Application Software
Application Software is the set of programs necessary to carry out operations for a specified application. This type of software pertains to one specific application. For instance, software that can perform railway reservation functions cannot prepare result for a school. These are programs written by programmers to enable computer to perform a specific task such as processing words, inventory control, handling calculations and figures, medical accounting, financial accounting, billing, etc.
Application software can further be subdivided into 3 categories:
General Purpose software
Packages that may be used by individual users in the manner it suits their needs and requirements. Major categories are word processing software, spreadsheets, database management systems, desktop publishing software, graphics and multimedia and presentation applications.
Specialist software
Applications designed to be used for specific tasks such as company payroll, stock control systems, appointment systems, e-commerce sites, etc.
Some examples are Library Ex+ for library management, Tally for financial accounting, etc.
Customized software
This type of software is tailor-made software according to the user's requirement. This type of software is developed to meet all the requirements specified by the user. For instance, a company wants to computerize its 'Accounts Department' and gets software developed according to the user's needs. This is also known as tailor made or bespoke software. (See Figure 4.4.4)
Match the following
A B
1. Customizes software i. Spreadsheets
2. Specialist software ii. Tailor-made
3. General purpose software iii. Tally
(A) 1, ii; 2, iii; 3, i
(B) 1, iii; 2, ii; 3, i
(C) 1, i;2, ii; 3, iii
(D) 1, ii; 2, i; 3, iii
(E) 1, i; 2, iii; 3, ii
Answer: (a)
Correct Option:
(A) Option (A) is matched correctly.
Incorrect Options:
(B) Option (B) is matched incorrectly.
(C) Option (C) is matched incorrectly.
(D) Option (D) is matched incorrectly.
(E) Option (E) is matched incorrectly.
Fill in the blanks:
1. _________ is the set of programs necessary to carry out operations for a specified application.
2. _________ applications designed to be used for specific tasks.
3. _________ is also known as
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First generation and second generation
First Generation Languages IGLs (Machine Language)
When the human being first started programming the computer, he used machine language or binary language. A set of is and Os as 11101101 has a specific meaning to a computer even though it appears as a binary number to us. The writing of programs in machine language is very cumbersome and complicated and could be performed only by experts. All the data and instructions to be fed into the computer were in a numeric form i.e. in binary form. The machine language program is a complicated program which requires the knowledge of complete computer circuitry. Furthermore, debugging a machine language program is a tedious job. Due to these reasons the machine language never became popular among the users.
Introduction
You communicate with your family and friends by speaking languages like English, Hindi or your mother tongue. A computer can understand only binary language because it operates upon electricity. Electric signals have two states - ON or OFF (or to be very specific - high voltage or low voltage.) If we denote ON by 1 and OFF by 0, it becomes a binary language i.e. a language with just two symbols. For the computer 1 means "Yes, there is power" and 0 means "No, there is no power". Thus, it can understand only electric signals and the computer can understand binary language as it symbolizes electric signals. A computer follows the instructions given by the programmer to perform a specific job, such as add, read a file, etc. This sequence of instructions is known as a program. A program written for a computer is known as software. The computer understands only the binary language which is also known as Machine Language or Low Level Language. Earlier programs were written only in machine language in which each instruction was in the form of long strings of Is and Os. These programs were understood by the computer but not easily understood by human beings. Therefore the computer remained a mystery to the common man till High Level Languages were developed. The journey of the computer software from the machine language to high level languages is an interesting one which we will discuss in some detail in this chapter. 
System
Software
System software refers to the programs that
controls internal computer operations and make the best use of the hardware.
The software that controls internal computer operations (reading data from
input devices, transmitting processed information to the output devices,
checking system components, converting data/instructions to computer
understandable form) is known as system software. System software offers a
protective shield to all software applications. It also provides support to the
physical components of computers. System software coordinates all external
devices of computer system like printer, keyboard, displays, etc. It can be
further classified as - operating system, language processors, device drivers
and utilities.
Operating
System
The operating system is just like a secretary
who does all the work for the boss. The primary goal of an operating system is
to make the computer system convenient to use and the secondary goal is to use
the computer hardware in an efficient manner. A boss may ask his secretary to
fix an appointment with another person, reserve a seat in the seminar, find out
the status of a project, etc.
Similarly
when you ask the operating system to do things such as:
v
Copy A dat.
v
Delete myfile.dat
v
Type readme.doc
You assume that the operating system knows
how to perform copy or delete or type. The user does not have to know how the
operating system does this. An operating system is a master control program
which controls all other components of it. The major components are the
hardware, the OS, the human ware (users) and the application program routines
like compiler, linkers, database management systems and utility programs. Where
hardware provides the basic computing resources, the application program
routines define the ways in which these resources are used to solve the
computing problems of the users. The OS controls and coordinates the use of the
hardware among the various application programs for the various users. (See
Figure 4.4.2)
Varieties of Computer Software
Computer software comes with many different forms. Broadly the entire computer software system can be categorized as system software and application software. System software is the most useful form of computer software. It is used to drive the whole network of hardware and software present in all computer systems. Application software is used for commercial purposes. The application software is widely used in educational, business and medical fields. Industrial automation, databases, business software and medical software prove to be of great help in the respective fields. Educational software is widely used in educational institutes across the globe. We will study about the classification of software in detail in this chapter. (See Figure 4.4.1)
Physical Characteristics
The physical characteristics of a memory device can be categorized into four parts namely, electronic, magnetic, mechanical and optical. Hard disks and floppy disks are examples of magnetic media and CD ROMs and DVDs are examples of optical media. One of the important requirement s of the storage device is that it exhibit two physical states, 0 or 1. The access time of the memory depends upon how quickly the state can be recognized and changed. The quicker the device recognizes the state, the faster will be the access.
Match the following
A B
1. Magnetic Media i. DVDs
ii. Floppy disks
2. Optical Media iii. ROMs
iv. Hard disk
(A) 1- ii, iii, 2- i, iv
(B) 1- ii, iv, 2- i, iii
(C) 1- i, iii, 2- ii, iv
(D) 1- iv, 2- i, ii, iii
(E) 1- ii, iii, iv, 2-i
Answer: (B)
Explanation
Correct Option:
(B) Option (B) is matched incorrectly.
Incorrect Options:
(A) Option (A) is matched incorrect.
(C) Option (C) is matched incorrect.
(D) Option (D) is matched incorrect.
(E) Option (E) is matched incorrect.
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Permanence of Storage
Some memories retain information for longer duration while others are used to store information for a very short period. There are memories which require constant refreshing to preserve the information; these memories are called dynamic memory, these memories are volatile in nature and lose contents on power failure. Another memory, which retains memory forever, is called static memory. This comes under the non-volatile category. As you have learned earlier, RAM is volatile memory and ROM is non-volatile memory
Fill in the blanks:
1. __ is and __ is a volatile memory.
2. The memory which retains memory forever is called ____ memory.
3. Some memories require constant refreshing to____________ the information.
(A) RAM, ROM, Dynamic, Preserve
(B) ROM, RAM, Static, Preserve
(C) PROM, SRAM, Static, Destroy
(D) CD, DVD, Dynamic, Destroy
(E) RAM, ROM, Static, Preserve
Answer: (B)
Explanation
Correct Option:
(B) Options given in (B) are correct.
Incorrect Options:
(A) Options given in (A) are incorrect. Therefore, option (A) is incorrect.
(C) Options given in (C) are incorrect. Therefore, option (C) is incorrect
(D) Options given in (D) are incorrect. Therefore, option (D) is incorrect.
(E) Options given in (E) are incorrect. Therefore, option (E) is incorrect.
Access Time
Access time is the time required between the requests made for read/write operations and the time it takes for the completion of the request. Generally, it is measured for read operations only. The access time depends upon the physical characteristics and the access modes used for that device. Primary memory has a faster access time as compared to secondary memory. The time taken to access a given byte of information stored on a hard disk is typically a few thousandths of a second or milliseconds. By contrast, the time taken to access a given byte of information stored in random access memory is measured in billionths of a second or nano seconds. In disk drives, disk access time is the time required for a computer to process data from the processor and then retrieves the required data from a storage device, such as a hard drive.
Sam and Peter are discussing about the accessing time of a computer. Read their conversation and identify who is correct.
Sam: Access time is the time required for completing a file on which you are working. And it is measured for write operations only.
Peter: The access time depends upon the physical characteristics and the access modes used for that device.
(A) Sam is correct
(B) Peter is correct
(C) Both are partially correct
(D) Both of them are correct
(E) None of them are correct
Answer: (B)
Explanation
Correct Option:
(B) Statement of Peter is correct about access time of a computer.
Incorrect Options:
(A) Statement of Sam is incorrect about access time of a computer. Therefore, option (A) is incorrect.
(C) Sam is fully correct whereas Peter is fully incorrect. Therefore, option (C) is incorrect.
(D) Both of them are not correct. Only Sam is correct. Therefore, option (D) is incorrect.
(E) Both of them are not incorrect. Only Peter is incorrect. Therefore, option (E) is incorrect.
Access Modes
Memories can be divided into different categories based on what memory cells can be accessed at a given instant.
The information from the memory can be accessed in the following ways:
Random Access Memory
Random Access indicates that locations in the memory can be accessed, that is, written or read, in any order regardless of the memory location that was accessed before. RAM, Floppy and hard disk are the examples of random access memories.
Fill in the blanks:
1. Sequentially Access is accessed by _____ through each memory location until the desired location is reached.
2. In the magnetic disk _______ type of mode exists.
3. ________indicates that locations in the memory that can be accessed, regardless of the memory location that was accessed before.
(A) Random access, Stepping, Random
(B) Directly, Direct, Sequentially access
(C) Stepping, Semi-random, Random access
(D) Indirectly, Direct, Direct access
(E) Stepping, Fully-random, Direct access
Answer: (c)
Explanation
Correct Option:
(C) Options given in (C) are correct.
Incorrect Options:
(A) Options given in (A) are incorrect. Therefore, option (A) is incorrect.
(B) Options given in (B) are incorrect. Therefore, option (B) is incorrect.
(D) Options given in (D) are incorrect. Therefore, option (D) is incorrect.
(E) Options given in (E) are incorrect. Therefore, option (E) is incorrect.
Storage Capacity
Storage capacity refers to the size of the memory. Secondary memory like the hard disk has more storage capacity as compared to RAM. A large primary memory provides higher speed and a large secondary memory provides more space to store data and instructions. Bit is the smallest measuring unit of computer memory. It means binary digits (1 and) more like we use kilograms and grams to measure weight, the capacity of the internal processor memory of the computer is expressed in terms of number of bytes and kilobytes.
Capacity is the number of bytes (characters) a storage medium can hold. A table displaying the storage capacities of some memory devices is the following: (See figure 4.3.1)
