The chapter introduces computer memory units including main memory (RAM) and secondary storage. It discusses different types of memory like RAM, ROM, PROM, and EPROM. RAM is volatile and used for temporary storage while ROM permanently stores basic instructions. Secondary storage devices discussed include magnetic tapes, floppy disks, and hard disks which store large amounts of non-volatile data. Optical disks like CDs, DVDs, and Blu-ray are also covered as high capacity, portable secondary storage.
The document provides information about various computer components. It discusses the CPU as the brain of the computer that issues commands. It also describes different types of memory including RAM, ROM, and flash drives. Expansion cards are discussed as used to expand computer capabilities, such as graphics cards, sound cards, and network cards. Storage devices include internal hard drives and external drives like external hard drives and flash drives. Input devices such as keyboards, mice, and touchscreens are used to input information. Output devices like printers, monitors, and speakers are used to output information from the computer.
General features of computer – Evolution of computers; Computer Applications – Data Processing – Information Processing – Commercial – Office Automation – Industry and Engineering – Healthcare – Education – Disruptive technologies.
The document provides information about different types of computers and their components. It discusses supercomputers, mainframes, minicomputers, personal computers, and other categories. It also describes the central processing unit (CPU), memory, storage devices, input/output devices, and other key parts. Specifications for comparing computers such as processor speed, memory size, storage capacity, and other metrics are outlined.
The document provides an overview of hardware components including the central processing unit, primary and secondary storage, and input/output devices. It discusses how the CPU fetches and executes instructions in four steps and how pipelining can improve processing speed. The document also covers memory types, characteristics of processing and storage devices, and different computer system types.
The document discusses the hierarchy of computer systems from supercomputers to microcomputers. It explains that supercomputers are the most powerful for processing large datasets. Mainframes are less powerful than supercomputers and are used for applications like banking. Midrange computers include minicomputers and servers. Microcomputers range from desktop PCs to mobile devices. The CPU and computer memory are also described.
Computer hardware includes various components that perform different functions like input, processing, output, and storage. The main components are the processor, memory, input devices, output devices, and storage devices. The processor fetches and executes instructions while memory temporarily stores data and programs. Common input devices are the keyboard and mouse, while output devices include monitors and printers. Frequent storage devices are hard drives, CDs/DVDs, USB drives, and memory cards.
Computer memory is divided into primary and secondary memory. Primary memory, like RAM, allows direct access by the CPU and is volatile. Secondary memory, like hard disks, is permanent but requires accessing through primary memory. RAM is temporary memory that stores active data and instructions, while ROM contains permanent, unalterable instructions for starting the computer. Secondary memory devices store data permanently and include hard disks, CDs, DVDs, USB drives, and cloud storage. Data is represented digitally using bits and bytes as basic units, with kilobytes, megabytes, and gigabytes as larger units to measure larger amounts of stored data.
The document provides information about various computer components. It discusses the CPU as the brain of the computer that issues commands. It also describes different types of memory including RAM, ROM, and flash drives. Expansion cards are discussed as used to expand computer capabilities, such as graphics cards, sound cards, and network cards. Storage devices include internal hard drives and external drives like external hard drives and flash drives. Input devices such as keyboards, mice, and touchscreens are used to input information. Output devices like printers, monitors, and speakers are used to output information from the computer.
General features of computer – Evolution of computers; Computer Applications – Data Processing – Information Processing – Commercial – Office Automation – Industry and Engineering – Healthcare – Education – Disruptive technologies.
The document provides information about different types of computers and their components. It discusses supercomputers, mainframes, minicomputers, personal computers, and other categories. It also describes the central processing unit (CPU), memory, storage devices, input/output devices, and other key parts. Specifications for comparing computers such as processor speed, memory size, storage capacity, and other metrics are outlined.
The document provides an overview of hardware components including the central processing unit, primary and secondary storage, and input/output devices. It discusses how the CPU fetches and executes instructions in four steps and how pipelining can improve processing speed. The document also covers memory types, characteristics of processing and storage devices, and different computer system types.
The document discusses the hierarchy of computer systems from supercomputers to microcomputers. It explains that supercomputers are the most powerful for processing large datasets. Mainframes are less powerful than supercomputers and are used for applications like banking. Midrange computers include minicomputers and servers. Microcomputers range from desktop PCs to mobile devices. The CPU and computer memory are also described.
Computer hardware includes various components that perform different functions like input, processing, output, and storage. The main components are the processor, memory, input devices, output devices, and storage devices. The processor fetches and executes instructions while memory temporarily stores data and programs. Common input devices are the keyboard and mouse, while output devices include monitors and printers. Frequent storage devices are hard drives, CDs/DVDs, USB drives, and memory cards.
Computer memory is divided into primary and secondary memory. Primary memory, like RAM, allows direct access by the CPU and is volatile. Secondary memory, like hard disks, is permanent but requires accessing through primary memory. RAM is temporary memory that stores active data and instructions, while ROM contains permanent, unalterable instructions for starting the computer. Secondary memory devices store data permanently and include hard disks, CDs, DVDs, USB drives, and cloud storage. Data is represented digitally using bits and bytes as basic units, with kilobytes, megabytes, and gigabytes as larger units to measure larger amounts of stored data.
Computer hardware consists of the physical and tangible components that make up a computer system. The main hardware components include input devices like keyboards and mice, output devices like monitors and printers, the central processing unit (CPU), storage devices like hard disks and CDs/DVDs, memory components like RAM and ROM, and other essential pieces like the motherboard, power supply, and cooling fans. Together, these hardware components work together to process and store digital information.
Hardware refers to the physical components of a computer including input devices, output devices, storage devices, and the central processing unit (CPU). The CPU consists of the arithmetic/logic unit (ALU) which performs calculations, the control unit which coordinates data flow, and register storage areas. Memory and storage devices such as RAM, ROM, magnetic disks, tapes, and solid state drives are used to store instructions and data with capacities measured in bytes, kilobytes, megabytes, and larger units. Input devices allow entering data and instructions while output devices such as monitors, printers, and speakers allow viewing and sharing the computer's output.
C language computer introduction to the computer hardwareNIKHIL KRISHNA
This document provides an overview of computer hardware, software, organization and concepts. It defines a computer as a device that performs computations and logical decisions by processing data under instruction sets. Key components include the central processing unit (CPU), memory, storage, input/output devices, and software like operating systems and applications. Fundamental concepts discussed include Moore's Law, which predicts an exponential increase in component density, Von Neumann architecture, and how memory is organized into addressable cells.
The document defines a computer and describes its basic components and functions. It states that a computer is an electronic device that processes data according to programmed instructions. It then explains the main functions of a computer as input, output, processing, and storage of data. The document proceeds to describe common input devices like keyboards, mice, and scanners. It also details processing devices such as CPUs and storage devices including hard drives, CDs, and memory sticks. Output devices such as monitors, printers, and headphones are also outlined. The document concludes by defining types of computers and networks, transmission media, and major internal computer parts.
The document provides an overview of key concepts related to computer systems, including:
- Hardware components like the CPU, memory, storage devices, and input/output devices and how they interact.
- How digital information is represented and stored using binary numbers.
- Different types of memory like RAM, ROM, and their characteristics.
- Storage media like hard disks, CDs, DVDs and their storage capacities.
- Basic concepts of networks, local area networks, and wide area networks.
- How the Internet developed from ARPANET and became a global network connecting many networks worldwide.
This document discusses different types of computer storage devices. It begins with a brief history of storage technologies like punch cards and magnetic tape. It then categorizes storage devices as either primary or secondary. Primary storage includes RAM and ROM, while secondary storage includes hard disks, CDs, DVDs, and other removable media. The document focuses on hard disks, describing their components like platters, arms, heads, and how data is stored in tracks and sectors. Other modern storage discussed includes diskettes, flash memory cards, and USB devices.
This document discusses different types of computer memory. It describes primary memory, which includes RAM that temporarily stores the operating system, and ROM with instructions from the manufacturer. RAM is volatile while ROM is read-only. ROM types are PROM and EPROM. Secondary memory includes hard disks for long-term storage, as well as external hard disks and CDs, which allow storing large amounts of data beyond what primary memory can hold. Secondary storage devices are used to save files when the computer is turned off.
Computers – A Gateway to Information(Memory)Tallat Satti
Memory consists of electronic components that store instructions, data, and processing results. It comes in two types - primary and secondary memory. Primary memory (RAM) is directly accessible by the CPU and is volatile, while secondary memory (hard disks, USB drives, etc.) provides non-volatile but slower storage. The memory hierarchy balances speed, space, and cost, with primary memory being faster but more expensive and limited than secondary memory.
This document provides an introduction to computers, including their components, functions, and types. It discusses hardware such as the CPU, memory (both primary and secondary), input/output devices, and storage. It also covers software types including system software, utility software, and application software. Finally, it briefly outlines computer generations and types including desktops, laptops, and embedded systems.
A motherboard is the main circuit board that holds and connects all the components of a computer system. It contains the CPU socket, memory slots, expansion slots, connectors for peripherals and power supply. Key components include the northbridge and southbridge chips, BIOS chip, and connectors for devices like graphics cards, hard drives, and expansion cards.
Computer hardware refers to the physical components of a computer and includes peripheral devices like printers, which reproduce text and graphics on paper, floppy disk drives, which read data from magnetic floppy disks, scanners, which convert printed materials into digital images, and CD-ROM drives, which allow users to play audio and video CDs. The central processing unit or CPU is an electronic circuit that executes computer programs.
This document provides an overview of different storage devices and their key components. It discusses floppy disk drives, hard disk drives, solid state drives, optical drives like CDs, DVDs, and Blu-Ray. For hard disk drives, it describes the platters, read/write heads, actuator assembly, spindle motor, connectors, jumpers, logic board, integrated cache, and disk geometry including heads, cylinders, sectors per track, and write precompensation. It also discusses different hard disk interface types like PATA, SATA, SCSI, and identifies their data buses.
1. The document discusses different types of computers including analog computers, digital computers, and hybrid computers. It also covers super computers, mini computers, and micro computers.
2. It then provides details on key components of computers such as input and output devices, the central processing unit (CPU), data storage devices, computer memory, graphic user interfaces, video cards, ports and peripherals, and resolution.
3. The document concludes by discussing local and wide area networks (LANs and WANs), bandwidth and baud rate, multitasking and multiprocessing, multimedia, file management, and an introduction to computer networks including their need and how they enhance communication.
The Basic Configuration of a Microcomputer Taminul Islam
A microcomputer consists of a microprocessor as the central processing unit, memory, and input/output devices. The microprocessor contains an arithmetic logic unit to perform calculations and logic operations. Memory is used to store programs and data and comes in primary forms like RAM and ROM, as well as secondary storage like hard disks. Common input devices include keyboards and output devices include monitors. Examples of microcomputers include desktops, laptops, tablets, and smartphones.
Computer hardware includes physical components like the case, monitor, keyboard, and mouse. It also includes internal components like the motherboard, CPU, RAM, hard drive, and power supply. Hardware is anything that can be physically touched. Basic concepts of hardware include input and output devices, as well as components like RAM, the keyboard, mouse, motherboard, hard drive, monitor, and USB flash drives. The CPU carries out computer programs by performing arithmetic, logical, and I/O operations.
The document discusses computer hardware components and technologies. It covers the central processing unit, computer memory, the evolution of hardware from vacuum tubes to integrated circuits, the hierarchy of computer systems, input/output devices, and trends like improving cost-performance of chips and emerging technologies like sensor webs and nanotechnology. The objectives are to describe hardware components, memory types, hardware evolution, and strategic issues related to keeping up with advancing technologies.
The document summarizes the five main units of a computer system: input, output, storage, arithmetic, and control units. It describes the functions of hardware components like integrated circuits, memory (RAM and ROM), and the processor. The processor has a control unit that retrieves and decodes instructions from memory and an arithmetic logic unit that performs calculations. Instructions are fetched, decoded, executed, and retired in sequence using the von Neumann architecture.
This document provides an overview of hardware and systems technology, covering topics like computers, input/output devices, data storage, communication devices, networks, and more. It defines key computer components and terms, describes common data types and file formats, explains how data is processed and transmitted, and outlines computer system organization from the CPU up through local and wide area networks. The document is intended to cover 15% of the content on an upcoming exam.
Computer Introduction-Lecture02 for applied scince college students, Seiyun University , yemen 2023-2024 Academic year. لطلاب كلية العلوم التطبيقية بجامعة سيئون
مقدمة في علوم الحاسوب المحاضرة الثانية
PERFORM CALCULATION AND MENSURATION.pptxEchelleOgatis
This document defines terms related to computer hardware components and their measurement. It discusses units of measurement like bits and bytes. It also defines common components like hard drives, memory, CPUs and their functions. The document provides definitions for ROM, RAM and cache memory. It explains different types of storage drives like hard drives, optical drives and flash drives. It concludes by describing common drive interfaces like IDE, SATA and SCSI.
Computer hardware consists of the physical and tangible components that make up a computer system. The main hardware components include input devices like keyboards and mice, output devices like monitors and printers, the central processing unit (CPU), storage devices like hard disks and CDs/DVDs, memory components like RAM and ROM, and other essential pieces like the motherboard, power supply, and cooling fans. Together, these hardware components work together to process and store digital information.
Hardware refers to the physical components of a computer including input devices, output devices, storage devices, and the central processing unit (CPU). The CPU consists of the arithmetic/logic unit (ALU) which performs calculations, the control unit which coordinates data flow, and register storage areas. Memory and storage devices such as RAM, ROM, magnetic disks, tapes, and solid state drives are used to store instructions and data with capacities measured in bytes, kilobytes, megabytes, and larger units. Input devices allow entering data and instructions while output devices such as monitors, printers, and speakers allow viewing and sharing the computer's output.
C language computer introduction to the computer hardwareNIKHIL KRISHNA
This document provides an overview of computer hardware, software, organization and concepts. It defines a computer as a device that performs computations and logical decisions by processing data under instruction sets. Key components include the central processing unit (CPU), memory, storage, input/output devices, and software like operating systems and applications. Fundamental concepts discussed include Moore's Law, which predicts an exponential increase in component density, Von Neumann architecture, and how memory is organized into addressable cells.
The document defines a computer and describes its basic components and functions. It states that a computer is an electronic device that processes data according to programmed instructions. It then explains the main functions of a computer as input, output, processing, and storage of data. The document proceeds to describe common input devices like keyboards, mice, and scanners. It also details processing devices such as CPUs and storage devices including hard drives, CDs, and memory sticks. Output devices such as monitors, printers, and headphones are also outlined. The document concludes by defining types of computers and networks, transmission media, and major internal computer parts.
The document provides an overview of key concepts related to computer systems, including:
- Hardware components like the CPU, memory, storage devices, and input/output devices and how they interact.
- How digital information is represented and stored using binary numbers.
- Different types of memory like RAM, ROM, and their characteristics.
- Storage media like hard disks, CDs, DVDs and their storage capacities.
- Basic concepts of networks, local area networks, and wide area networks.
- How the Internet developed from ARPANET and became a global network connecting many networks worldwide.
This document discusses different types of computer storage devices. It begins with a brief history of storage technologies like punch cards and magnetic tape. It then categorizes storage devices as either primary or secondary. Primary storage includes RAM and ROM, while secondary storage includes hard disks, CDs, DVDs, and other removable media. The document focuses on hard disks, describing their components like platters, arms, heads, and how data is stored in tracks and sectors. Other modern storage discussed includes diskettes, flash memory cards, and USB devices.
This document discusses different types of computer memory. It describes primary memory, which includes RAM that temporarily stores the operating system, and ROM with instructions from the manufacturer. RAM is volatile while ROM is read-only. ROM types are PROM and EPROM. Secondary memory includes hard disks for long-term storage, as well as external hard disks and CDs, which allow storing large amounts of data beyond what primary memory can hold. Secondary storage devices are used to save files when the computer is turned off.
Computers – A Gateway to Information(Memory)Tallat Satti
Memory consists of electronic components that store instructions, data, and processing results. It comes in two types - primary and secondary memory. Primary memory (RAM) is directly accessible by the CPU and is volatile, while secondary memory (hard disks, USB drives, etc.) provides non-volatile but slower storage. The memory hierarchy balances speed, space, and cost, with primary memory being faster but more expensive and limited than secondary memory.
This document provides an introduction to computers, including their components, functions, and types. It discusses hardware such as the CPU, memory (both primary and secondary), input/output devices, and storage. It also covers software types including system software, utility software, and application software. Finally, it briefly outlines computer generations and types including desktops, laptops, and embedded systems.
A motherboard is the main circuit board that holds and connects all the components of a computer system. It contains the CPU socket, memory slots, expansion slots, connectors for peripherals and power supply. Key components include the northbridge and southbridge chips, BIOS chip, and connectors for devices like graphics cards, hard drives, and expansion cards.
Computer hardware refers to the physical components of a computer and includes peripheral devices like printers, which reproduce text and graphics on paper, floppy disk drives, which read data from magnetic floppy disks, scanners, which convert printed materials into digital images, and CD-ROM drives, which allow users to play audio and video CDs. The central processing unit or CPU is an electronic circuit that executes computer programs.
This document provides an overview of different storage devices and their key components. It discusses floppy disk drives, hard disk drives, solid state drives, optical drives like CDs, DVDs, and Blu-Ray. For hard disk drives, it describes the platters, read/write heads, actuator assembly, spindle motor, connectors, jumpers, logic board, integrated cache, and disk geometry including heads, cylinders, sectors per track, and write precompensation. It also discusses different hard disk interface types like PATA, SATA, SCSI, and identifies their data buses.
1. The document discusses different types of computers including analog computers, digital computers, and hybrid computers. It also covers super computers, mini computers, and micro computers.
2. It then provides details on key components of computers such as input and output devices, the central processing unit (CPU), data storage devices, computer memory, graphic user interfaces, video cards, ports and peripherals, and resolution.
3. The document concludes by discussing local and wide area networks (LANs and WANs), bandwidth and baud rate, multitasking and multiprocessing, multimedia, file management, and an introduction to computer networks including their need and how they enhance communication.
The Basic Configuration of a Microcomputer Taminul Islam
A microcomputer consists of a microprocessor as the central processing unit, memory, and input/output devices. The microprocessor contains an arithmetic logic unit to perform calculations and logic operations. Memory is used to store programs and data and comes in primary forms like RAM and ROM, as well as secondary storage like hard disks. Common input devices include keyboards and output devices include monitors. Examples of microcomputers include desktops, laptops, tablets, and smartphones.
Computer hardware includes physical components like the case, monitor, keyboard, and mouse. It also includes internal components like the motherboard, CPU, RAM, hard drive, and power supply. Hardware is anything that can be physically touched. Basic concepts of hardware include input and output devices, as well as components like RAM, the keyboard, mouse, motherboard, hard drive, monitor, and USB flash drives. The CPU carries out computer programs by performing arithmetic, logical, and I/O operations.
The document discusses computer hardware components and technologies. It covers the central processing unit, computer memory, the evolution of hardware from vacuum tubes to integrated circuits, the hierarchy of computer systems, input/output devices, and trends like improving cost-performance of chips and emerging technologies like sensor webs and nanotechnology. The objectives are to describe hardware components, memory types, hardware evolution, and strategic issues related to keeping up with advancing technologies.
The document summarizes the five main units of a computer system: input, output, storage, arithmetic, and control units. It describes the functions of hardware components like integrated circuits, memory (RAM and ROM), and the processor. The processor has a control unit that retrieves and decodes instructions from memory and an arithmetic logic unit that performs calculations. Instructions are fetched, decoded, executed, and retired in sequence using the von Neumann architecture.
This document provides an overview of hardware and systems technology, covering topics like computers, input/output devices, data storage, communication devices, networks, and more. It defines key computer components and terms, describes common data types and file formats, explains how data is processed and transmitted, and outlines computer system organization from the CPU up through local and wide area networks. The document is intended to cover 15% of the content on an upcoming exam.
Computer Introduction-Lecture02 for applied scince college students, Seiyun University , yemen 2023-2024 Academic year. لطلاب كلية العلوم التطبيقية بجامعة سيئون
مقدمة في علوم الحاسوب المحاضرة الثانية
PERFORM CALCULATION AND MENSURATION.pptxEchelleOgatis
This document defines terms related to computer hardware components and their measurement. It discusses units of measurement like bits and bytes. It also defines common components like hard drives, memory, CPUs and their functions. The document provides definitions for ROM, RAM and cache memory. It explains different types of storage drives like hard drives, optical drives and flash drives. It concludes by describing common drive interfaces like IDE, SATA and SCSI.
This document discusses different types of computer memory. It describes main memory, which temporarily stores data and programs for direct CPU access. Main memory types include RAM, ROM, cache, and registers. Secondary memory stores much larger amounts of data for extended periods and includes hard disks, floppy disks, magnetic tapes, and optical disks. Important secondary storage methods are also outlined.
This document discusses the classification and hierarchy of memory systems in computers. It begins by explaining that computers utilize a memory hierarchy to efficiently store and access programs and data, since not all information is needed by the CPU at once. The hierarchy includes register sets, cache memory, main memory (RAM and ROM), hard disks, magnetic disks, and magnetic tapes, which differ in access time, transfer rate, and capacity. Faster but smaller and more expensive memory like registers are at the top, while larger but slower memory like hard disks are at the bottom. Understanding this memory hierarchy is important for knowing how computers access and manage programs and data.
This document discusses computer memory and storage. It defines primary and secondary memory, and describes their key differences. Primary memory, also called main memory, is volatile and used for processing. It has high access speeds but limited capacity. Secondary memory is non-volatile and used for long-term storage of large volumes of data. Common types of primary memory include RAM, ROM, and cache. Common forms of secondary memory include hard disks, optical disks, magnetic tapes, USB drives, and cloud storage. The document evaluates various storage media and provides details on their characteristics like capacity, access times, and usage.
Computer hardware refers to the physical components that make up a computer system. It includes processing components like the CPU and memory, as well as input devices, output devices, and storage devices. The CPU fetches and executes instructions from memory. Memory comes in different types, including cache memory, RAM, and ROM. Input devices like keyboards and mice allow entering data. Output devices like monitors and printers display or print the output. Storage devices such as hard drives and optical discs store data for later use.
This document discusses different types of computer memory organization. It describes main memory, which includes ROM, RAM, PROM, EPROM, and EEPROM. ROM is used for storing permanent programs and data. RAM is used for storing user programs and data temporarily. PROM, EPROM, and EEPROM can be programmed but EPROM and EEPROM can also be erased. Secondary storage includes magnetic tapes, floppy disks, hard disks, optical disks, and RAM disks. Floppy disks and hard disks provide faster and direct access compared to tapes but hard disks provide much higher storage capacity than floppy disks. Optical disks have high storage capacity but data cannot be erased.
Memory is essential for computers and comes in three main types: primary, cache, and secondary. Primary memory (RAM) is directly accessible by the CPU and comes in volatile forms like DRAM and SRAM. Cache memory improves access speed and can be L1/L2 caches. Secondary memory (hard disks, DVDs) provides large storage but is slower to access. The document discusses these memory types in detail along with their technologies and principles.
Computer storage holds data and programs that can be accessed by the processor. There are two types of storage: primary and secondary. Primary storage, like RAM and ROM, is internal memory that can be directly accessed by the CPU. Secondary storage is external and includes magnetic, optical, and flash memory used to store data long-term. RAM is volatile and used for temporary storage while processing, and ROM is non-volatile and stores permanent programs installed by the manufacturer. Secondary storage has greater capacity and lower cost per megabyte than primary storage and allows for portable storage of data.
This document discusses different types of computer storage. It describes primary memory (RAM), cache memory, and secondary memory. Primary memory is volatile and holds data currently being processed, while secondary memory (hard disks, USB drives, etc.) is non-volatile and used for long-term storage. Cache memory sits between the CPU and primary memory to provide faster access to frequently used data. The document also outlines different storage devices like hard disks, optical disks, USB drives and their characteristics.
Computer memory temporarily stores data and instructions for processing by the CPU. Primary memory (RAM and ROM) allows direct CPU access but loses data when powered off, while secondary memory (hard disks, USB drives, etc.) permanently stores data but requires copying to primary memory for CPU access. Primary memory is volatile and internal, while secondary memory is non-volatile and external. Together they provide data storage and retrieval capabilities essential for computer functioning.
The document discusses different types of computer memory. It describes memory as the component that stores information and data. There are two main types of memory: primary and secondary. Primary memory, such as RAM, temporarily stores data during processing while secondary memory, like hard disks, permanently stores data. The document provides examples of different primary memories including RAM, ROM, and different types of each. It also lists common secondary memory storage devices like hard disks, CDs, DVDs, and USB drives.
This document discusses different types of computer memory. It describes main memory, which is used for immediate access by the CPU, and secondary memory, which stores much larger amounts of data for longer periods. The main types of main memory are RAM, ROM, cache, and registers. RAM and ROM are further divided into static, dynamic, programmable, erasable, and electronically erasable types. Secondary memory includes magnetic disks, tapes, CD-ROMs, and solid-state storage. Hard disks can be internal, removable cartridges, or disk packs.
The document summarizes the key internal and external components of a computer system. It describes the motherboard as the main circuit board that holds the CPU and connects all other components. The CPU processes instructions using RAM for temporary storage and ROM for permanent storage of startup instructions. Other components described are hard drives for long-term storage, expansion cards for additional functions, power supply for electricity, and input/output ports and drives for connecting to other devices and media.
The document discusses the components and functioning of a computer system. It describes how a computer accepts data as input, processes it using the central processing unit (CPU) and other components, and produces output. The CPU contains a control unit and arithmetic logic unit (ALU) that work together to control data flow and perform calculations. The computer also includes storage devices like RAM, ROM, hard disks, and optical drives to permanently save data and programs.
This document provides an overview of computer storage fundamentals, including primary and secondary storage. It discusses the characteristics and uses of different types of primary storage (RAM and ROM) and secondary storage devices (floppy disks, hard disks, optical disks, USB flash drives, and magnetic tapes). RAM is temporary and volatile, holding data currently being processed, while ROM is permanent and non-volatile. Secondary storage devices are used to permanently store large amounts of non-essential data and include magnetic and optical media with varying speeds and capacities.
Computer memory is any physical device capable of storing information temporarily, like RAM (random access memory), or permanently, like ROM (read-only memory).
Memory devices utilize integrated circuits and are used by operating systems, software, and hardware.
Computer is an electronic device that accepts data as input, processes it, and provides results as output. It has three main components: the arithmetic logical unit (ALU) that performs calculations, the control unit (CU) that directs operations, and the central processing unit (CPU) that comprises the ALU and CU. Computers store data temporarily in RAM and permanently in various storage devices like hard disks, tapes, optical disks, and flash drives. They have evolved through five generations from vacuum tubes to today's integrated circuits and microprocessors. Computers come in various sizes ranging from supercomputers to desktops, laptops, and palmtop computers. They accept input through devices like keyboards and provide output through monitors and printers.
The document discusses the differences between computer memory and storage. Memory, such as RAM, is volatile and temporarily stores active data and programs, while storage, like a hard disk, is non-volatile and retains data even when powered off. Various types of primary storage devices including RAM and ROM are described. Secondary storage devices like hard disks, floppy disks, magnetic tapes, CDs, DVDs, and flash memory are also outlined along with their uses, advantages, and applications.
1. Chapter 8
Memory Units
Contents:
I. Introduction
• Basic units of Measurement
II. RAM,ROM,PROM,EPROM
• Storage versus Memory
III. Auxiliary Storage Devices-Magnetic Tape, Hard Disk, Floppy Disk
IV.Optical Disks: CD-R Drive, CD-RW disks, DVD, Blue ray Discs
-----------------------------------------------------------------------------------------
--
I. Introduction
The computer system essentially comprises three important parts – input device,
central processing unit (CPU) and the output device. The CPU itself is made of three
components namely, the arithmetic logic unit (ALU), memory unit, and the control
unit.
In addition to these, auxiliary storage/secondary storage devices are used to store data
and instructions on a long-term basis.
Central Processing Unit
Arithmetic
Logic Unit
Input Unit Output Unit
Control Unit
Main
Memory
Secondary
Storage
Figure 1 : Schematic Representation of a Computer
The objective of this chapter is to introduce the concept of Memory units of the
computer which are shown in the above figure as main memory and secondary
memory. The Memory unit is linked with other parts of the computer specifically as
shown in the figure2.
1
2. Figure 2: Linking Memory with other units
All storage devices are characterized with the following features:
• Speed
• Volatility
• Access method
• Portability
• Cost and capacity
1.1 Basic Units of Measurement
All information in the computer is handled using electrical components like the
integrated circuits, semiconductors, all of which can recognize only two states –
presence or absence of an electrical signal. Two symbols used to represent these two
states are 0 and 1, and are known as BITS (an abbreviation for BInary DigiTS). 0
represents the absence of a signal, 1 represents the presence of a signal. A BIT is,
therefore, the smallest unit of data in a computer and can either store a 0 or 1.
Since a single bit can store only one of the two values, there can possibly be only four
unique combinations:
00 01 10 11
Bits are, therefore, combined together into larger units in order to hold greater range
of values.
BYTES are typically a sequence of eight bits put together to create a single computer
alphabetical or numerical character. More often referred to in larger multiples, bytes
may appear as Kilobytes (1,024 bytes), Megabytes (1,048,576 bytes), GigaBytes
(1,073,741,824), TeraBytes (approx. 1,099,511,000,000 bytes), or PetaBytes
(approx. 1,125,899,900,000,000 bytes).
Bytes are used to quantify the amount of data digitally stored (on disks, tapes) or
transmitted (over the internet), and are also used to measure the memory and
document size.
II. RAM,ROM,PROM,EPROM
The Term Computer Memory is defined as one or more sets of chips that store
Data/program instructions, either temporarily or permanently. It is critical processing
2
3. component in any computer. The PCs use several different types. They are :
• Main Memory / Primary Memory units
– Two most important are
• RAM(Random Access Memory)
• ROM(Read-only Memory)
– They work in different ways and perform distinct functions
– CPU Registers
– Cache Memory
• Secondary Memory/Auxiliary Memory
Also termed as ‘auxiliary’ or ‘backup’ storage, it is typically used as a
supplement to main storage. It is much cheaper than the main storage and
stores large amount of data and instructions permanently. Hardware devices
like magnetic tapes and disks fall under this category.
Computer’s memory can be classified into two types – RAM and ROM.
RAM or Random Access Memory is the central storage unit in a computer system. It
is the place in a computer where the operating system, application programs and the
data in current use are kept temporarily so that they can be accessed by the
computer’s processor. The more RAM a computer has, the more data a computer can
manipulate.
Random access memory, also called the Read/Write memory, is the temporary
memory of a computer. It is said to be ‘volatile’ since its contents are accessible only
as long as the computer is on. The contents of RAM are cleared once the computer is
turned off.
ROM or Read Only Memory is a special type of memory which can only be read and
contents of which are not lost even when the computer is switched off. It typically
contains manufacturer’s instructions. Among other things, ROM also stores an initial
program called the ‘bootstrap loader’ whose function is to start the computer software
operating, once the power is turned on.
Read-only memories can be manufacturer-programmed or user-programmed.
While manufacturer-programmed ROMs have data burnt into the circuitry, user-
programmed ROMs can have the user load and then store read-only programs. PROM
or Programmable ROM is the name given to such ROMs.
Information once stored on the ROM or PROM chip cannot be altered. However,
another type of memory called EPROM (Erasable PROM) allows a user to erase the
information stored on the chip and reprogram it with new information. EEPROM
(Electrically EPROM) and UVEPROM (Ultra Violet EPROM) are two types of
EPROM’s.
Storage Vs. Memory
RAM is volatile memory having a limited storage capacity. Secondary/auxiliary
storage is storage other than the RAM. These include devices that are peripheral and
are connected and controlled by the computer to enable permanent storage of
programs and data.
Magnetic medium was found to be fairly inexpensive and long lasting medium and,
therefore, became the preferred choice for auxiliary storage. Floppy disks and hard
disks fall under this category. The newer forms of storage devices are optical storage
3
4. devices like CDs, DVDs, Pen drive, Zip drive etc.
To Summaries:
The memory is specifically meaning the RAM. This keeps the information for a
shorter period of time (usually volatile), is faster and more expensive.
By Storage we mean the Hard disk. Here the information is retained longer (non-
volatile),It’s Slower and Cheaper
III. Auxiliary Storage Devices-Magnetic Tape, Floppy Disk, Hard Disk.
The Magnetic Storage Exploits duality of magnetism and electricity. It converts
electrical signals into magnetic charges, captures magnetic charge on a storage
medium and then later regenerates electrical current from stored magnetic charge.
Polarity of magnetic charge represents bit values zero and one.
Magnetic Disk
The Magnetic Disk is Flat, circular platter with metallic coating that is rotated beneath
read/write heads. It is a Random access device; read/write head can be moved to any
location on the platter.
Floppy Disk
These are small removable disks that are plastic coated with magnetic recording
material. Floppy disks are typically 3.5″ in size (diameter) and can hold 1.44 MB of
data. This portable storage device is a rewritable media and can be reused a number of
times.
Floppy disks are commonly used to move files between different computers. The
main disadvantage of floppy disks is that they can be damaged easily and, therefore,
are not very reliable. The following figure shows an example of the floppy disk.
Figure 3 shows a picture of the floppy disk.
Figure 3: Floppy Disk
HARD DISK
Another form of auxiliary storage is a hard disk. A hard disk consists of one or
more rigid metal plates coated with a metal oxide material that allows data to be
magnetically recorded on the surface of the platters. The hard disk platters spin at
4
5. a high rate of speed, typically 5400 to 7200 revolutions per minute (RPM).Storage
capacities of hard disks for personal computers range from 10 GB to 120 GB (one
billion bytes are called a gigabyte).
Figure 4: Hard Disk
IV.Optical Disks: CD-R Drive, CD-RW disks, DVD, Blue ray Discs
Optical Mass Storage Devices Store bit values as variations in light reflection. They
have higher area density & longer data life than magnetic storage. They are also
Standardized and relatively inexpensive. Their Uses: read-only storage with low
performance requirements, applications with high capacity requirements & where
portability in a standardized format is needed.
Example of the Optical Drives
• CD's (Compact Disk)
Their storage:
~ 700 MB storage
Their Types:
– CD-ROM (read only)
– CD-R: (record) to a CD
– CD-RW: can write and erase CD to reuse it (re-writable)
– DVD(Digital Video Disk)
CD:
Compact Disk (CD) is portable disk having data storage capacity between 650-700
MB. It can hold large amount of information such as music,
full-motion videos, and text etc. It contains digital information that can be read, but
cannot be rewritten. Separate drives exist for reading and writing CDs.
Since it is a very reliable storage media, it is very often used as a medium for
distributing large amount of information to large number of users. In fact today most
of the software is distributed through CDs.
DVD
Digital Versatile Disk (DVD) is similar to a CD but has larger storage capacity and
enormous clarity. Depending upon the disk type it can store several Gigabytes of data
(as opposed to around 650MB of a CD). DVDs are primarily used to store music or
5
6. movies and can be played back on your television or the computer too. They are not
rewritable media. Its also termed DVD (Digital Video Disk)
DVD-ROM
– Over 4 GB storage (varies with format)
– DVD- ROM (read only)
– Many recordable formats (e.g., DVD-R, DVD-RW; ..)
– Are more highly compact than a CD.
– Special laser is needed to read them
Blu-ray Technology
The name is derived from the blue-violet laser used to read and write data. It was
developed by the Blu-ray Disc Association with more than 180 members. Some
companies with the technology are Dell, Sony, LG.The Data capacity is very large
because Blu-ray uses a blue laser(405 nanometers) instead of a red laser(650
nanometers) this allows the data tracks on the disc to be very compact. This allows for
more than twice as small pits as on a DVD. Because of the greatly compact data Blu-
ray can hold almost 5 times more data than a single layer DVD. Close to 25 GB!.Just
like a DVD Blu-ray can also be recorded in Dual-Layer format. This allows the disk
to hold up to 50 GB!!
The Variations in the formats are as follows:
• BD-ROM (read-only) - for pre-recorded content
• BD-R (recordable) - for PC data storage
• BD-RW (rewritable) - for PC data storage
• BD-RE (rewritable) - for HDTV recording
Summary:
The chapter has introduced the concept of memory units and its categories as the main
and the second memory and their characteristic features. It discusses the features of
RAM, ROM, PROM, and EPROM. Auxiliary Storage Devices like -Magnetic Tape,
Hard Disk, Floppy Disk are also discussed .The chapter concludes with an
introduction to the Optical Disks such as CD-R Drive,CD-RW disks,DVD,Blue ray
Discs
6