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Information System - I
Part I
Part II
Part III
Draw the Well labeled Block Diagram of computer organization. Explain functions of block. Discuss characteristics of computer.
Definition : Computer is an electronic device which processes raw-data and convert to give meaningful information.
Block Diagram of Computer

CPU(Central Processing Unit )
CPU is a component of a Computer System with the circuitry to control the interpretation and execution of instructions. It performs the process part of INPUT-PROCESS-OUTPUT Cycle.
In a Microcomputer, the components of the CPU are mounted on the main circuit board, called the ‘Mother Board’.
Component of CPU :
a) ALU
b) CU
c) MEMORY
a) ALU :-
ALU stand for Arithmetic and Logic Unit. ALU is part of a CPU where actual data processing occurs. All Calculation and all comparisons take place in this unit. Every arithmetic step requires at least two numbers and then it produces a result.
In addition to arithmetic functions, the ALU also performs logic functions. A logic function is one where numbers or conditions are compared to each other.
CU :
CU stand for Control Unit. This interprets any instruction it receives from memory and directs the sequences of events necessary to execute the instruction. CU uses a system clock which synchronizes all tasks by sending out electrical pluses. Clock Speed is measured in MHz.
Memory
Memory is a Brain of Computer. There are two types of Memory.
1) RAM 2) ROM.
Main Memory is used for four activities – Input/Output operations; Manipulation of text and calculation operations; Logic/Comparison operation; Storages and retrieval operations. The Main Memory of a computer has many small storage areas. Each storage area is assigned an address – an identification that designates a particular location in storage or any other data source.
Input Device :
Output Device :
CHARACTERISTICS OF COMPUTERS
1) Speed :- This is the most important characteristic of a computer. Computers can work at a speed of milliseconds, microseconds, & nanoseconds. i.e. it is capable of processing millions of instruction per second. The speed is measured in Hz.
2) Accuracy :- The results produced by a computer are very accurate. Errors, if any, are produced due to faulty data or wrong set of instructions. Thus if a wrong input is given, the output will be wrong.
3) Versatility :- Computer are very versatile machines i.e. they can be used to perform a variety of tasks ranging from very simple to very complex. They can be used to perform calculations, type letters, play music and movies, communicate with other computer across the world, play games etc.
4) Reliability :- Computer consistently produce accurate results and hence are very reliable.
5) Storage :- Computer can store a large amount of data which can be accessed very fast whenever required. Data like characters, numbers, graphical images etc. can be stored.
6) Reduced Cost :- with the ever-increasing advances being made in the state of the art, the cost of computer equipment has dropped drastically over the years. Hardware costs have been decreasing at an estimated annual rate of 25 %.
Q. Explain the function of computer. ( win 05,
Functions of Computer
All Computer perform the following five basic functions :
1) Inputting :- The process of entering data and instructions into the computer system.
2) Storing :- Storing data and instructions to make them easily available for initial or additional processing, as and when required.
3) Processing :- performing arithmetic operations ( add, subtract, multiply, divide etc.) or logical operations on data to convert them into output.
4) Outputting :- The process of producing useful results for the user on monitor or printer.
5) Controlling :- Directing and controlling the sequence in which all the above operation are performed.
Q. What is Computer? What are the types of computer? Explain in details. Discuss characteristics of computer.
Definition : Computer is an electronic device which processes raw-data and convert to give meaningful information.
1) Analog Computer
This is a computer that can process analog data. These computers recognize data as a continuous measurement of a physical property. The output is graphically represented.
Ex. :- Auto¬mobile Speedometer, CRO,
2) Digital Computer
This is a computer that can process discrete data. These are high speed programmable, electronic devices that perform mathematical calculations, compare values and store the results. The computers is done in a finite number system with data in the form of binary digit (o or 1). A group of 8 bit is called a Byte. Most of the present day computer are digital.
Ex. :- Personal Computer
3) Hybrid Computer
Hybrid computer are the Combination of Analog and Digital Computer. This system finds application in areas of scientific research.
Type of Digital Computer
1) Super Computer :-
A super computer is generally characterized as being the fastest, more powerful and most expensive computer. These computer consist thousands of integrated microprocessors. Super computers are mainly designed to maximize FLOPS (floating point operation per second.) rating. First Cray supercomputer was introduced in 1976 – the Cray-1. One of the most powerful super computer today, the Cray -2 is set up in a c-shape. They are used in research application like in petroleum industry, defence, Automobile industry, Space applications etc. PARAM is a India’s First Super computer.
2) Mainframe Computer :-
A mainframe computer is usually slower, less powerful and less expensive than supercomputer. Mainframe process data at several million instruction per second. (MIPS). These machines are very big in size (as long as a room and are mainly used for extensive application like in airline system, bank etc.
3) Mini computer :-
Mini Computer are special purpose computer with a very powerful processor, they are smaller than mainframe. These type of computer are widely used in large manufacturing organization for distributed data processing. They are expensive and with a large data storage capability.
4) Micro computer :-
A micro computer is the smallest, less expensive of all the computers. The prefix “Micro” refers mainly to the physical size of the computer and its circuitry rather than its capabilities.
The essential difference between microcomputers and mainframe or mini computer are that microcomputer have smallest memory and less power. Microcomputer are also called personal computers.
Q What is Computer? What are the types of computer?.
Primary memory :- The main memory or internal memory or the primary memory is also known as immediate access store. The main memory holds the data and program needed by the CPU. The CPU reads the data & programs kept on secondary storage into the main memory.
Each character is represented through at least 1 byte. So byte is a measuring unit for memory. Following are all units of memory.
4 bits = 1 nibble 8 bit = 1 bytes 1024 byte = 1 KB 1024 KB = 1MB 1024 MB = 1GB Type of primary memory :
a) Semiconductor Memory
b) Magnetic Memory
c) Bubble Memory
RAM :- Ram Stand for Random access memory. Ram is a Temporary memory. RAM is a volatile memory. RAM is a Semiconductor memory. This is the main store and is the place where the programs and software gets stored. Ram is a primary memory. CPU stores the result of calculations in RAM. RAM can access the data random or directly which increases the processing speed.
There are 2 types of RAM
a) Dynamic RAM
b) Static RAM
Q.) Define Memory. Give its Classification. Explain the Secondary Memory in details.
Memory is a Brain of computer. Memory is that part of CPU where data or set of instructions is temporarily stored.

Classification of Memory
There are two type of Memory a) Primary Memory b) Secondary Memory
a) Primary Memory
The main memory or internal memory or the primary memory is also known as immediate access store. The immediate access store the data and program needed by the CPU. The CPU reads the data & program kept on secondary storage into the main temporarily, because secondary storage is much slower than the main memory and the CPU.
RAM :- Ram Stand for Random access memory. Ram is a Temporary memory. RAM is a volatile memory. RAM is a Semiconductor memory. This is the main store and is the place where the programs and software gets stored. Ram is a primary memory. CPU stores the result of calculations in RAM. RAM can access the data random or directly which increases the processing speed.
There are 2 types of RAM
a) Dynamic RAM
The storage cell circuits in dynamic RAM chip contain :
i) A Transistor that acts like a mechanical on-off light switch
ii) A capacitor that is capable of storing an electric charge.
b) Static RAM
It also provides volatile storage, but as long as it is supplied with power. It needs no special regenerator circuits to retain the stored data. State RAM chips are more complicated and take up more space that dynamic RAM chips because they require more transistors.
ROM : ROM Stand for Read Only Memory. Rom is non-volatile Memory. ROM is Permanently stored memory. The ROM memory is used to storing special sets of instructions which the computer needs when it starts up.
i) PROM : PROM Stand for Programmable read only memory is like a textbook. It is a blank textbook nothing is written in it. You can write on it only at once after that you can only read whenever you desire. Such a chip is used for keeping some information or program permanently for future use.
ii) EPROM : EPROM Stand for Erasable Programmable read only memory is modification of the PROM chip in the sense that using ultraviolet light can erase the bits stored in the chip. It is like a slate.
iii) EEPROM : “Electrically Erasable Programmable Read only memory can be reprogram with special electrical pulses.
Cache Memory :
The cache memory is placed in between the CPU and the main memory. It is much faster than main memory. Its access time is much less compared to that of the main memory.
The cache memory is not accessible to users. It stores instruction and data, which to be immediately executed. It is used to reduce the average access time for address, instructions or data, which are normally stored in the main memory. Cache memory is much costlier than main memory.
Flash Memory :
Electronic memory comes in a variety of forms to serve a variety of purposes. Flash memory is used for easy and fast information storage in such devices as digital cameras and home video games. It is more as hard drive then as RAM. It is non-volatile in nature.
Secondary Memory :
This memory supplements the main storage. This is a long-term, non volatile memory. The term non-volatile means that stores and retains the programs and data even after the computer is switched off. You can read data from or write data into secondary memory Auxiliary devices are used to store data permanently.
Q. Explain the Generation of Computer.
Generation of Computer
Evolution of modern computer is commonly considered in terms of Generation of Computer. Each new generation has made the following changes in computer Characteristics.
1. Increase in Speed.
2. Increase in storage capacity.
3. Increase in reliability
4. Reduction in system cost.
Let us consider some of the characteristic of each generation.
First Generation : ( 1946 – 1955)
Introduction of the UNIVAC in 1951 marked the beginning of the first generation.
General features of these computer were :
1) Electronic circuitry used Vacuum tubes.
2) Punched Cards used for feeding information.
3) Punched cards and paper used for getting results.
4) Magnetic tapes were used for external storage.
5) Bulky in a Size.
6) Air Condition can be required.
7) Lot of Heat Generated.
8) High Cost Vacuum Tubes are use a s a Primary Memory.
9) More hardware Failure.
10) Machine Language & Assembly Language are used.
11) Power Consumption too high.
12) Non portable
13) Ex. of the generation computers : UNIVAC, IBM 700 Series , IBM 701, 704, 704
Second Generation : ( 1956 – 1965)
The transistors invented by Bell Telephone Laboratories in 1948, formed the basis for the second generation of computers. Through use of the transistor, these computer were much faster, more reliable and more versatile than First Generation of Computer.
Some Principle Characterized of Second Generation of computer.
1) Electronic circuitry by use of Transistor.
2) Punched Cards & magnetic tape used for Input Device.
3) Punched cards and paper used Output device.
4) Magnetic core storage i.e. magnetic tape used for external storage.
5) Small in Size and less expensive as compared to First Generation Computer.
6) Air Conditioning required.
7) Less Hardware Failure, better portability.
8) More reliable, less heat generated.
9) Frequent maintenance required.
10) High Level Language (fortran, Cobol, Basic) are used.
11) Ex. of the generation computers : IBM 1400 Series , IBM 7000 series,
Third Generation : (1965-1971)
Advances in electronics continued and the advent of “microelectronics” technology made it possible to integrate large number of circuit elements into very small surface of silicon known as chip. This new technology is called as IC (Integrated Circuit) technology.
Principle Characterized of Third Generation Computer .
1) Electronic Circuitry by use of IC.
2) Keyboard were introduced for data input.
3) Monitor were introduced for data output
4) Magnetic disk/drum/tapes were used as secondary memory.
5) High Performance printer were introduced.
6) More High Level Languages including PASCAL, RPG ( Report Program Generator) Were developed.
7) Smaller in size and more powerful as compared to 1st & 2nd generation computers.
8) More reliable and easily affordable than 2nd generation.
9) Less heat generated, Less hardware failure.
10) Less maintenance cost.
11) Easily portable.
12) Ex. IBM system 360, IBM 370 series. CDC 6600, PDP 8, PDP 11
Fourth Generation : (1971-1989)
The significant distinction for fourth generation is the development of Large-Scale Integration (LSI) and Very Large scale Integration (VLSI). Magnetic core memories were replaced by semiconductor memory size of 16 MB. Hard disk provided a low cost, high Capacity storage. Computer networks like LAN and WAN and distributed computer system were developed. Several new operating system like MS-DOS, MS-Windows were developed.
The Characteristics of fourth generation computer are as follows.
1) Electronic Circuitry by use of LSI & VLSI.
2) Keyboard, Mouse, Monitor, Printer used for input & output.
3) Introduction of Microcomputer.
4) RAM(Random Access Memory) were uses as a Primary Memory.
5) They consumed much less power than third generation computer
6) They were more reliable and less hardware failure than third Generation computer.
7) They were totally general-purpose machines.
8) During the 4th generation period, the UNIX operating system and the C Programming language became popular.
9) They had faster and larger primary and secondary storage as compared to 3rd generation computers.
10) Ex. IBM PC, Apple II, CRAY-X/MP, VAX 9000, Intel 80486, 80586, 80686
Fifth Generation : (1989 onwards)
The dramatic increase in the power of microprocessor chips and capacity of main memory and hard disk continued in the fifth generation.
The VLSI Technology became ULSI (Ultra Large Scale Integration) technology in fifth generation, resulting in the production of microprocessor chips, having ten million electronic components. If fact, the speed of microprocessors and the size of main memory and hard disk doubled almost every 12 months.
During fifth generation optical disks also emerged as a popular portable mass storage media, commonly known as CDROM. It had a storage size of 650 MB on 5.25” disk. DVD ROM (digital Versatile Disk) with storage capacity of 17 GB emerged in 1998.
The Characteristics of fifth generation computer are as follows.
1) Desktop PCs are several times more powerful than the PCs of fourth generation.
2) They consume much less power than fourth generation computers.
3) They are more reliable and less hardware failure than fourth generation computer.
4) Use of standard high level languages allows programs written for one computer to be easily ported to and executed on another computer.
5) More powerful applications, including multimedia applications, make the system more useful everywhere.
6) Ex. Intel P1, P2, P3, P4, Celeron, Intel Core 2 Duo, Intel Dual Core,
Q.Explain the classification /type of Computer ?
Classification of Computer
1) Analog Computer :-
This is a computer that can process analog data. These computers recognize data as a continuous measurement of a physical property. The output is graphically represented.
Ex. :- Automobile Speedometer, CRO,
2) Digital Computer :-
This is a computer that can process discrete data. These are high speed programmable, electronic devices that perform mathematical calculations, compare values and store the results. The computers is done in a finite number system with data in the form of binary digit (o or 1). A group of 8 bit is called a Byte. Most of the present day computer are digital.
Ex. :- Personal Computer
3) Hybrid Computer :-
Hybrid computer are the Combination of Analog and Digital Computer. This system finds application in areas of scientific research.
Q Discuss Secondary Storage Devices.
Many a times a computer’s primary storage capabilities are insufficient and unable to handle the instructions and data needed for processing. Primary storage as we know is volatile so the question arises as to what can we do to have a permanent storage of data which can hold as much data as one can think of use.
1) Floppy Disk
It is a small flexible mylar disk coated with iron-oxide on which data are stored. These disks are available in three sizes.
a) 8 inch portable floppy disk
b) 51/2 inch portable floppy disk
c) Compact floppy disk measuring less than 4 inches in diameter - The 3 ½ inch diameter miniature diskettes are individually packed in a hard plastic case. This case has a dust-sealing and finger proof shutter which opens automatically once the case is inserted in its disk drive.
A Floppy disk may be single sided (can be recorded on Only single side of the disk) or double sided (can be recorded on both side of the disk). The most commonly use diskettes are :

2) Hard Disk
This is the most commonly used and the primary secondary storage device. It is a random access device i.e. data can be directly read. Hard disk is made from materials such as aluminium instead of mylar. Hard disk is a permanent storage device. The hard disk spins about the spindle at a very high rate of about 3600 rpm & 7200 rpm. The read and write head is moved in order to position it on a specific track. The entire units is encased in a sealed chamber and mounted on a disk drive. Such a disk drive is known as Winchester disk drive. Disk can store data on both side of the disk. The organization of the disk in tracks and sectors is as discussed about under magnetic disk. Each sectors can store up to 512 bytes. Hard disk capacity is currently in Gigabytes (GB) Ex. Seagate, Quantum are popular hard disk manufacturers.
Advantages
1) Direct access to data.
2) Makes data readily accessible at all times
3) Cost per bit of storage low.
4) Can be erased and reused many time.
5) Data transfer rate is higher than the tapes.
6) Suitable for both on line and off line storage.
Disadvantages
1) Not portable
2) A disk crash or drive failure can result in complete data lost.
3) Zip Disk
Several other kinds of removable magnetic media are in use such as the popular zip disk. All of these have a much higher capacity than floppy disk. Large files that are too big for a floppy are now easily stored and transported via the ZIP disk. Zip disks come in two capacities : 100 MB and 250 MB.
4) Optical storage device (Compact Disk )
Its an optical disk. The disk is made up of a resin such as polycarbonate. It is coated with a material which will change its property when high intensity laser beams are focused on it. The coating material is highly reflective, usually aluminum.
It uses laser beam technology for storing of data and hence are also known as laser disks or optical laser disks. For recording data, high intensity laser beams are used (25mW) whereas for reading the data low/less intensity laser beams are used (5mW).
Storage capacity of a CD = Number of sectors * number of bytes
Advantage :
1) High storing capacity i.e. 650/ 700 MB.
2) Removable from the computer.
3) Cost per bit of storage is very low.
4) Easy to handle.
5) Pen Drives/ Flash Drives
USB flash drives/Pen Drives are compact and easy-to-use devices that are similar in use like your computer hard drive. USB flash /Pen drives slip into your pocket. The difference is mostly in price, capacity, design and functions and features. They are pluggable, portable and powerful.
USB Flash/Pen drives share some other characteristics too.
i) Flash drives weigh about the same as a car key.
ii) USE flash drives are about the size of a stick of gum.
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