Computers for Today Jason Fan
What is a Computer? A computer is a device that: • Accepts input • Processes data • Stores data • Produces output
What is a Computer? A Computer System is made up of: • Hardware—the physical components • Software—the programs or lists of instructions • Peripherals—the additional components
What is a Computer? 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?
How a Computer Works The hardware, software, and you work together to complete tasks.
How a Computer Works The data you type into the computer is called input. The result of the computer processing your input is called output.
Types of Computers The categories of computers are: • Personal or microcomputers • Desktop • Notebook, Laptop, Table PC • Hand-help or PDAs • Mainframes • Supercomputers
Types of Computers Personal computers are used for general computing tasks and fit the needs of most users
Types of Computers Hand-held computers fit in the palm of your hand and run on batteries.
Types of Computers Mainframes are used by companies to provide centralized storage, processing, and management for large amounts of data.
Types of Computers Supercomputers are the largest and fastest of computers, and can process an enormous volume of data.
Computer Hardware Computer hardware includes: • Input devices • Output devices • Processing hardware • Storage devices and media
Computer Hardware Some input devices are: • Keyboard • Mouse • Wireless pointer • Touch pad • Track point Cordless mouse
Computer Hardware Output devices are: Monitors and Printers are common output devices. CRT monitors and LCD (or flat panel display) monitors are two types of monitors.
Computer Hardware Factors that influence a monitor’s quality are: • Screen Size • Resolution • Dot Pitch
Types of Printers include: • Laser • Ink-jet • Dot Matrix
Computer Hardware • Multimedia devices are peripheral devices that include text, graphics, sound, animation, and video. • Speakers and sound cards are common multimedia output devices
Computer Hardware • The most important computer function is data processing. • Processing hardware is used to process data.
Processing Hardware • Computers interpret every signal as “on” or “off.” • 1 (“on”) and 0 (“off”) are referred to as bits. • Eight bits is a byte. Each byte represents a unique character.
Data Representation Storage and memory capacity is the amount of data the storage device can handle. • Kilobyte (KB) is about one thousand bytes • Megabyte (MB) is about one million bytes • Gigabyte (GB) is about one billion bytes
Processing Hardware • The two most important components of personal computers hardware are the microprocessor and memory. • These two factors directly affect the computer’s price and performance.
The Microprocessor • The microprocessor is a silicon chip designed to manipulate data. • Its speed is determined by: • Clock speed • Word size • Cache size
Memory Computer memory is a set of storage locations on the motherboard. There are four types of memory: • Random access memory (RAM) • Virtual memory • Read-only memory • Complementary metal oxide semiconductor memory (CMOS)
Memory RAM is temporary memory that is constantly changing while the computer is on. Virtual memory is extra memory that simulates RAM if more is needed.
Memory Read-only memory (ROM) is the permanent storage location for a set of instructions the computer uses. CMOS memory is semi-permanent information about where essential software is stored.
Memory A storage device receives data from RAM and writes it on a storage medium. Later, it can be read and sent back to RAM.
Storage Devices Data is stored as files. Executable files tell computers how to perform specific tasks. Data files are created by the user, usually with software.
Storage Devices Files are kept on storage devices. There are: Magnetic storage devices and Optical storage devices.
Storage Devices Some common magnetic storage devices are: • Floppy disks • Hard disk drives • Tape drives • Zip drives A floppy disk
Storage Devices Some common optical storage devices are: • CD-ROM drives • DVD drives • CD-R drives • CD-RW drives
Storage Devices CD-ROMs are for “read-only” access. CD-Rdrives allow you to record data on a CD-R disk. CD-RW drives allow you to write data on a CD-RW disk and access and modify data.
Data Communications Data Communications is the transmission of text, numeric, voice, or video data from one computer to another.
Data Communications The four essential components of data communications are: • Sender • Channel • Receiver • Protocols
Data Communications A sender is the computer that originates the message. The message is sent over a channel, such as a telephone.
Data Communications The receiver is the computer at the message’s destination. Protocols are the rules that establish the transfer of data between sender and receiver.
Data Bus The data bus is the communication between microprocessor, RAM, and the peripherals.
Data Bus An external peripheral device has a port or cable that connects it to the computer. Each port connects to a controller card, which plugs into expansion slots. The transmission protocol is handled by a device driver.
Data Bus Microcomputers have several types of ports: • Parallel • Serial • Small computer system interface (SCSI) • Musical instrument digital interface (MIDI) • Universal serial bus (USB)
Data Bus A parallel port transmits data eight bits at a time, and is often used to connect a nearby printer.
Data Bus A serial port transmits data one bit at a time, and often connects a mouse, keyboard, or modem.
Data Bus A SCSI (“scuzzy”)connection can allow many devices to use the same port, and are popular on Macs and notebooks. MIDI cards are used to record and play back musical data.
Data Bus Computer expansion ports
Data Bus USB (Universal Serial Bus) ports replace numerous connectors with one plug and port combination. The device you install must have a USB connector.
Networks A network connects one computer to other computers and peripherals. In a local area network (LAN), computers and peripherals are close to each other.
Networks A client/server network is a network with a file server. A file server acts as the central storage location. A network without a file server is a peer-to-peer network. All of the computers are equal.
Networks 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.
Telecommunications Telecommunications is communicating over a telephone. In the telecommunications process, the modem converts digital signals to analog signals at the sending site and a second modem converts them back at the receiving site.