Different uses of the computer

1. Different uses of the computer UC Santa Cruz CMPS 10 – Introduction to Computer Science www.soe.ucsc.edu/classes/cmps010/Spring11 ejw@cs.ucsc.edu 1 April 2011

2. Class website • http://www.soe.ucsc.edu/classes/cmps010/Spring11/ • Please write this down, and bookmark it • Holds: • Syllabus (including homework due dates) • Homework assignment descriptions • Description of course readings • Links to class lecture notes • The final exam is scheduled for Tuesday, June 7, 8am-11am • This class will have a final exam. Please plan on this.

3. The many uses of computers • Today, computers are used in many ways • Computation • Large scale scientific simulations, spreadsheets • Data processing • Classic business functions: accounting, inventory control, order processing, customer management, payroll • Device control • Embedded computers in a range of devices controlling their functions • Command and control • Battlefield awareness, air traffic control • Tool for individual expression • Word processors, image editors, music and movie editing • Computational media • Web, computer games • Communications • Cell phones, email, instant messaging, internet telephony (Skype) • Sensors • Measuring various aspects of the world World’s smallest computer? A prototype of an implantable eye pressure monitor for glaucoma patients. Contains an extremely low-power microprocessor, a pressure sensor, memory, a thin-film battery, a solar cell and a wireless radio with an antenna that can transmit data to an external reader. Developed at Univ. of Michigan. www.foxnews.com/scitech/2011/02/23/worlds-smallest-computer-created/

4. Interpretive flexibility of the computer • An unusual quality of the computer is its wide range of uses • Most technologies are single-purpose • A knife is used for cutting. A jacket keeps you warm. • Some have 2-3 purposes • A flat-head screwdriver is useful for turning screws and opening paint cans • Very rarely they have multiple purposes • Consider the wide range of lights used for many different lighting needs, from household lights to stage and cinema lighting • But, still these tend to be variants on the core function of the technology • Most uses of lights are for illumination • The computer is different • A broad range of uses, where many uses are substantially different from one another • It is unusual to have a single technology with such a broad range of uses • Basic building materials (wood, steel, concrete) also have a wide range of uses, but are the building blocks of other technologies

5. Why is the computer so flexible? • Some thoughts • The computer can represent a wide range of activities • A wide range of things in the real world can be modeled as numbers and letters, which can be stored and processed inside a computer • Analog to digital (and digital to analog) converters allow a computer to interact directly with the real (analog) world • Allows the world to be represented as pure information, which can then be manipulated inside a computer • Permits a computer to send/receive messages • Permits a computer to measure the real world • Permits a computer to control devices in the world • Programs can encode very complex logic, which enables a computer to behave in multiple, complex ways

6. Computation and Simulation • The computer is used to perform large numbers of computations quickly • Key driver of supercomputing • Areas of large-scale simulation: • Combustion (and complex fluid simulation) • Astrophysics • Modeling formation of stars, black holes, evolution of galaxies • Life sciences • Modeling behavior of biochemistry • Protein folding • Gene sequencing • Environment • Modeling world climate • Also: personal calculators • An increasingly niche area of computing Visualization of combustion temperature inside a gas turbinewww.psc.edu/research/fetc/combustor/combustor.php Climate modelwww.drroyspencer.com/2009/07/how-do-climate-models-work/

7. Simulation and the Sciences • In most sciences, the computer has emerged as a kind of research instrument • The computer permits the construction of executable models • Scientists develop theories • These theories are converted into models • The models are turned into software and executed • The output of the models can be compared with real world behavior • OR, models can suggest new avenues of experimentation • Very complex computer models include the experimental and theoretical results of multiple scientists • The programs act to synthesize together multiple results in a coherent way

8. Data processing • The foundation of large-scale modern business • Scaling large organizations requires them to develop rules, processes, and policies. • These must be enacted in a consistent way, at large scale • The computer is a powerful tool for ensuring consistency of enactment of rules and processes • It permits a small number of staff to manage a large flow of data • But, also reduces the cost of making more complex policies and procedures • Hence, introduction of computers tends to make bureaucratic systems more complex. • It also makes it easier for groups to exercise control, and hence supports power centralization tendencies • Examples: • Document management (claim processing, records management), accounting, payroll, inventory control, point-of-sale, tax form processing, order processing, workflow management, many others

9. Device control • Use of the computer to control the behavior of a device • Key advantages over use of static controllers: • Software permits a device to be given new behavior without changing its hardware • Software permits a device to behave in complex ways • Software typically permits a device to support more functions than the same device without software • Wide range of uses • Embedded controllers in many devices • Examples around the home: television, radio, microwave, cable box, advanced thermostats, recent cars, telephones, telephone answering machine, advanced refrigerators and ovens, digital camera, digital movie camera, digital music player, wifi router, advanced dishwasher, advanced washing machine ArduinoArduino board, a microcontroller designed for hobbyist use (US $30) www.arduino.cc

10. Command and control • The computer is used to provide a visualization of a complex arena of (human) activity • Battlefield, aircraft landing, chemical plant, railroad control • Permits small staff to: • Understand the state of a complex system • Take action or direct actions of others within that system Potomac TRACONen.wikipedia.org/wiki/Air_traffic_control Union Pacific Harriman Dispatch Centeren.wikipedia.org/wiki/Union_Pacific_Harriman_Dispatch_Center

11. Tool for individual expression • As computers dropped in price, in the 1970s it became possible to have computers owned by individuals instead of companies and governments • Emergence of personal computing (microcomputers) • Led to widespread adoption of tools for expressing individual thought • Word processor & spreadsheet, then later desktop publishing, music editors, movie editors, slide presentations and many others • Emergence of computer programming as a middle class hobby Cover of Computer Lib, by Theodor Holm Nelson, 1974 The first book to really explore what it would mean to have a personal computer.en.wikipedia.org/wiki/Computer_Lib

12. Computational Media • Computers have given rise to more new forms of media than any other technology • Closest competition is the printing press • Computer games, world-wide web, interactive CD-ROM, email, instant messaging, multi-person virtual worlds, digitally animated movies, Twitter, Facebook, etc. • A major new form of computational media has been emerging every 3-7 years • This is an astonishing rate of new media creation • A computational media is one is which computation is a core requirement for the delivered experience. • Computer games: yes, need computation to enact a game • MP3 music: mostly just a digitization of an existing media, analog recorded music. Think of these as digital media, but not strongly computational. Scene from Minecraftwww.geeksmack.net/apple/minecrafts-brief-appearance-in-the-app-store

13. Communications • Computers forming the heart of a system of communication among people • Cell phones, email, instant messaging, Facebook, internet telephony (Skype) • Also, now the underlying technology for television and partially radio • Key enabling technology: Internet • Computers began as a technology for computation • Today, embedded control and communications are the primary uses of computers • For the average person, communication is their primary use of computing • In the future, the first computer a person will buy is a cell phone Erna Schneider HooverInventor of computer controlled telephone switching, developed the archtiecture of the Bell System ESS phone switching system. BA Medieval History (Wellesley), PhD Philosophy and Foundations of Mathematics, Yale

14. Sensors • A new area of computing is the creation of networks of computers to perform sensing activities • Known as sensor networks • Builds on low-cost of embedded microcontrollers and increasingly low cost of wireless networking • Permits low-cost measurement of wide areas of the world A diagram of a sensor network proposed for the Andrews Forest.oregonstate.edu/feel/about

15. Homework assignment #1 • First part • Pick a computer in your home, one that isn’t a general purpose laptop or desktop computer. • Briefly name the device, and what you use it for (1-3 sentences) • Broadly, describe what function(s) the computer inside this device performs • Example: dishwasher: receives instructions on which wash cycle to perform, and controls the dishwasher’s wash cycle • Do your best on this: think about what needs to be controlled, what kinds of inputs and outputs are provided (Is there a keypad? A display?) • If a device has a primary function and a computer, the computer is probably in control of that primary function • Using the categories from this lecture, describe the use (or uses) it falls under, and some explanation why. • Consider what would happen if that computer either disappeared, or was replaced by an earlier version of a device without the computer. How would your life be different? That is, what has been the impact of the computer on this device?

16. Homework assignment #1 • Part two • Consider a computing system you don’t own • Name and briefly describe this computing system • Describe how you are dependent on this computer. That is, what would happen if this computer stopped working for a month?