The Computer and Information Systems
Dr Yingchao ZHAO
After this lecture, you should be able to:
Describe the different components of an information system
Describe the different types of computers.
List out the different basic components in a computer.
Understand the basic types of memory .
We are surrounded by various kinds of computers nowadays
A computer is an electronic device , operating under the control of instructions stored in its own memory.
A computer can accept data, process the data according to specified rules, produce results, store results for future use, and communicate results with others.
Computers process data into information.
Raw, unprocessed facts, including text, numbers, images, audio, video, etc.
Data that have been collected and processed into a meaningful form helps decision making
People – End users
Procedures – The rules or guidelines people follow when using software, hardware, and data are procedures.
Typically, these procedures are documented in manuals written by computer specialists.
Software – A program consists of the step-by-step instructions that tell the computer how to do its work. Software is another name for a program.
The purpose of software is to convert data into information.
Hardware – The equipment that processes the data to create information is called hardware.
Data – The raw, unprocessed facts, including text, number, images, and sounds are called data.
Automatic Teller Machine (ATM)
Bar-code system for retailing
Any more …..
Mobile computers and mobile devices
A personal computer can perform all of its input, processing, output, and storage activities by itself.
Two popular architectures
PC (Originated from IBM, usually uses Windows)
Apple (usually uses MacOS)
Small enough to be held in hands
Portable media player
A game console is a computing device designed for single-player or multi-player video games.
May be stationary or portable
A server controls access to the hardware, software and other resources on a network, to provide a centralized storage area for programs, data, and information.
A large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously.
Fastest, most powerful, and most expensive computers. http://www.top500.org/system/177975
A special-purpose computer that functions as a component in a larger product.
• Mobile and digital telephones
• Digital televisions
• Video recorders
• DVD players and recorders
• Answering machines
• Sprinkling systems
• Security monitoring systems
• Antilock brakes
• Engine control modules
• Airbag controller
• Cruise control
• Remote monitoring systems
• Power monitors
• Machine controllers
• Medical devices
Computer Devices and Office
Physical components hardware
• Allows you to enter data and instructions into a computer
Output Device • Conveys information to one or more people
• Contains the electronic components of the computer that are used to process data
• Holds data, instructions, and information for future use
• Enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices
Input devices – allow you to enter data and instructions into a computer
Keyboard, Mouse, Trackball, Card-reader, Barcode reader, Scanner, RFID reader, etc.
Output devices – conveys information to one or more people
Monitor, speaker, printer, projector, etc.
The system unit is a case that contains electronic components of the computer used to process data.
Main components inside the system unit on a desk-top personal computer include:
The motherboard is the main circuit board of the system unit, connecting all components.
A computer chip contains integrated circuits.
The processor, also called the CPU (Central Processing
Unit), interprets and carries out basic instructions that operate a computer.
Two main units inside a CPU,
Control Unit (CU)
Arithmetic and Logic Unit (ALU) by bfishadow
Have you heard about dual-core, quad-core, or multi-core CPUs?
The control unit (CU) is the component of the processor that directs and coordinates most of the operations in the computer.
The arithmetic and logic unit (ALU) performs arithmetic (e.g., +, -, *, /, etc.) and logical
(e.g., >, <, etc.) operations
The current trend of processor is to include more parallel processing units to execute more instructions at the same time.
Plan your use beforehand.
A port is the point at which a peripheral attaches to or communicates with a system unit.
Sometimes referred to as a jack.
A connector joins a cable to a port.
Cable from Wikipedia
A USB (Universal Serial Bus) port is one of the most commonly used port.
It can connect up to 127 different peripherals.
You can attach multiple peripherals using a single
USB port with a USB hub
Other popular ones include:
Firewire port eSATA port
A Bluetooth adapter converts a USB port into a Bluetooth port.
A smart phone may communicate with a notebook computer using an IrDA port
Expansion slots connect to expansion buses.
Common types of expansion buses include:
PCI Express bus
PC Card bus
The power supply converts the wall outlet
AC power into DC power.
Some external peripherals have an AC adapter, which is an external power supply.
Inside system unit
Processors can directly access the data inside main memory (RAM).
All contents are gone when the system is turned off.
Memory consists of electronic components that store
instructions waiting to be executed by the processor, data needed by those instructions, and results of processing of data
Memory usually also stores these things:
The operating system and other system software
Data being processed and the resulting information
Two types of memory in system:
Loses its contents when power is turned off
Does not lose contents when power is removed
ROM, flash memory, and CMOS
Three basic types of RAM chips exist:
RAM chips usually reside on a memory module , and are inserted into memory slots on motherboard.
The amount of RAM required in a computer often depends on the types of software applications you plan to use.
Cache memory are small, expensive, fast memory modules.
Frequently accessed instructions & data are
“cached” (stored in cache) to improve computer performance.
Some cache resides inside the processor chip.
ROM (Read-Only Memory) refers to memory chips that store permanent data and instructions.
E.g., BIOS, firmware
A PROM (programmable ROM) chip is a blank
ROM chip that can be written once.
EEPROM (Electrically Erasable PROM) chip can be erased and re-programmed.
It is important for us to know how to use computers nowadays.
Various types of computers are introduced.
Personal computers, Mobile devices, Mainframes,
Supercomputers, Game consoles, etc.
Functional components in the system unit of a computer are described.
Ports Buses Power supply