Computer System
What is Computer System?
Computer is an electronic device that can be programmed to accept data (input), process it and generate result (output). A computer along with additional hardware and software together is called a computer system.
What are the basic units of computer system?
Basic units of a computer system are:
- Input Unit
- Central Processing Unit
(CPU)
- Primary Memroy
- Control Unit (CU)
- Arithmetic Logic Unit (ALU)
- Secondary Storage / Memory Unit
- Output Unit
What is Central Processing Unit (CPU)
Electronic circuitry of a computer that carries out the actual processing is known as Central Processing Unit. It is also known as processor or brain of the computer system. It is baiscally made up of three parts.
- Control Unit : CU controls sequential instruction execution, interprets instructions and guides data flow through the computer’s memory, ALU and input or output devices
- Arithmetic Logic Unit :ALU performs all the arithmetic and logic operations that need to be done as per the instruction in a program.
- Registers: CPU stores the data as well as instructions in its high speed local (temporary) memory while processing, this storage is called register.
What do you mean by input device? Name some common input device?
The devices through which control signals are sent to a computer are termed as input devices. These devices convert the input data into a digital form that is acceptable by the computer system. Some common input devices are Keyboard, Mouse, Scanner, MICR, OCR, Lignt Pen, Touch Pad, Joy Stick etc.
What is output device?
The device that receives data from a computer system for display, physical production, etc., is called output device. It converts digital information into humanunderstandable form. For example, monitor, projector, headphone, speaker, printer, etc.
Name any two command line inteface OS?
DOS (Disk Operting System) and UNIX are two Command Line Interface operating systems.
What is computer Memory?
Memory unit is the chip that is used to store data, instructions and programs. Memory unit is directly accessed by the CPU. Standard unit of memory is byte. 8bits form 1 byte. computer memory is classified as:
- Primary Memory : RAM, ROM, Cache Memory
- Secondary Memroy : Hard Disk, Tape Drive, Pen Drive, CD / DVD ROM
How we can classify a microporcessor?
Microprocessors are classified on the basis of different features which include chip type, word size, memory size, clock speed, number of cores.
Word Size: Word size is the maximum number of bits that a microprocessor can process at a time. It can be 8bits, 16bits, 32 bits and 64bits
Memory Size: Depending upon the word size, the size of RAM varies. As the word size increases, it need more memory.
Clock Speed: The clock speed indicates the speed at which the computer can execute instructions. It is measured in Kilo Hertz(KHz) or GigaHertz (GHz) i.e billions of pulses per second.
Cores: Core is a basic computation unit of the CPU. Earlier processors had only one computation unit, thereby perform only one task at a time. Now days we use multicore processor that execute multiple tasks, thereby increase the system’s performance. CPU with two, four, and eight cores is called dual-core, quad-core and octa-core processor, respectively.
What is Microcontroller?
Microcontroller is a small computing device which has a CPU, a fixed amount of RAM, ROM and other peripherals all embedded on a single chip. It is designed for specific tasks only, hence their size as well as cost is reduced. For example Microcontroller used in a Washing Machnine, Remote Controller, Micowave Oven etc.
Define the term Hardware and Software.
Hardware refers to the physical components of the computer system which can be seen and touched. For example, RAM, keyboard, printer, monitor, CPU, etc.
Software is a set of instructions and data that makes hardware functional to complete the desired task. Software can be classified as :
- System Software
- Language Processors and Operating System
- Application Software
Why we need software?
The sole purpose of a software is to make the computer hardware useful and operational. A software knows how to make different hardware components of a computer work and communicate with each other as well as with the end-user. We cannot instruct the hardware of a computer directly. Software acts as an interface between human users and the hardware. Software make the specific task easier and faster with great accuracy.
What is an operating system?
Operating system is a system software that acts as an interface between hardware and user. Operating system provides a platform to execute other software. Without operating system hardware will not be functional and no software executes. The operating system manages other application programs and provides access and security to the users of the system. Some of the popular operating systems are Windows, Linux, Macintosh, Ubuntu, Fedora, Android, iOS, etc.
Define the term system utilites and device drivers in context of software?
System Utilities: Software used for maintenance and configuration of the computer system is called system utility. Disk cleaning software, disk defragmentation program, anti virus software are example of system utilities.
Device Drivers: Device drivers are special programs that ensure proper functioning of a particular device. As everyday new device are developed and operating systems also updated, thus to maintain proper functioning updates are required in system software, that comes as device drivers. The device driver acts as an interface between the device and the operating system.
What does a bus mean?
A bus is a group of conducting lines that transport data, address and control signals between CPU and memory. Computer bus are of three types:
- Data Bus
- Address Bus
- Control Bus
What is the difference between RAM and ROM?
RAM refers to random access memory where both read and write operations can take place. RAM is a volatile memory; its contents are lost when power is turned off.
ROM refers to read-only memory where only read or write operation can take place. ROM is a non-volatile memory.
Both RAM and ROM are parts of the primary memory.
What is Unicode? How is it useful?
Unicode refers to Universal Coding Standard adopted by all platforms. A non-profit organization Unicode Consortium promotes it. Unicode provides a unique number for every character irrespective of the platform, program and language. It is a character coding system designed to support the worldwide interchange, processing and display of the written texts in multiple languages. A unique provides a code number for every character, no matter what the platform, no matter what the program, no matter what the language.
What are the functions of an operating system?
Operating system is an interface between the user and the computer and supervises the working of computer system, i.e., it monitors and controls the hardware and software of the computer system.
Some general functions of an operating system are:
Process Management: A task in execution is known as process. It is the responsibility of operating system to manage these processes and get multiple tasks completed in minimum time. As CPU is the main resource of computer system, its allocation among processes is the most important service of the operating system. Hence process management concerns the management of multiple processes, allocation of required resources, and exchange of information among processes.
Memory Management: Primary or main memory of a computer system is usually limited. Operating system manages memory management to give (allocate) and take (free) memory from running processes.
File Management: Data and programs are stored as files in the secondary storage of a computer system. File management involves the creation, updation, deletion and protection of these files in the secondary memory. Protection of data and files is also a crucial function of an operating system,
Device Management: A computer system has many I/O devices and hardware connected to it. Operating system manages these heterogeneous devices that are interdependent. The operating system interacts with the device driver and the related software for a particular device.
HOME WORK : DO YOURSELF
Home Work Questions :
1. Name the software required to make a computer functional. Write down its two primary services.
2. How does the computer understand a program written in high level language?
3. Why is the execution time of the machine code less than that of source code?
4. What is the need of RAM? How does it differ from ROM?
5. What is the need for secondary memory?
6. How do different components of the computer communicate with each other?
7. Drawthe block diagram of a computer system. Briefly write about the functionality of each component.
8. What is the primary role of system bus? Why is data bus is bidirectional while address bus is unidirectional?
9. Differentiate b ween proprietary software and freeware software. Name two software for each type.
10. Write the main difference between microcontroller and microprocessor.Why do smart home appliances have a microcontroller instead of microprocessor embedded in them?
11. Mention the different types of data that you deal with while browsing the Internet.
12. Categorise the following data as structured, semistructured and unstructured:
• Newspaper
• Cricket Match Score
• HTML Page
• Patient records in a hospital
13. Name the input or output device used to do the following:
- To output audio
- To enter textual data
- To make hard copy of a text file
- To display the data or information
- To enter audio-based command
- To build 3D models
- To assist a visually-impaired individual in entering data
14. Identify the category (system, application, programming tool) of the following software:
a) Compiler b) Assembler c) Ubuntu d) Text editor