calculator.

13. In 1823, Charles Babbage (England)
developed first mechanical
computer called Differential
Engine and later Analytical Engine.

16. Lady Ada Lovelace developed the
binary number system for Babbage’s
machine.
In 1854, an English mathematician
George Boole, developed two state
algebra named as Boolean Algebra.
In 1880 keyboard machines were
originated in USA.

17. In the same year Dr Herman
Hollerith first put the punch card
techniques to use computation.
In 1890, he designed census
machine (a punched card device)
to process census data.

20.  In 1911 the first keyboard calculator was
introduced by R Monrol.
 The first electro-mechanical calculator was
designed in 1937. by Dr Howard Aiken
 The first electro digital computer ABC was
developed by Dr John V Atansoff.
 It was the first entirely electronic
computer.

22.  1st Generation Computer (1946-1958)
 2nd Generation Computer (1959-1964)
 3rd Generation Computer (1965-1974)
4th Generation Computer (1975-1980)
 5th Generation Computer (1980-till
date)

23.  Electronic Circuit: Vacuum Tubes
 Storage: Mercury relay lines, Magnetic Drums
 Programming Language: Machine Language, Symbolic
Language
 Low storage Capacity: 1 kb-4kb
 Cycle time was in milliseconds
 Processing speed: 2000 IPS
 Application: Scientific calculation, record keeping, pay
processing
 Disadvantages: Heat and maintenance problem, expensive,
bulky and huge size, slow operation, low level of accuracy
and reliability, high power consumption

24.  Features:
 Use of semiconductor transistor
 Data Storage: Magnetic core memory, Magnetic tape
 High level programming language
 Faster I/O, higher speed, smaller size
 Computation time in microseconds
 Large storage capacity
 Disadvantage:
 Air-conditioning required, frequent maintenance,
commercial production difficult, manually assembly
of components

25.  Features:
 Use of integrated circuit replacing transistors
 Better storage and improved I/O devices(VDU, MIR, High
speed line printers etc)
 Data storage: Solid state memory
 High level programming language
 Cycle time reduced to nanoseconds
 Processing speed: 10 MIPS
 Disadvantages:
 Air-conditioning required, highly sophisticated technology
required for the manufacture of IC chips.

26.  Features:
 Electronic circuit- LSI, VLSI, VHSiC and
microprocessors.
 Processing Speed- 1000 MIPS
 Smallest size, very reliable
 Cheapest among all generations
 Disadvantage:
 Complex Technology

27.  Features:
 Parallel structure
 Will be multitasking simultaneously
 Will not be algorithmic
 Will be knowledge processing.
 Applications will be based on expert systems
 Very cheap with super speeds
 Decision making capabilities
 Disadvantage:
 Highly sophisticated technology

28.  Speed
 Accuracy
 Versatility
 Diligence
 Storage capacity
 Reliability
 Automation

29.  Lack of intelligence
 Lack of decision making power
 Need of program, systems and languages
 Data dependency
 Zero IQ
 Need of proper environment
 Cost
 Compatibility
 Standardisation

31.  Hardware: The physical and tangible components
of the computer.
 Ex: CPU, Printer, Mouse, Keyboard, Hard disks etc
 Software: Software is the set of programs that
govern the operations of a computer system.
 Procedure: The rules, regulations and methods
through which the computer responds to software.
 User: Who operates computer HW and develop SW.
 Data: Unprocessed raw facts and figures.
 Connectivity: The system of connecting two or
more computers through phone, satellite,
microwave etc

32. Input Unit
Central Processing Unit
Output Unit

33.  Functions:
 Input unit accepts data or reads data instruction
from user.
 It converts data instruction into computer
acceptable form.
 The converted instruction data passes to the
computer for processing.
 Examples
 Keyboard, Mouse, Joystick, Light pen, Touch
screen, scanner etc.

34. The CPU is considered to be the
brain of computer.
 It performs data processing which
includes arithmetic operations,
 logical operations and problem
solving.
Add to this it controls the
functions of all other units.

35. The CPU is subdivided into 3
units
Storage Unit
ALU
CU

36.  Function:
 The data and instructions that are entered
into the computer before processing and the
results produced by the computer after
processing must be stored inside the
computer.
 The memory unit is responsible for storing
data, instructions and results.
 It consists of a large number of cells each
capable of storing one unit of information
(word).

37.  Functions:
The ALU performs all the basic
arithmetic operations and logical
operations.
The ALU is responsible for actual
execution of instruction during
process operation.

38.  Function:
The control unit monitors and controls the
entire processing.
Whenever input reaches into memory the
CU determines what type of instruction it
and accordingly it instruct the ALU.

39.  Functions:
 Output unit accepts the result processed by
CPU in coded form.
 It converts the coded results to human
acceptable form.
 It produces the result to user.
 Example:
 Monitor, Printer, Plotter etc.

40.  Software is a collection of computer
programs, procedures and documentation
 It performs different tasks on a computer
system.
 John Tukey in 1958 first used the term
software.
 Types of computer software
 System Software
 Application Software
 Utility Software

41.  Function:
 System Software controls internal computer operation
like reading data input devices, transmitted process
information to output device checking system
components, converting data or instruction to computer
understandable form.
 Example:
 DOS, Windows, BASIC, COBOL, PC TOOLS.
 These software are developed by system programmers.
 System software can be further divided into 3 types
 System Management Software (OS, DBMSs, Operating
environments)
 System Development Software (Language Translator,
CASE TOOLS etc)
 System Software Utilities

42.  Application software is a set of programs
necessary to carry out operations for a specified
program.
 Application software are developed using system
software by application programmers.
 Types:
 Packages (Database management package, Word
Processors, Spreadsheets etc.)
 Customized Software (Accounting, Inventory,
Production Management etc.)

43.  An operating system makes the computer ready to use
by a process called booting.
 When we switch on a computer, the instructions
stored in ROM are automatically executed.
 These instructions help the computer load the OS
from external storage device to internal storage
(RAM).
 This process of loading of OS from disk to RAM is
called booting.
 Types of OS
 Single - user OS
 Multi - user OS


44.  These operating systems are used for
computers having one terminal.
 Examples:
 MS-DOS (Microsoft Inc. 1981)
 PC DOS (IBM)
 OS/2 (jointly Microsoft Inc. and IBM)
 Windows NT (Microsoft Inc. 32 bit
microprocessor)
 OS/2 was the first OS that provided users with
GUI.

45.  Multi user operating systems are used for
computers having many terminals.
 Examples:
 UNIX, NETWARE, MVS, OS/400, VMS and
Linux.
 UNIX- developed by AT & T in 1969.
 NETWARE: developed by Novell Inc.
 MVS - (Multiple Virtual Storage)- developed
for IBM mainframes.
 VMS - (Virtual Memory Storage)
 Linux – the first free OS.

46.  System software utilities support the
operation of the computer.
 They provide many features which
includes
 file management capabilities
 data compression
 diagnostic routines
 virus detection and removal
 text editing
 performance monitoring
 spooling.

47.  File management utilities:
 Norton Utilities and PC TOOLs
 Data compression utilities:
 PKZIP, PKUNZIP
 Diagnostic utilities:
 Norton Disk Detector, QAPlus, Disk Manager
 Virus detection utilities:
 SmartDog, Nashscan etc.
 Text editing utilities:
 Norton Editor
 Performance and Monitoring utilities
 QAPlus, PC TOOLs, Norton Utilities
 Spooling (Simultaneous Peripheral Operations Online)