Computer Fundamentals Lecture 5&6 PDF

Computer Fundamentals Dr Mohammed Kayed 04 Computer Hardware - Part II Discussing Input and Output devises. Also, discussing Memory Unit as well.  Table of contents 01 02...

Computer Fundamentals Dr Mohammed Kayed 04 Computer Hardware - Part II Discussing Input and Output devises. Also, discussing Memory Unit as well.  Table of contents 01 02 03 Introduction Number Systems Hardware A breif introduction to Numbering systems and Details about computer computers and their use conversions from one HARDWARE in our Society system to another  Table of contents 04 05 06 Software Networks Security Details about computer An introduction to An introduction to SOFTWARE computer Networks and computer Security the Internet  Memory Unit Memory units are the storage areas in a computer. The term “memory” usually refers to the main memory of the computer, whereas, the word “storage” is used for the memory that exists on disks, CDs, floppies or tapes. The main memory is usually called a physical memory which refers to the ‘chip’ (Integrated Circuit) capable of holding data and instruction. There are different types of memory. They are Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM). Random Access Memory RAM Read Only Memory ROM  Memory Unit Types of Read-only Memory (ROM) include: ROM chips PROM chips EPROM chips EEPROM chips  Memory Unit DON’T FORGET: Cache Memory Virtual Memory CMOS (complementary metal oxide silicon  Input Devices Keyboard (Text – Numbers – Commands)  Input Devices Mouse (Click – Double Click – Right Click Commands)  Input Devices Scanner (Images – Photos – Printed Documents – Codes - …) Input Devices  Input Devices Digital Camera (Photo – Video)  Input Devices Light Pen (Text – Numbers – Drawings)  Input Devices Magnetic Reader (Credit cards, ATM cards (banks), petro cards, etc. stores data in a magnetic strip which can be read easily by the magnetic reader.)  Input Devices Microphone (Audio – Speech) Input Devices  Output Devices Monitor (a visual display of data)  Output Devices Printer (a hardcopy printing of data) Output Devices Output Devices Speakers Output Devices Plotter  Storage Logical File Representation Physical file representation Data are stored as files and are Computers access a organized in different folders with particular document stored on a particular structure. a storage medium using its File: Anything stored on a storage physical location or locations medium, such as a program, document, digital image, or song Filename: Name given to a file by the user Folder: Named place on a storage medium into which files can be stored Logical File Representation  Storage Devices Data storage devices are classified as: Magnetic – like hard disk drive, tape drive and Floppy disk drive Optical – like CD and DVD Electrons (flash memory media) Hard Disk  Hard Disk Internal hard drives External hard drives Commonly used to transport large amounts Permanent storage devices of data from one computer to another located inside the system unit Portable external hard drives are smaller Removed only if a problem and easier to transport develops Most connect with a USB connection although some may be wireless  Hard Disk Hard Drive Speed, Disk Caching, and Hybrid Hard Drives: Disk access time: – Total time that it takes for a hard drive to read or write data – Consists of seek time, rotational delay, and data movement time SSDs don’t require seek time or rotational delays Disk cache: – Memory used in conjunction with a magnetic hard drive to improve system performance – Typically consist of memory chips on a circuit board inside the hard drive case Hybrid Hard Drive – Combination of flash memory and magnetic hard drive – Uses flash memory for cache – Allows encryption to be built into the drive Hard Disk  Hard Disk Hard Drive Partitioning and File Systems Partitioning: Partitions used to create: – Divides the physical capacity of a – A recovery partition single drive logically into separate – A new logical drive for data areas, called partitions – A dual boot system – Partitions function as independent hard drives – Referred to as logical drives – Increases efficiency (smaller drives use smaller clusters)  Hard Disk Hard Drive Partitioning and File Systems File system – Determines the partition size, cluster size, maximum drive size, and maximum file size FAT, FAT32, and NTFS  Hard Disk Hard Drive Interface Standards Determine how a drive connects to the computer Common standards – Parallel ATA (PATA) - older, slower standard – Serial ATA (SATA) – eSATA – SCSI and the newer serial attached SCSI (SAS) – Fibre Channel – Fibre Channel over Ethernet (FCoE) – Internet SCSI (iSCSI)  Hard Disk Hard Drive Interface Standards Magnetic Tape Disk Floppy Disk  Optical Disk – Three categories of discs: CD, DVD, or Blu-Ray Disc (BD) – Can be read-only, recordable, or rewritable – Almost always downward compatible – Can support single or dual Optical Disk Optical Disk  Flash Memory Storage Systems Flash Memory: – Chip-based storage medium that represents data using electrons – Used in SSDs and hybrid hard drives Embedded Flash Memory: – Flash memory chips embedded into products, such as: Portable digital media players, digital cameras Handheld gaming devices, GPS devices, mobile phones Sunglasses and wristwatches  Flash Memory Storage Systems Solid-state drives (SSD): Uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. This makes SSDs much faster than magnetic HDDs. SSDs have no moving parts, make no noise, are more energy efficient, and produce less heat than HDDs.  Cloud (Online) Storage It is accessed via the Internet. Via Web sites (Flickr, Facebook, Google Docs, etc.) Via online storage sites (Box, Dropbox, etc.) Growing in importance because more and more applications are Web based Increasing being used for backup purposes Files can be synched between PC and cloud storage Many Web sites providing online storage offer it free Business cloud storage is available Cloud (Online) Storage