Ch. 1: Computation's Greatest Hits

Developments.
1. Digital information: Just information represented by numbers.
  1. People have used digital information pretty much forever; using machines to manipulate them is new.
  2. First production use of machines for numbers.
    1. Herman Hollerith
    2. 1890 census.
    3. Card reader not considered a computer: No program.
2. Stored-Program Computers.
  1. Data equipment is much more useful when it can be programmed to perform different functions.
    Photo: Chris Shrigley. CCL
  2. Earliest versions used plugs. (Pictured is for an IBM 402 Card Tabulator.)
  3. Stored-program computers keep the program in memory.
  4. Changing programs is much faster.
  5. Still large and expensive machines.
3. Transistors.
  1. Early computers used vacuum tubes.
    1. Heated, using lots of power.
    2. Routinely burn out.
    3. Large (light-bulb size).
  2. Transistor invented in 1947.
    1. Can operate at room temperature.
    2. Long life span.
    3. Smaller.
      First commercial ones are the size of a pencil eraser.
4. Integrated circuits.
  1. Discrete transistors must be connected to build larger circuits.
  2. This takes time, and connections can break.
  3. ICs are constructed from many connected transistors at once.
  4. The transistors and their connections are all created in a single operation.
  5. Process, photolithography, is similar to printing.
  6. First ICs contained tens of transistors.
  7. Current microprocessors contain millions.
5. Personal computers.
  1. Early computers were big, expensive shared corporate resources.
  2. Advance of IC technology made then shrink from a room to a desktop, then to a pocket.
  3. And lowered the price.
6. The Internet.
  1. Early networks connected computers of the same type.
  2. ARPANET, first run in 1969, connected computers of different types.
  3. Originally used for text connections and file transfer.
7. The World-Wide Web.
  1. Tim Berners-Lee.
  2. A way to make the web more usable.
  3. Originally designed to speed up the sharing of physics research.
8. Layered Software.
  1. Software is organized in layers.
  2. Each layer provides services to the layer above.
  3. Layers
    1. Applications.
      1. Word processors, web browsers, games.
      2. On phones, conventional to say “apps”.
    2. Libraries and utilities.
      1. Programmer's reusable parts.
      2. Display an open-file dialog, request a web page from a server, search for a specified user in the accounts database.
    3. Kernel.
      1. Interface between hardware and software.
      2. Create a file, report mouse movements or screen touches, place a block of data onto the network.
    4. Hardware
Hardware
1. A processor, which follows the program and runs the machine.
  1. Most PCs use some form of the Pentium from Intel.
  2. Many phones use an ARM processor, made by various manufacturers.
2. A memory which holds program and data.
3. Various connected peripheral devices.
Software
1. The collective terms for program.
2. An algorithm is a precise, systematic method for producing a specified result.
  Think long division
3. A program is an algorithm expressed in a language the processor understands.
You need to know the right words.
1. Talking to tech support.
2. Anchoring knowledge -- experts invent words for a reason.
Words for Ideas
1. Abstract: Extract the fundamental idea.
  1. The moral to the story: Does the Prodigal Son need a name?
  2. If something is a “hardware store” what do you know about it?
2. Generalize: Find similarities to summarize multiple things.
  1. Bolts, faucets, jar lids, volume controls: Same directions.
  2. Spelling rules: I before E...
  3. Allows us to apply experience from one area in another.
3. Operationally Attuned: If you know how something works, you can figure out how to use it.
4. Mnemonic: A rule to remind you.
  1. Empty Garbage Before Dad Flips. (Notes)
  2. Gentiles Eat Pork Chops. (Galatians, Ephesians, Philippians, Colossians)
  3. Righty Tighty, Lefty Loosy.

Video: kids react to old computers.