Unit A Pages A-1 through A-25 of the Concepts Book

Defining Computers A computer is a device that accepts input, processes data, stores data, and produces output A computer system includes hardware and software Hardware includes the physical electronic and mechanical parts of the machine Peripherals expand the computer’s capabilities Software is the term used to describe the instructions used to run the computer (yes, there are exceptions)

Computer Functions Four main computer functions: IPSO Input – verb or noun Noun = whatever is “fed” into the computer Verb = to put something into the computer Process – manipulations done to the input Data vs. Information Computer process data in the CPU Store or Storage Data and instructions are kept in memory Output – verb or noun Noun = whatever is produced by the computer Verb = to produce a result

Categorizing Computers Microcomputers or personal computers (PCs) Most home computers, usually one user at a time Minicomputers Small businesses, several users Terminal used for input/output, but not processing Mainframes Larger, faster, more users, more processors Supercomputers Largest, fastest, most expensive A computer network is a collection of computers and other devices which are connected and communicate with each other to share data, hardware, and software

Examining Microcomputers A platform is a major type of microcomputer design (usually refers to the operating system involved) For this class, the two platforms are IBM- compatible and Macintosh IBM-compatible machines are also called Windows machines or Windows platform Compatible computers or peripherals will work together and operate in essentially the same manner Hardware Product Life Cycle Alternative Forms: PDAs, notebooks, laptops

Peripheral Devices A peripheral is a piece of equipment used with, but not part of, a computer (this definition has changed over time) Peripherals add capabilities Peripherals usually require special software/device drivers (explained later) Examples of peripherals include monitors, printers, scanners, joysticks, cameras, graphics tablets, and mice

Examining Keyboards A keyboard is usually the primary input device Cursor _ vs. Insertion Point (I-bar) Important parts of the keyboard Numeric Keypad Function Keys Modifier Keys A keyboard shortcut is a combination of two or more keys that produce an action when pressed sequentially or together What are some examples of toggle keys?

Examining Monitors Character-based (monochrome) display Fixed-proportion, unmodifiable, mainframe days Adapted character-based display (emulator in a windowing system) Graphics-based (color/bitmap) display Screen size (advertised vs. vis) Pixels and dot pitch (distance in millimeters) Two-dimensional resolution, number of colors What the heck are CRT, RGB and LCD?!?

Examining Printers Three main types Dot matrix Ink jet Laser What are dpi, ppm and cps? What is PostScript? What is a PostScript error? Okay, why CMYK?

Prompts & Command Lines Prompt: text message which asks for a simple response from the user Command Line: user enters special or reserved words Pros – very simple, very structured (standard) Cons – parameters, syntax errors, inflexible and unhelpful Computer games by Infocom Leather Goddesses of Phobos

Wizards, Menus, and Dialogs Wizard: sequence of (usually graphical) screens for completing multi-step tasks Menu: list of options/items, possibly in a submenu hierarchy Dialog Box: area for graphical display and entry of options associated with a command Pros – flexible, forgiving, may have contextual help, graphical Cons – may take longer to complete a task than a command line, may present too many options

Elements in Menus and Dialog Boxes Menu headings and items Submenus Grayed-out items Ellipsis and arrow (continuations) Spin boxes Drop-down/pop-up lists Radio buttons and check boxes Buttons

GUIs Graphical objects represent real world Windows and icons Usually manipulated by pointing device Mouse terms Click Double-click Right-click Drag

Using Resources/Help Three Little Pigs vs. Charlotte’s Web Reference manuals Technical support Telephone Online knowledge base Online chat Tutorials and on-line application help

Can Computers Think? Cogito ergo sum? Turing Test Chinese-Room Thought Experiment ELIZA