Comp1004 Winter 2016 Carleton University By Andrew Runka With notes from Dr. Irwin Reichstein Memory Aids Finger Counting Counting stones, Tally sticks, Counting rods, etc Abaci Fixed Program Devices Antikythera Mechanism (c. 205-100 BCE) Various clockwork mechanisms Slide rules (c. 1600s) to modern calculators Difference Engine (c. 1800s) General purpose computers Analytical Engine (c. 1837) ▪ Punch cards, read/write, assembly language ▪ Integrated memory Turing Machine (c. 1931) ▪ “Turing-Complete” Modern Computers ▪ Store, retrieve, and process data ▪ Programmable Von Neumann Architecture CPU: Processes data and programs Memory: Stores data and programs in circuits Input/Output: Data to/from user or auxiliary storage Fetch-Decode-Execute Cycle Control Unit gets the next instruction from memory Determine what actions it requires Do those actions Supercomputer Used for massive calculations (e.g. Weather forecasting) Mainframe computer Deal with large volumes of input/output (e.g. Google) Minicomputer (between mainframe and personal) Multi-user, declined in use in mid-90’s due to cheap microprocessors Microcomputer (personal computers) Ubiquitous nowadays From desktops to mobile devices Servers Dedicated to a single service E.g., Web servers, File servers Personal Computers Standard desktop/laptop Mobile Devices Smart phones, Tablets, Smart cards Embedded Computers E.g., In a car or washing machine Types of parts Input devices Output devices Auxiliary Storage Main System Keyboard Primary input device Input of alphanumeric characters Mouse Pointing and clicking (Graphical interaction) Used in conjunction with display screen Selection, positioning (cursor), drawing, moving Microphones Convert sound waves to data Sampling rate measured in Hz (samples per second) Scanners Convert light into data Like coloured photocopiers Picture quality measured in Pixels Per Inch (PPI) Controllers/Joysticks Specialized inputs for game interactions Many more... Cameras/Webcams Stylus/light pen Fingerprint/Bar code readers Motion capture Magnetic Resonance Imaging (MRI) Positron Emission Tomography (PET) Display monitors Cathode Ray Tube (CRT) Liquid Crystal Display (LCD) Organic Light Emitting Diode (OLED) Augmented Reality Virtual Reality Display monitors Pixels ▪ Short for “picture elements” ▪ Smallest electronic display elements ▪ Grid of pixels composes a digital image Resolution is the number of pixels (rows x cols) Dot pitch is the distance between pixels Size is diagonal length of the monitor Refresh rate is the display frames per second (Hz) Speakers Convert data to sound Vary in sound quality ▪ Wattage, Frequency Response, Signal-to-noise ratio, etc Printers Dot-Matrix printers Ink/Bubble Jet printers Laser printers ‘Permanent’ storage of information Read/write data from/to storage Many forms over time ▪ Floppy Disk (8”, 5.25”, 3.5”) ▪ Hard Disk ▪ CDs, DVDs ▪ Flash memory Central Processing Unit (CPU) Brain of the computer Different brands (Intel, AMD, others) Different speeds (166MHz – 4.7GHz) Multi-core processors Multiple independent CPUs ‘Hyper-threading’ Main Memory Short term, working memory of the computer Random Access Memory (RAM) Volatile (erased when power goes out) Much faster than auxiliary storage Various sizes and speeds Motherboard Holds everything together Busses connecting the components Vary in terms of support for parts Power Supply Must supply enough wattage for all the parts Case Various form factors a) b) c) d) USB 2.0 PS/2 VGA DVI e) f) g) h) HDMI LAN (Ethernet) USB 3.0 Audio jacks Hardware The physical components of the machine Processor, motherboard, memory, drives, etc.. Software A program (set of instructions) Downloaded, installed, executed Firmware A program built into a microchip Bios (configuration), system settings, boot up System software Operating system (DOS, Windows, OSx, Linux) Hardware drivers Applications Utility applications (virus scans, etc) Personal (email, games, web browser) Business (word processors, spreadsheets, databases, communication) The list goes on.... Copyright Piracy ▪ Illegal copying of software and media Sampling & Sharing Open source software Copyleft Bugs 1945 Harvard: A moth found inside a huge computer Imperfect software, can cause crashes or worse! Patches are updates that fix known bugs Many bugs are unknown ▪ Testing (alpha/beta) & debugging E.g. Y2K bug ▪ (did not cause milk cartons to leak) Viruses Malicious programs ▪ Can erase data, upload bad data, replicate ▪ Must be run on your system to infect ▪ Trojan viruses can open the door to others Anti-virus scans files for known patterns Security Theft of data can be very costly/dangerous Keyloggers (a type of virus) Hackers ▪ Crack passwords ▪ Dumpster diving for info ▪ Social Engineering Encryption is a major field of Computer Science Privacy Individuals expect communications to be private Tracking cookies, user profiles Security vs. Privacy ▪ NSA surveillance ▪ Canadian Bill C-51 Ergonomics Comfortable Human-Computer interaction Chronic repetitive stress injuries Proper design of keyboards, mice, chairs, desks, etc.