Nat 4/5 Computing Science Lesson 8: Input, Output and Backing Storage Computer Systems Nat 4/5 Computing Science Lesson 8: Input, Output and Backing Storage

Lesson Aims By the end of this lesson: Pupils will be able to: Describe the features, functions and uses of these input devices : Keyboard, Mouse Microphone, sound card Trackpad, graphics tablet, touch-sensitive screen Joystick digital still camera, digital video camera Sanner Webcam Dataglove Interactive whiteboard

More aims By the end of this lesson: Pupils will be able to: Describe the features, functions and uses of these output devices:- Monitor inkjet printer, photo printing, 3-D printing, laser printers, plotter loudspeakers, headphones, sound card Graphics card Headset Multimedia projector Compare devices using appropriate characteristics including - resolution, capacity, speed of data transfer, cost

Nat 4/5 Input Devices An input device is hardware that lets you put information INTO the computer e.g. Keyboard, mouse Microphone, sound card Trackpad, graphics tablet, touch sensitive screen Joystick Digital Still Camera / digital video camera Scanner Webcam Data glove

Input devices

More input devices

Nat 4/5 Output Devices An output device is hardware that gives the user information from the computer system e.g. Monitor Inkjet printer, photo printing, 3-D printing, laser printers, plotter loudspeakers, headphones, sound card Graphics card Headset Multimedia projector

Output Devices - monitors

Output devices

Nat 4/5 Input/output Devices You have to be able to compare these devices in terms of appropriate characteristics such as: Resolution Speed of data transfer Cost – initial cost and running cost

Examples Type of printer Purchase price Resolution (dpi) Speed (ppm) Ink/toner Interface Colour? Y/N CANON iP7250 Wireless Photo Inkjet Printer 49.99 9600 x 2400 15 b&w 10 colour Ink USB, WiFi Y EPSON WorkForce Pro WP-4535DWF Wireless All-in-One Inkjet Printer £179.99 4800 x 1200 26 b&w 24 colour USB, Ethernet, WiFi BROTHER HL2130 Compact Monochrome Laser Printer 2400 x 600 20 Toner USB 2 N Samsung CLX-9250ND/SEE Colour Laser A3 MFP £19,123 9600 x 600 25 Ethernet, USB?

Backing Storage

a group of 8 bits – Single Letter Nat 4/5 Storage Terms Term Abbreviation Description Bit binary digit, 0 or 1 BIGGER -> Byte a group of 8 bits – Single Letter Kilobyte Kb 1024 bytes Megabyte Mb 1024 Kilobytes Gigabyte Gb 1024 Megabytes Terabyte Tb 1024 Gigabytes

Types Of Access Sequential Access Direct/Random Access Nat 4/5 Types Of Access Sequential Access Direct/Random Access To go from file A to file Z in a sequential-access system, you must pass through all files in order. Sequential access is sometimes called serial access Refers to the ability to access data at random. In a random-access system, you can jump directly to file Z. Disks are random access media, whereas tapes are sequential access media

Nat 4/5 Backing Storage Backing storage is used to save permanent copies of your files onto. There are 3 main types Magnetic These use magnetic fields to store the data Floppy Disks/Hard Disk Drives Magnetic Tapes Optical These store data by means of lasers ‘burning’ a disk CDROM/DVD/Blue Ray Solid State (N5) This uses no moving parts at all, uses memory chips USB Drives SSD Hard Drives

Magnetic Storage Most likely a Hard Disk Drive Points to look for are: Need to know it’s capacity How much it stores It’s speed – how fast the disk is turning Written as rpm – revolutions per minute High capacity and high speed are best Can be internal or external (portable)

Hard Disk Drives (HDD’s) Nat 4/5 Hard Disk Drives (HDD’s) Hard Disk Drives are usually stored inside the computer. They use disks of metal which are magnetically charged. These are read by a small head –which moves over the disks. Very large storage capacity Very fast data access speeds Type Of Access Direct/Random Capacity Up to 3TB Portability Internal model (NO) External models (YES) Price Approx £40 - £220

Magnetic Tape Magnetic tapes are essentially the same as music tapes. Nat 4/5 Magnetic Tape Magnetic tapes are essentially the same as music tapes. To access a file you have to sequentially go through every file by fast forwarding or rewinding. They are however relatively cheap and easy to store. Often used for backups Type Of Access Sequential Capacity Up to 200GB Portability Very portable, requires a tape drive Transfer Rate Up to 20Mbps Price Up to £20 per tape

Optical Storage CD (Compact Disc) DVD(Digital versatile Disc) N4/N5 Optical Storage CD (Compact Disc) DVD(Digital versatile Disc) BD (Blu-ray Disc) Need to know it’s capacity Some disks have more than one layer – holographic discs! It’s form ROM = Read Only – cannot be changed R = Writable – can write data on the disc RW = Rewriteable – can write data on the disc and change or delete it later

Optical Storage – CD/DVD Nat 4/5 Optical Storage – CD/DVD CD, DVD, and BD’s are optical media A spiral track is used to store the data A laser is used to burn holes (pits) into the surface of the disk on a ROM disc A lower power laser is used to read the data Type Of Access Direct/Random Capacity CD: 700MB (80 minutes audio) DVD 4.7GB up to 50GB Blu Ray Portability Very portable, requires another drive Price CDR: 20-30p DVDR: 30p-£1

Optical Storage capacities Capacity CD-ROM CD-R CD-RW DVD-ROM DVD-R DVD-RW Blu-Ray 700Mb 4.7Gb 25-50Gb

Uses of optical discs CD-ROM - distribute data: software (e.g. office applications or games), music, electronic books e.g. an encyclopaedia with sound and video DVD-ROM - larger capacity so used to distribute video Blu-Ray discs - even larger capacity so used for HD video

Storing your data on optical disc CD-R, DVD-R = Writeable storage media –you can “burn” you files onto them CD-RW, DVD-RW = re-writeable storage media – you can write data on the disc and change it later

Solid State Devices (SSD) N5 Solid State Devices (SSD) Soli State means “no moving parts” – data stored on chips Known as ‘Flash Memory’ Many portable computers contain built-in SSD’s Portable Rewritable Data can be read much faster than either optical or magnetic devices Hybrid drives contain HDD as well as SSD Uses less power than optical and magnetic drives Large capacity

USB Flash Drives Very robust. Nat 4/5 These are often used in MP3 – Players – Ipod Nano/Shuffle uses this. Some are even waterproof or branded with company logos Type Of Access Direct/Random Capacity Up to 128GB Portability Very portable, only requires USB port Transfer Rate 10-30MBps Price £10-£100+

Summary There are three main types of backing storage Optical Magnetic Solid State There are two main types of access Sequential Direct/Random Input Devices put information INTO the computer Output Devices get information FROM the computer

Lesson 8 - Task Worksheet 8