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
Abacus Stonehenge Pocket calculator VCR Microphone Typewriter Bathroom scales Car speedometer Thermostat A person Are these computers?
History of Computing (Origins) • 3400 BC: counting in tens (Egypt) • 2600 BC: Abacus (China) • 1900-1600 BC: Stonehenge completed • 260 BC: base-20 counting – including zero (Maya – Central America)
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 rulesfrom http://osaki.cool.ne.jp/other/other/sliderule/sliderule.html
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 http://w1.131.telia.com/~u13101111/merschwib.html
Britain again (hooray!) • 1843: The idea of Computer Programming (Ada Lovelace (Byron)) Image from http://www.adahome.com/Ammo/Gallery.html
More British Innovation • 1904: Vacuum tubes (birth of electronics) (John Fleming) Image from http://www.wa3key.com/tubes.html
The Second World War • 1936: Programmable computer constructed (Konrad Zuse) • 1947: Transistors (John Bardeen, Walter Brattain & William Shockley) Image from http://www.interq.or.jp/japan/se-inoue/e_transist.htm
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
Digital multimeterfrom http://www.universal-radio.com/catalog/fm_txvrs/03850208.html
Analogue • Uses physical entities to represent data • e.g. the size of an electric voltage, the frequency of a signal, etc.
Analogue multimeterfrom http://www.kpsec.freeuk.com/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 = 210 characters
Jargon • 210 bits = 1024 bits = 1kbit • 220 bits = 1048576 bits = 1 Mbit • (different from normal use: 1 km = 1000 m; 1000 g = 1 kg 1 MW = 1 000 000 W) • Also used for bytes: kbytes and Mbytes
More Measures of data • Megabyte = one million bytes (actually 1 048 576 = 220) • Gigabyte = one billion bytes (actually 1.07 x 109 = 230) • Terabyte = one trillion bytes (actually 1.10 x 1012 = 240)
Future Measures of Data • petabyte (250 bytes) • exabyte (260 bytes) • zettabyte (270 bytes) • yottabyte(280 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
Output Hardware(see later) • Monitor/VDU • Printer etc… • Different designs of each
Computer monitorfrom http://www.cheap-computers-guide.com/cheap-computer-parts.html
Computer Printerfrom http://www.zylar.com/electronic-apps.html
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 Boardfrom http://www.swtpc.com/mholley/Tanner64K/64K_RAM_Index.htm
Secondary storage(see later) • Hard disk • Floppy disk • CD-ROM (disc) • Some rewritable, so not really ROMs • Memory stick/card • etc.
Floppy diskfrom http://www.nhsia.nhs.uk/def/pages/inform/informish7/informp6.asp
Coffee mug holderfrom http://www.monitortech.com/CDDrive.html
Memory cardfrom http://wwwde.kodak.com/global/en/service/digCam/dc290/ownerManual/ch18.shtml
Processing(see later) • Motherboard • Microprocessing chip • Bus (connections within the main box)
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 e-mail www (internet) • Problems: Accuracy of information Junk e-mail (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.