What is a Computer? How Does it Work?

 All a computer can do is ◦ Accept Input – You give it this ◦ Process Data – It “Thinks” about it ◦ Store Data – You tell it to Store the info ◦ Output Data – It displays information on a monitor or other external device (maybe speakers?)

◦ Accept Input ◦ Process Data ◦ Store Data ◦ Output Data ◦ And a few other things like actually thinking for himself/herself

 Computers give us access to resources that are helpful  Computers Can Store More Data than we could possibly imagine  Computers can do computations much faster than we could ever dream of

 Sabotage the security of Governments' Computers  Get Access to Missile Codes  Have a massive assault on the World  The humans would win with some stroke of luck, or help from some guy named John Connor

Computers are stupid They just do what they are told So what does this mean? The Computer Makes No Errors Most Computer Problems are Software Related But there are occasionally Hardware problems that must be addressed

 Hardware – The physical components  Software – the programs or lists of instructions  Microsoft Word is a Software Application  The Computer’s Monitor is a piece of hardware

 2 Types of Software ◦ System Software  Operating System  Anti-virus  Utilities  Programming Languages  Device Drivers ◦ Application Software  Microsoft Word  Paint  Browser  Most everything is application software

 Operating System – the software that is responsible for the environment of operation  Technical Definition - it controls the I/O or input/output, the flow of data from microprocessor to memory to peripherals.  Examples ◦ OS X ◦ Unix ◦ Linux ◦ Vista ◦ XP

 Architecture or configuration is the design of the computer. ◦ As in, what does the computer consist of?  Specification is the technical detail about each component. ◦ As in, how big is the monitor?

 DVD Burner  DVD+R 16x, DVD-R 8x, DVD+-RW 8x, DVD+R DL 4x, DVD-R DL 4x  Pentium 4 Processor 2.99Ghz 1mb L2Cache  Pentium 4 Processor

The hardware, software, and you work together to complete tasks.

The categories of computers are:  Personal or microcomputers ◦ Desktop ◦ Notebook, Laptop, Tablet PC  Hand-help or PDAs  Mainframes ◦ are used by companies to provide centralized storage, processing, and management for large amounts of data.  Supercomputers ◦ are the largest and fastest of computers, and can process an enormous volume of data

 Mainframes ◦ are used by companies to provide centralized storage, processing, and management for large amounts of data. ◦ Mainframes are for LARGE AMOUNTS OF DATA and RELATIVELY FAST PROCESSING – USED FOR BUSINESS  Supercomputers ◦ Largest and Fastest Computers ◦ Supercomputers are for LARGE AMOUNTS OF DATA AND FOR VERY VERY FAST PROCESSING – USED FOR SCIENCE

Some input devices are: Keyboard Mouse Trackball Track point Touch pad Wireless pointer Joystick Microphone Webcam Keyboard Cordless mouse

 Monitors ◦ LCD ◦ CRT  Printers  Force-Feedback Joysticks

 Multimedia devices are peripheral devices that include text, graphics, sound, animation, and video. Examples:  Video Cards  TV Tuners  Sound Cards  Speakers  Microphones  Web Cam

 How is all of this possible?  Computers interpret commands as a series of 1’s and 0’s  On – 1  Off – 0  1 Bit is 1 on or 1 off  8 bits make a byte  What’s half of a byte?

 Know the approximations below  Kilobyte – 2^10 bytes (approximately 1000 bytes)  Megabyte - 2^20 bytes is a megabyte (approximately 1 million bytes)  Gigabyte – 2^30 bytes (approximately 1 billion bytes)

 In what movie did a white haired scientist say the prefix Giga completely wrong?  The Answer The Answer

 Brain – micro-processor (processor or CPU for short) ◦ Ever see on computer specifications something like the following?: 515 Intel Pentium 4 Processor 2.99Ghz  Short-Term Memory – RAM (random access memory) ◦ Ever see on computer specifications something like the following?:1GB PC3200 DDR SDRAM memory  Long-Term Memory – HDD (hard disk drive) ◦ Ever see on computer specifications something like the following?: 120 GB 7200 RPM Serial ATA hard drive  Which 2 of these 3 effect price the most?

 Backbone (and Central Nervous System) ◦ Motherboard  Eye ◦ Webcam  Ears ◦ Microphone  Voicebox ◦ Speakers

 Its speed is determined by: ◦ Clock speed –Ghz or Mhz ◦ Word size – 32 Bit Processor or 64 Bit Processor? ◦ Cache size – Faster than RAM memory that helps with processing, usually on the CPU chip or right beside it

 Memory refers to RAM (Short-term Memory) ◦ Memory in a computer is Volatile  Storage refers to “Persistent Data” ◦ Hard Disk Drives ◦ Flash Drives ◦ Floppies ◦ Tape Drives

There are four types of memory: ◦ Random access memory (RAM) ◦ Virtual memory (paging) ◦ Read-only memory (ROM)  is the permanent storage location for a set of instructions the computer uses. ◦ Complementary metal oxide semiconductor memory (CMOS)  semi-permanent information about where essential software is stored.  Used For BIOS

A storage device receives data from RAM and writes it on a storage medium. Later, it can be read and sent back to RAM.

Some common magnetic storage devices are: Floppy disks Hard disk drives Tape drives (good for archival purposes) Zip drives A floppy disk

 CD  DVD  HD DVD  Blu-ray  +R or -R Denotes Recordable Disk  +RW or –RW Denotes Rewritable Disk  + DL or –DL Denotes Dual Layer (Higher Capacity) Disk

USB (Universal Serial Bus) ports replace numerous connectors with one plug and port combination. (The port that thumb drives use) Peripherals - a piece of computer hardware that is added to a host computer (any hardware that isn’t in the computer) – Mouse is an examplecomputer hardwarecomputer Data bus – the data connections on the motherboard that allow communications between devices and all components of the computer

 A client/server network is a network with a file server. A file server acts as the central storage location. (The WWW)  A network without a file server is a peer-to- peer network. All of the computers are equal.

 LAN – Local Area Connection (home network, or small business network)  WAN – Wide Area Network ◦ any network whose communications links cross metropolitan, regional, or national boundaries ◦ Ex: The World Wide Web  PAN – Personal Area Network (bluetooth, short range)  MAN – Metropolitan area network ◦ Network spanning a city

Each computer that is part of the network must have a network interface card and network software. Then it becomes a workstation. Any device connected to the network is called a node.