Chapter 1: What is a Computer?

Chapter 1: What is a Computer?

1. What does a computer do?

   • 1. Computers are programmable machines
   • 2. Four steps to the information processing cycle (IPC)
     • 1) Input
     • 2) Processing
     • 3) Storage
     • 4) Output
   • 3. The IPC converts raw data into useful information
   • 4. Artificual intelligence is concerned with making computers behave like humans

2. A brief history of computers

   • 1. First-generation computers used vacuum tubes
   • 2. Second-generation computers used transistors
   • 3. Third-generation computers used integrated circuits (chips)
   • 4. Fourth-generation computers use microprocessors
   • 5. Moore's Law states that the number of transistors that can be placed on an integrated circuit doubles roughly every 2 years - today it is closer to every 18 months

3. Bits and bytes

   • 1. Computers use binary (base 2) number system
   • 2. ASCII and Unicode are binary code character sets
   • 3. A bit is the smallest unit of digital information
   • 4. A byte is equal to 8 bits and represents 1 character

4. Let's get personal

   • 1. Desktop computers give you the most bang for your buck
   • 2. Notebook or laptop computers are portable PCs
   • 3. Subnotebooks and netbooks are specialized notebook computers
   • 4. Tablets fall somewhere between notebooks and smartphones
   • 5. The primary difference between a Mac and a PC is the software

5. Beyond the desktop

   • 1. Smartphones and tablets are handheld mobile devices
   • 2. GPS is a satellite-based navigation system
   • 3. Wearables are computers worn on the body
   • 4. Today's video game consoles are eighth-generation systems with high-end graphics and processing

6. Multiuser computers

   • 1. Servers provide services such as file and print sharing and email to client computers
   • 2. Minicomputers have largely been replaced by midsized servers that can support hundreds of concurrent users
   • 3. Mainframes and enterprise servers can process millions of transactions in a day
   • 4. Supercomputers perform complex mathematical calculations for such things as weather forecasting and medical research
   • 5. Distributed, grid, and volunteer computing distribute processing tasks across multiple computers

7. Ubiquitous computing

   • 1. Ubiquitous computing is technology that's invisible to us
   • 2. Embedded computers are found in everything from traffic lights to dishwashers
   • 3. The convergence of technology allows us to carry a single multifunction device that can do the job of many separate devices