5. What are the differences between ROM and RAM?

 

ROM (Read only memory)

 

1. You can only read the data.

2. Data can’t be written every time, to write the data we need PROM, EPROM, OR EEPROM.

3. ROM is non volatile in nature. The data stored in ROM is permanent in nature.

4. Size of the ROM has nothing to do with processing.

 

RAM (Random access memory):

 

1. You can read and write data on the chip.

2. RAM has volatile memory. It looses its contents when the power is switched off.

3. Size of the RAM makes difference in the processing i.e., bigger the size of the RAM more is the speed of processing.

4. The data can be read and written at anytime.

 

 

6. What is an operating system? What are its functions?

 

The operating system is a program that acts as an interface between the user and the hardware. It is a collection of programs that coordinates the operations of computer hardware and software.

Functions of an operating system:

 

 Starting the Computer: In most computers, the BIOS and the diagnostic routines are contained in ROM. They are permanently available to other programs to check equipment and perform input/output tasks. In addition, ROM contains a bootstrap loader program that is used to start a computer. The remainder of the operating system is contained in secondary memory. When the computer is turned on, it automatically begins to execute the boot program. This program first runs diagnostic programs to check the status of RAM and of each of the attached system devices. The boot program then reads in the operating system executive program from the disk. The layout of the memory at this stage is shown in figure.

 

 Running application programs: To run an application programs such as word processing program, the user types the name of the program after getting the Dos prompt on the screen. Ex C:\>WS The operating system accepts the command WS and reads the program into RAM. When the application program is in RAM, the operating system executive program gives control of the computer system to the applications programs. The computer then executes the application program. When the application program ends, control is restored to the operating system executive program, which monitors the keyboard for the users’ next command. When the application program is running the operating system manages the allocation of memory. When a user requests that a program be run, the operating system allocates the memory required for the program instructions and for data.

 

 Running utility programs: An operating system includes utility programs that give the user control over various features of the computer system. The utility programs are either residient or transient. Residient programs are always present in RAM; transient program must be read into RAM, as they are requested. Ex. CON: name of the keyboard, or console. PRN: name of the printer. Disk Copy A: B: (copies the contents of the disk in drive A, onto the disk on drive B)    Managing files: Information on the disk is organized into files. A file is collection of Bytes.

 

 

7. What is system software and application software?

 

Software is a set of instructions, programs which enable the computer to perform specified task. In other words, software is nothing but binary code instructions which control the hardware. In most of the organizations the computer is a valuable resource. Among the resources that a computer has are processing time, storage space, printers, terminals and information. The management of these resources is performed largely by a type of system software called an operating system. When users interact with the computer the interaction is with system software. There are two broad categories of software, system software and application software. System software is a set of programs that manage the resources of a computer system, so that they are used in an optimal fashion, provide routine services such as copying data from one file to another and assist in the development of applications programs.   System software consists of programs that assist the computer in the efficient control, support, development and execution of application programs. Application software on the other hand, performs specific tasks for the computer user. System software:

 

They can be broadly classified in to three types:

 

1. System control programs control the execution of programs, manage the storage and processing resources of the computer and perform other management and monitoring functions. Other examples are DBMS and communication monitors.

 

2. System support programs provide routine service functions to the other computer programs and computer users. Ex. Libraries, utilities, job accounting etc.

 

3. System development programs assist in the creation of application programs. System programs are developed and sold by both computer companies and specialized software firms.

 

Application Software:

It is a program written for, or by, a user to perform a specific job. General purpose application software such as electronic spreadsheet has a wide application. Specific purpose application software, such as payroll and sales analysis is used only for the application for which it is designed. The system software controls the execution of the application software and provides other support functions such as data storage.

 

 

8. What is utility software?

 

Utility software consists of programs which are frequently used to carry out routine jobs like sorting, merging, and core dump/list, programmed debugging etc, and are normally provided by the manufactures to make the machine work gainfully.   Certain jobs are performed by every computer and it is a tedious task to write separately for each installation and there will be enormous waste of programmer’s time. Software houses recognized this problem and have produces, wide range of programs to perform these routine jobs, with sufficient inbuilt flexibility to handle all user requirements.  Utility programs are general in nature. Parameters can be used to make them specific to a particular application.

 

The main types of utility software available are:

 

1. File conversion: Transferring file data from one medium to another.

 

2. File copying: Copying records, files, related files from one storage medium to another storage medium.

 

3. Memory dumping: Copying the contents of main store on to output device. Whenever an error occurs or at a check point/restart during the running of an application program, the check point/restart program dumps main store contents at periodic intervals and of something goes wrong the application program can be restarted at the last check point.

 

4. File organization: when a disc file becomes too unwieldy to use, for instance if the over flow areas are almost full, it has to be reorganized in to its original format.

 

5. File maintenance: Enables the user to create, delete and rename records, amend standing data etc.

 

6. Debugging: Provides for outline program testing and error correction during program development.

 

7. Sorting/Merging: Enables records to be reorganized into desired key field sequence. The parameters of a sort program which are to be supplied for each application are:

 

 The key field size and position.

 

 Number and size of records.

 

 Number of tape or disc units available for the sort.

 

 The desired key field sequence.

 

The sort is carried out by sorting small groups of records into the desired sequence in main storage and writing each group on to backing storage, and then merging the strings in to larger ones in main storage, and so on, until the file is stored.

 

 

10. How do you classify the various computer languages?

 

Instructions to the computer are given with the help of computer languages. These languages can be classified as follows

 

1. Machine languages.

 

2. Assembly languages.

 

3. High level languages.

 

Machine language:   Computer uses the binary system. All data and instructions ultimately have to be converted into a combination of binary digit 0’s and 1’s. Each computer system has its own machine language. The language consists of an instruction set for a computer with a standard format.   Machine language program can be executed directly and additional software is not required for translating the instructions into what the computer can understand. Through machine language is efficient it is rarely used for writing programs, as it is very cumbersome.

 

Assembly language:   This language was designed to facilitate writing programs. In this method mnemonic codes are used by the programmer rather than binary digits. For ex.: Instead of using “0010” which represents the add operation in machine language, programmer use, a mnemonic code “add” directly.   Similarly, a symbolic code for memory address of operand can be used instead of specifying the address in binary system. Auto coder is an example of assembly language used in the IBM -1401 systems.   In spite of some additional advantage, assembly language has remained machine dependent and relatively difficult to use.

 

High level language:   A high level language is designed to be user friendly, enabling programmers to write instruction using a combination of words in English and in mathematical notations. The language is machine independent and hence the programs can be executed on different machines with very little change. Ex: COBOL, BASIC, FORTRAN, PASCAL, C

 

 

11. What is a hard disk? What are its features?

 

 

Hard disk is one of the storage devices, developed to store huge amount of data. The introduction of high capacity hard disks for micro computer system solved two serious problems related to the limited storage capacity of diskettes.   First, as a business begins to use micro computers extensively, the amount of software acquired and data collected tends to grow substantially. As a result the number of diskettes required, increases, dramatically second, the largest file that can be accessed at one time is limited to the capacity of the main memory and the storage medium.

 

A hard disk can store huge amount of data in a most convenient way.   In hard disk system, data is stored in the same way as it is on diskettes. A series of tracks are divided in to sectors when the disk is formatted. Hard disk is made out of a rigid substance that is capable of storing a greater amount of data than the soft material used for diskettes. The hard disk drives for the micro computer can be internal or external.   In a disk pack, the access mechanism can position itself to access data from each of the 200 cylinder is a set of all tracks with the same distance from the axis about which the disk pack rotates. In this example there are 10 tracks in each cylinder.   The capacity of diskettes in wide use today ranges from 360KB to 144MB each. Microsoft hard disk capacity ranges from 10MB to 1GB or higher. Hard disks larger capacity allows the user to store larger files and larger programs than can be used with diskettes. Access time with the hard disk is much lower than that of diskette i.e., data retrieval is much faster with the hard disk than a diskette.

 

Characteristics of a Hard disk:

 

1. They are rigid metal platters connected to a central spindle.

 

2. The entire disk unit is placed in a permanently sealed container.

 

3. Air that flow through the container is filtered to prevent contamination.

 

4. The disks are rotated at a very high speed (usually around 3600 RPM)

 

5. These disk drives can have four or more disk platters in a sealed unit.

 

6. In most of the disk units, the read/ write head does not touch the surface of the disk. Instead they are designed to float from 0.5 to 1.25 millionth of an inch from the disk surface. (Flying head design). Because the heads float so close to the sensitive disks, any contamination such as dust particle or hair, cause a head crash or a disk crash, which destroys some or all the data on the disk. Therefore hard disks are handled under sterile conditions.

 

7. Hard disk technology was introduced by IBM (1970) since then they have become the most necessary memory hungry software.

 

12. What are the advantages and disadvantages of computerization of business activities (electronic data processing)?

 

 

Advantages:

 

1. Speed: Computerization helps in processing the data placed in several data files in no time. This is possible due to the high speed of computers for processing data and CPU of the computer works at the speed of electricity which is the highest ever attainable speed.

 

2. Accuracy: The data processed by the computer are highly accurate. The programs written on the system checks and controls data before and during processing. It detects invalid data and ensures high degree of accuracy and reliability of output reports.

 

3. Flexibility: The modern digital computers can be used for a variety of purposes. E.g. online processing, multiprogramming etc.

 

4. Choice of Configuration: Wide ranges of peripherals are available for many computer systems, which allow business organization to select those which most suit its processing requirements.

 

5. Storage capacity: Large volumes of data can be conveniently stored, accessed and altered.

 

6. Management information: They can be used to provide useful information of management for control and decision making.

 

7. Data Processing: Computer has lifted the heavy data processing constraint with the manual system and has opened up new avenues for planning, control and data experimentation.

 

8. Volume: Computers can store volumes of data and can retrieve the desired information quickly. This is very useful in the areas like insurance, bank accounts etc where large number of documents is handled every day.

 

9. Database: Computer facilities the establishment of database. Such a database integrates data records and reduces data redundancy.

 

10.Reduction in paper work: The use of computers for data processing has helped the management of business organizations to cope with increasing problem of paper handling. The computers have speeded up the process and have eliminated the paper needs through the storage of data in elaborately constructed data bases and files.

 

11.Reduced cost: Though the initial investment for installing a computer is high, but it substantially reduces the cost of each of its transaction. Cost reduction occurs due to processing of huge data and record keeping.

 

12.Facilitates report preparation: Computer facilitates the preparation of various types of reports required by organizational executives for the purpose of decision making and control.

 

13.Reduce the space requirements: The use of computer for office activities reduces the requirements of office space which otherwise is required.

 

14.Reduces the manpower requirement: The number of persons required for performing various organizational activities will be reduced by using a computer system.

 

15.Increased ability to perform computations: Computers perform computations with a very high speed.   16.Diligence: Being a machine, it does not suffer from boredom, tiredness or lack of concentration, even if millions of computations are to be performed by a computer. It performs the calculations with same accuracy and speed.

 

Disadvantages:

 

1. Installing the computer requires a grueling and expensive task of system analysis and design. There is a scarcity of computer professionals to do this.

 

2. Management tends to treat computer like ordinary equipment Viz., air conditioning equipment, and keep themselves aloof from the system development effort. Computer pervades the working of the entire organization and unless managements involve themselves fully during the system development effort and the employees, the customers, the vendors etc. are willing to accept the computerized system and its outputs the system is bound to prove a failure.

 

3. The initial investment can be very high though this can be mitigated to some extent by the rental and tax concessions.

 

4. Since the lead-time of installing is long and the hardware technology is a rapidly advancing field, some of the peripherals/components may be rendered obsolete before even they are installed.

 

5. The need to obtain stand by facilities in the event of breakdown of any computerized systems. Manual systems, though slow, are vastly flexible. If the format of a report, for example has to be changed, it can be readily done by communicating the necessary instruction to the concerned staff whereas in a computerized system, this would have to go through all the stages of systems analysis and design before it is effected.