COMP 1017 Digital Technologies Session 1

What is a computer? In small groups Four attributes of a computer –What is it? –What does it do? 5 minutes

Are these computers? Abacus Stonehenge Pocket calculator VCR Microphone Typewriter Bathroom scales Car speedometer Thermostat A person

History of Computing (Origins) 3400 BC: counting in tens (Egypt) 2600 BC: Abacus (China) BC: Stonehenge completed 260 BC: base-20 counting – including zero (Maya – Central America)

Abacus from

Stonehenge from

History of Computing (Europe and Britain become important) 967 AD: Zero in the eastern hemisphere (Muhammad Bin Ahmad) Around 1500: Design of mechanical calculator (Leonardo da Vinci) 1614: Logarithms (John Napier) 1621: Slide rule (Edmund Gunter, William Oughtred)

Slide rules from

History of Computing (Europeans – then Britain again) 1642: Adding machine (Blaise Pascal) 1679: Binary arithmetic (Gottfried Leibnitz) 1820s and 1830s: Charles Babbage’s Difference Engine and Analytical Engine

Babbage from

Britain again (hooray!) 1843: The idea of Computer Programming (Ada Lovelace (Byron)) Image from

More British Innovation 1904: Vacuum tubes (birth of electronics) (John Fleming) Image from

The Second World War 1936: Programmable computer constructed (Konrad Zuse) 1947: Transistors (John Bardeen, Walter Brattain & William Shockley) Image from

US Corporations Take Over 1960: First minicomputer, the PDP-1 (Program, Data, Processor) 1971:Floppy disks (IBM: Alan Shugart et al.) 1981: IBM PC launched 1989: World Wide Web founded at CERN (Sir Tim Berners-Lee) (Brit)

Digital (see later for more detail) use state to represent data i.e. on or off e.g. the presence of an electric voltage 0 volts = off, 5 volts = on binary

Digits from

Digital multimeter from radio.com/catalog/fm_txvrs/ ht ml

Analogue Uses physical entities to represent data e.g. the size of an electric voltage, the frequency of a signal, etc.

Analogue multimeter from multimtr.htm

Digital v. Analogue No fuzziness in digital –exact value No fractions in digital –precision of value limited to last digit Electronics easier with digital

Precision is important Computers are incredibly stupid and gullible. (Pete Moody’s First Law of Computing) A computer will do what you tell it to do, but that may be very different from what you had in mind. (Joseph Weizenbaum)

Information What is the difference between Data and Information? ?

Measures of data A bit is a binary 1 or a zero A byte is the amount of data that stores one character “A” or “+” or “  ” or (Usually 8 bits nowadays) 1 kilobyte is (roughly) 1000 characters Actually 1024 = 2 10 characters

Jargon 2 10 bits = 1024 bits = 1kbit 2 20 bits = bits = 1 Mbit (different from normal use: 1 km = 1000 m; 1000 g = 1 kg 1 MW = W) Also used for bytes: kbytes and Mbytes

More Measures of data Megabyte = one million bytes (actually = 2 20 ) Gigabyte = one billion bytes (actually 1.07 x 10 9 = 2 30 ) Terabyte = one trillion bytes (actually 1.10 x = 2 40 )

Future Measures of Data petabyte (2 50 bytes) exabyte (2 60 bytes) zettabyte (2 70 bytes) yottabyte (2 80 bytes) …

Hardware The parts of a computer that can be picked up or touched or thrown out of the window

Input Hardware (see later) Keyboard Mouse etc… Different designs of each

Keyboard from

Computer mouse from

Output Hardware (see later) Monitor/VDU Printer etc… Different designs of each

Computer monitor from

Computer Printer from

Primary Storage (see later) Electronic chips in the main computer case Close to and permanently connected (hard-wired) to the main processor RAM (random access memory) ROM (read only memory)

Computer Memory Board from

Secondary storage (see later) Hard disk Floppy disk CD-ROM (disc) –Some rewritable, so not really ROMs Memory stick/card etc.

Floppy disk from

Hard disk from

Coffee mug holder from

Memory card from

Memory Stick from

Processing (see later) Motherboard Microprocessing chip Bus (connections within the main box)

Motherboard from

Software (see later) The components of a computer that are not physical

Operating Systems Basic general ‘housekeeping’ routines DOS, Windows, Mac OS, Unix, Linux, etc.

Application software MS-Word (& other word processors) MS-Access (see COMP1008) (& other databases) MS-Excel (see BUSM1115) (& other spreadsheets)

Applications (continued) MS-Powerpoint (& other presentation packages) Visual Basic (see COMP 1026) (& other programming languages) Other program(me)s image processing, games, networking software…

Communications (see later) Modem Enables sending & receiving via a telephone line or a radio connection Connection to www

Communications The Digital Information Superhighway www (internet) Problems: Accuracy of information Junk (spam) Referencing

The Three (+1) rules of computing 1. Computer components get smaller. 2. Computers get more powerful. 3. Computers get less expensive. 4. Computers are always changing, so a lecturer in Information Technology is always out of date.

Miniaturization from

The Five Types of Computer Embedded PC Mainframe Super Miniature

Embedded computers Hard-wired into an appliance Calculator, car, washing machine, microwave… Single application

The car computer from a Ford Ranger from

PC PC: Desktop/Tower, Laptop, PDA (Personal Digital Assistant) Workstation: Desktop, powerful versions of PCs. Used for computer-aided design, software development, scientific modelling, etc. (see BUSM 1115)

Workstation from

Another workstation (for those really addicted to their computer) from

Mainframe Large Need air-conditioned room or building Uses: Banks, Air Traffic Control, Scientific Research, etc.

Mainframe from

Supercomputers Fill a building Used for: –Weather Prediction –“Star Wars” defense systems –Finding prime numbers –Searching for signs of Extra Terrestrial Intelligence (SETI)

Supercomputer from

Mobile phones Input Output SoundRadio waves Keypad presses Radio waves Screen display, radio waves Sound, screen display

Mobile phone mountain from

iPods Stores and plays music files –Can also store other files Inputs: music files, input clicks Outputs: screen display, sound

iPod from

Xboxes and similar Inputs: game files, game controller signals Outputs: screen, sound, (touch?)

Xbox from

PDAs Functionality: –Clock –Diary –Address book –Task list –Memo pad –Calculator Can by synchronised with PC

PDAs (2) Other functions –Touch-sensitive screen –Note-taking Small keyboard or stylus input with handwriting recognition –Web browser –Media player

PDA from

Speed of Computers Gigahertz clock speed (PCs) MIPS (Millions of Instructions Per Second) (mainframes) TERAFLOPS (thousand billion Floating Point Operations Per Second) (supercomputers)

Computers don’t need tea-breaks From