COMP 1321 Digital Infrastructure Richard Henson University of Worcester September 2017

What is this module about? On successful completion of the module, you should be able to: LO1: Describe a range of digital platforms and networks and explain the context for use of each platform LO2: Apply tools involving digital hardware and digital logic to solve real world problems LO3: Explore the contents of a digital storage medium using computer forensic software and extract information that could be used as evidence

More Learning Outcomes LO4: Apply networking principles to provide connectivity between digital devices on a range of platforms that can be used for sharing data and control of processes LO5: Use penetration testing software, in accordance with relevant standards and legislation, to identify vulnerabilities

What is a computer? In small groups… Four attributes of a computer… What is it? What does it do? 10 minutes

Are these computers? Abacus Typewriter Bathroom scales Car speedometer Thermostat Stonehenge Pocket calculator Person DVD player Microphone

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)

Abacus

Stonehenge

Calculating machines - Precursors to Computers (Europe) 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)

Types of slide rule

(European calculating machines – continued) 1642: Adding machine (Blaise Pascal) 1679: Binary arithmetic (Gottfried Leibnitz) 1820s and 1830s: Charles Babbage’s Difference Engine and Analytical Engine

Babbage… And his analytical engine as reproduced in Sweden: http://w1.131.telia.com/~u13101111/merschwib.html

Boole: inventor of “digital” Would be 202 years old this year… https://www.youtube.com/watch?v=w_5G6yLTR6U Work buried from his death (1864) until the 1930s…

Boolean Algrebra 1840s George Boole… Whole new system of Algebra used true/false instead of numbers trying to produce a type of maths that related to philosophy Inspiration for all of us!

Programming Started with Ada Lovelace (who?) Daughter of Lord Byron Brought up on Maths (!) Developed a friendship with Babbage Wrote instructions for his machines…

European Domination of Hardware (mostly British) 1835: Electric Relay (Davy) 1904: Vacuum tubes (“valves”) birth of electronics (John – not Alexander - Fleming) The Second World War 1936: Programmable computer (Konrad Zuse, Germany) 1943: Colossus, based on relays – won the war?

Colossus – what’s that! Top secret code breaker … 9000 people worked at Bletchley Park during ww2… above, two of them… http://www.bbc.co.uk/programmes/p031vdwf http://www.youtube.com/watch?v=46SI79feHT4

Bletchley Park (shhh… Top secret!) Set up in 1940 to crack German codes… succeeded… estimated that war shortened by 2 years but no-one could talk about it! In 1985 one of the great codebreakers wrote a book… but authorities disapproved, made his life difficult, and he died young. Name: Gordon Weichman: http://www.bbc.co.uk/programmes/p031vg47

Like to go to Bletchley Park? https://bletchleypark.org.uk/ Includes a museum of Computing Could be arranged as an all day visit…???

Digital Electronics “Digital” requires two states (eg on/off) Electrical Relays achieved that… hence Colossus Electronic Valves achieved that… hence ENIAC Both very large and cumbersome

US domination (and why…) Late 1930s: Shannon dug up Boole’s work found a good fit between “true/false”, electronic “on/off” valves, and binary numbers “0/1” used Boolean Logic to create circuits wit predictable outcomes 1940s Europe devastated by war… 1947: Transistor (John Bardeen, Walter Brattain & William Shockley) like a valve but low voltage, low energy 1949: ENIAC First commercial computer 1960s: First minicomputer, the DEC PDP-1 (Program, Data, Processor)

UK computing in the 50s & 60s The first “electronic brain” http://www.bbc.co.uk/programmes/b069r3rt The first electronic office: http://www.bbc.co.uk/programmes/b069rvb4 The first electronic lottery:

Programming “A computer will do what you tell it to do, but that may be very different from what you had in mind.” Joseph Weizenbaum

US domination of software & hardware development… 1967: Relational database 1969: Internet begins with 4 mainframes 1971:Floppy disks (IBM: Alan Shugart et al.) 1972: Intel, microprocessor 1975: Apple, first microcomputer 1976: Wang, first VDU

The First “Infrastructure” Mainframes had no infrastructure Separate area of their own… Paper in… paper out! VDU allowed interaction with mainframe multiuser systems needed communication protocols and cabling

More US Dmination… 1976: Microsoft, computer language on a chip 1981: IBM PC teamed up with Microsoft first Desktop Operating system, MS-DOS used in Business Standalone, so no infrastructure…

Growth of Infrastructure… Suddenly, a requirement for computers to communicate with other computers… Hardware & protocols further refined networks grew rapidly Mainframe-mainframe PC-PC even mainframe to PC!

Development of Infrastructure Gradually replaced having one monster computer in one place… Input-output extended through dumb terminals (Wang, 1970s) Standalone desktop computers (1979) Linked together (1980s) peer-peer networks evolve into client-server client-end usable by non-specialists

Networking: Integration of Telephone & Digital Infrastructures OSI model (1978) International Standard in 1984 Telecoms…French domination stubbornly analogue… digital data had to be converted before transmission very slow evolution… Gradual evolution to digital telecoms (1990s/2000s) ADSL and fast broadband (not rural areas…)

European Comeback? From 1988: Mobile phone ARM CPU chip (Acorn) low power… used in many devices 1991: World Wide Web founded at EU research facility, CERN, under the Swiss Alps (Sir Tim Berners-Lee) Late 1990s: Linux & Nokia

More US domination i-player, i-phone, i-pad Smart phone Mobile apps Tablets & e-books Cloud computing What next?… IoT, wetware?

Analogue gives way to Digital… Computer Data… electronic (two states e.g. high/low voltage) Became known as digital Telephone system analogue (for historical reasons) high/low voltages superimposed on a sound wave transmission slow easily intercepted…

Digits? Hence… DIGITAL!!! Odd word… used to mean fingers and toes http://www.dribbleglass.com/Toes/uglytoes-2.htm therefore about whole numbers of things Gave birth to this hugely influential adjective… Hence… DIGITAL!!!

Digital but not whole? Any quantity can become digital! (not just about whole numbers) based on approximation… Electrical on/off “state” represents data as (1s/0s) presence/absence of an electric voltage low voltage or higher voltage 0-2 volts = off, 3-5 volts = on binary (off = 0, on = 1)

Digital multimeter Ref: http://www.universal-radio.com/catalog/fm_txvrs/03850208.html

What is Analogue? The “real” world Everything before Boole’s digital logic started to be used by computers… and programs could be written to depict the world Uses physical entities to represent data exactly e.g. the size of an electric voltage, the frequency of a signal, etc.

Analogue multimeter Ref: http://www.kpsec.freeuk.com/multimtr.htm

Analogue and Digital The real world has always been analogue. Since long before humans walked the earth! most inventions started out as analogue Digital World ~ post-war human invention based on George Boole’s maths… 100 years earlier Discussion: analogue or digital… which is best? Why?

Analogue to Digital Computers don’t do analogue! Devices had to be invented to convent analogue data to digital input devices always an approximation (can be a very close approximation though…)

Summary of Developments Digital only possible thanks to George Boole (1850s, UK) Hardware began with Lord Babbage, but mechanical (1850s UK) Programming started with Lord Byron’s daughter, Ada Lovelace (1850s UK) Programmable analogue machines… Electronics used Boole’s maths (1930s US) Computers programmed digitally… (late 1940s on, US - almost complete domination)