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Definition of digital computer, Elements of computer: Input unit, Output unit, Primary memory, Secondary memory and Processing unit.
- Computer is an electronic device that is designed to work with Information. term computer is derived from the Latin term‘computare’, this means to calculate or programmable machine. Computer cannot do anything without a Program. It represents the decimal numbers through a string of binary digits. The Word 'Computer' usually refers to the Center Processor Unit plus Internal memory.
- Charles Babbage is called the "Grand Father" of the computer. The First mechanical computer designed by Charles Babbage was called Analytical Engine. It uses read-only memory in the form of punch cards.
Digital Computer Definition
- The basic components of a modern digital computer are: Input Device, Output Device, Central Processor Unit (CPU), mass storage device and memory. A Typical modern computer uses LSI Chips.
Four Functions about computer are:
accepts data |
Input |
processes data |
Processing |
produces output |
Output |
stores results |
Storage |
Input (Data):
Input is the raw information entered into a computer from the input devices. It is the collection of letters, numbers, images etc.
Process:
Process is the operation of data as per given instruction. It is totally internal process of the computer system.
Output:
Output is the processed data given by computer after data processing. Output is also called as Result. We can save these results in the storage devices for the future use.
All general-purpose computers require the following hardware components:
Memory: enables a computer to store, at least temporarily, data and programs.
Mass storage device: allows a computer to permanently retain large amounts of data. Common mass storage devices include solid state drives (SSDs) or disk drives and tape drives.
Input device: usually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer.
Output device: a display screen, printer, or other device that lets you see what the computer has accomplished.
Central processing unit (CPU): the heart of the computer, this is the component that actually executes instructions.
In addition to these components, many others make it possible for the basic components to work together efficiently. For example, every computer requires a bus that transmits data from one part of the computer to another.
CPU (Processing Unit)
CPU (pronounced as separate letters) is the abbreviation for central processing unit. Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is the brains of the computer where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.
Components of a CPU
The two typical components of a CPU include the following:
The arithmetic logic unit (ALU), which performs arithmetic and logical operations.
The control unit (CU), which extracts instructions from memoryand decodes and executes them, calling on the ALU when necessary.
Relationship between the elements of the CPU, input and output, and storage
Printed Circuit Boards, Microprocessors
On large machines, the CPU requires one or more printed circuit boards. On personal computers and small workstations, the CPU is housed in a single chip called a microprocessor. Since the 1970's the microprocessor class of CPUs has almost completely overtaken all other CPU implementations.
The CPU itself is an internal component of the computer. Modern CPUs are small and square and contain multiple metallic connectors or pins on the underside. The CPU is inserted directly into a CPU socket, pin side down, on the motherboard.
Each motherboard will support only a specific type (or range) of CPU, so you must check the motherboard manufacturer's specifications before attempting to replace or upgrade a CPU in your computer. Modern CPUs also have an attached heat sink and small fan that go directly on top of the CPU to help dissipate heat.
MEMORY
Memory is major part of computers that categories into several types. Memory is best storage part to the computer users to save information, programs and etc, The computer memory offer several kinds of storage media some of them can store data temporarily and some them can store permanently. Memory consists of instructions and the data saved into computer through Central Processing Unit (CPU).
Types of Computer Memory:
Memory is the best essential element of a computer because computer can’t perform simple tasks. The performance of computer mainly based on memory and CPU. Memory is internal storage media of computer that has several names such as majorly categorized into two types, Main memory and Secondary memory.
1. Primary Memory / Volatile Memory.
2. Secondary Memory / Non Volatile Memory.
- Primary Memory / Volatile Memory:
Primary Memory also called as volatile memory because the memory can’t store the data permanently. Primary memory select any part of memory when user want to save the data in memory but that may not be store permanently on that location. It also has another name i.e. RAM.
Random Access Memory (RAM):
The primary storage is referred to as random access memory (RAM) due to the random selection of memory locations. It performs both read and write operations on memory. If power failures happened in systems during memory access then you will lose your data permanently. So, RAM is volatile memory. RAM categorized into following types.
DRAM
SRAM
DRDRAM
- Secondary Memory / Non Volatile Memory:
Secondary memory is external and permanent memory that is useful to store the external storage media such as floppy disk, magnetic disks, magnetic tapes and etc cache devices. Secondary memory deals with following types of components.
Read Only Memory (ROM) :
ROM is permanent memory location that offer huge types of standards to save data. But it work with read only operation. No data lose happen whenever power failure occur during the ROM memory work in computers.
ROM memory has several models such names are following.
1. PROM: Programmable Read Only Memory (PROM) maintains large storage media but can’t offer the erase features in ROM. This type of RO maintains PROM chips to write data once and read many. The programs or instructions designed in PROM can’t be erased by other programs.
2. EPROM : Erasable Programmable Read Only Memory designed for recover the problems of PROM and ROM. Users can delete the data of EPROM thorough pass on ultraviolet Light and it erases chip is reprogrammed.
3. EEPROM: Electrically Erasable Programmable Read Only Memory similar to the EPROM but it uses electrical beam for erase the data of ROM.
Cache Memory: Mina memory less than the access time of CPU so, the performance will decrease through less access time. Speed mismatch will decrease through maintain cache memory. Main memory can store huge amount of data but the cache memory normally kept small and low expensive cost. All types of external media like Magnetic disks, Magnetic drives and etc store in cache memory to provide quick access tools to the users.
,
A computer is an electronic device that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks.
Computers are used for a variety of purposes, including:
- Data processing. Computers can be used to store, organize, and manipulate data.
- Communication. Computers can be used to send and receive information over the Internet.
- Entertainment. Computers can be used to play games, watch Videos, and listen to music.
- Education. Computers can be used to learn new things, take classes, and get degrees.
- Business. Computers are used to manage finances, track inventory, and communicate with customers.
- Science. Computers are used to analyze data, simulate experiments, and design new products.
- Engineering. Computers are used to design and build structures, machines, and products.
- Medicine. Computers are used to diagnose diseases, prescribe medications, and perform surgery.
The basic components of a computer are:
- Central processing unit (CPU). The CPU is the brain of the computer. It is responsible for carrying out the instructions of the program.
- Random-access memory (RAM). RAM is a temporary storage area for data and programs. It is erased when the computer is turned off.
- Read-only memory (ROM). ROM is a permanent storage area for data and programs. It is not erased when the computer is turned off.
- Storage devices. Storage devices are used to store data permanently. They include hard drives, solid-state drives, and optical drives.
- Input/output (I/O) devices. I/O devices are used to input data into the computer and output data from the computer. They include keyboards, mice, monitors, printers, and scanners.
- Motherboard. The motherboard is the main circuit board in the computer. It houses the CPU, RAM, ROM, and other components.
- Graphics processing unit (GPU). The GPU is responsible for processing graphics. It is used in video games, 3D modeling, and other graphics-intensive applications.
- Power supply unit (PSU). The PSU provides power to the other components in the computer.
- Case. The case protects the internal components of the computer.
- Cooling system. The cooling system keeps the components of the computer from overheating.
- Network card. The network card allows the computer to connect to a network.
- Sound card. The sound card allows the computer to produce sound.
- Modem. The modem allows the computer to connect to the internet.
- Webcam. The webcam allows the computer to capture video.
- Scanner. The scanner allows the computer to digitize images.
- Printer. The printer allows the computer to print documents.
- Keyboard. The keyboard is used to input text into the computer.
- Mouse. The mouse is used to move the cursor on the screen and select items.
- Monitor. The monitor displays the output of the computer.
- Projector. The projector projects the output of the computer onto a screen.
- Headset. The headset allows the user to hear sound from the computer and speak into the microphone.
- Speakers. The speakers produce sound from the computer.
- Microphone. The microphone allows the user to speak into the computer.
- Touchscreen. The touchscreen allows the user to interact with the computer by touching the screen.
- Barcode reader. The barcode reader allows the computer to read barcodes.
- Fingerprint reader. The fingerprint reader allows the computer to authenticate users by their fingerprints.
- Card reader. The card reader allows the computer to read data from cards, such as credit cards and ID cards.
Computers are becoming increasingly complex and powerful. They are used in a wide variety of applications, from simple tasks such as word processing to complex tasks such as scientific research and engineering.
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Which of the following is not a type of computer?
(A) Desktop
(B) Laptop
(C) Smartphone
(D) Car -
Which of the following is not a component of a computer?
(A) CPU
(B) RAM
(C) Hard drive
(D) Car -
Which of the following is not a function of a computer?
(A) Processing data
(B) Storing data
(C) Retrieving data
(D) Driving a car -
Which of the following is not a unit of measurement for data?
(A) Bit
(B) Byte
(C) Kilobyte
(D) Car -
Which of the following is not a type of Software?
(A) Operating system
(B) Application software
(C) System software
(D) Car -
Which of the following is not a type of network?
(A) Local area network (LAN)
(B) Wide area network (WAN)
(C) Metropolitan area network (MAN)
(D) Car -
Which of the following is not a type of security threat?
(A) Virus
(B) Worm
(C) Trojan horse
(D) Car -
Which of the following is not a way to protect your computer from security threats?
(A) Use a firewall
(B) Keep your software up to date
(C) Use strong passwords
(D) Drive a car -
Which of the following is not a type of computer input device?
(A) Keyboard
(B) Mouse
(C) Scanner
(D) Car -
Which of the following is not a type of computer output device?
(A) Monitor
(B) Printer
(C) Speaker
(D) Car