Know how to find data from multiple sources, select relevant materials, analyze and organize them into a form that can be used for decision-making.
Computers have become a tool for people to access and manage information.
An information technology expert is a person who analyzes and designs tools.
What is a computer?
The traditional definition of computer includes
A machine that accepts data and processes it into useful information.
A computer is a binary, digital, electronic machine that stores programs.
Although computers are usually digital machines, there are also analog machines.
An electronic device, which operates under the control of instructions stored in its own memory, can accept data (input), process data arithmetically and logically, generate processing results (output), and store the results for future use. Many computers receive and send data (communication) through local area networks and wide area networks.
A computer system consists of hardware and software.
What is hardware?
Hardware appliance
Hardware is a physical device or component that can be physically processed-you can use it.
input device
Input devices convert data collected by human beings into coded electrical signals that can be processed by computers.
cpu
Electronic processing takes place in the central processing unit. The central processing unit includes
A control device for controlling all functions of a computer
An arithmetic and logic unit (ALU) that performs any calculation.
memory
Memory holds all programs and
What is currently open in RAM?
Data (comments)
word processor
O.S
output unit
The output device converts the electronic signal of the computer back to information.
Auxiliary storage device
These devices permanently store programs and data. Programs and data are not necessarily (or may be) currently in use. Such as DVD discs
Communication equipment
These devices enable one computer to connect to another.
List six different types of hardware?
Auxiliary memory (external), input, processor, output, memory, communication.
Name eight kinds of hardware
USB, keyboard, monitor, screen, RAM, ROM, VDU, modem.
System units and peripherals
The system unit is the computer case.
Peripheral equipment refers to any equipment outside the machine, or in other words, any equipment plugged into the back of the machine. Peripheral devices include keyboards, mice, printers, joysticks and other devices.
Peripheral equipment refers to any equipment outside the machine, or in other words, any equipment plugged into the back of the machine. Peripheral devices include keyboards, mice, printers, joysticks and other devices.
What else does the computer have?
software
Software is a computer program, which is a set of detailed instructions to guide the computer to perform the tasks necessary to process data into information. These instructions are written in a language that computers can understand. Software includes computer games, word processing software packages, accounting software packages, etc.
Definition of computer system
Computer system is the configuration of hardware and software, which work together to process data into useful information to achieve the purpose of human users.
What is data?
Data is the original fact that can be input into the computer, which can be numbers, words, images and sounds.
For example, Mary
The name is a piece of data
What is information?
Information is processed data that is meaningful and useful.
John is gay.
A list of people who got an A in an exam
John a
Chai a
Pam a
For example, $23,500 for Commodore.
Magna $265,438+0,500
Falcon $ 19 800
The system unit includes
motherboard
cpu
memory
Other electronic products
It is the place where computer program instructions are executed and data are processed.
processor
cpu
The CPU interprets and executes the basic instructions for operating the computer, and the CPU includes
Control unit and
arithmetic logic unit
Control unit
The control unit directs and coordinates the operation of the computer.
For each instruction, the control unit repeats four basic operations,
charming
decode
carry out
take care of
CPU speed
The speed of CPU can be measured by MIPS.
The number of millions of instructions per second
Arithmetic/logic unit
The ALU performs all calculations, including
Arithmetic operation 2+3
Comparative operating age>= 17
Logical operation pass
Processing instruction
The CPU can start executing the second machine cycle before completing the first machine cycle, which is called pipelining.
Current CPU can pipeline up to 4 instructions.
Storage in CPU
Registers temporarily store data and instructions.
Computer clock
The system clock is a necessary condition to control the operation time of all computers.
Each tick of a clock is called a clock cycle.
Clock speed is the speed at which the processor executes instructions.
Hertz is one cycle per second, megahertz is 1024 times 1024, and gigahertz is 1024 times 1024 times 1024.
memory
Memory is a temporary storage place for data and (program) instructions.
Memory is based on
Kilobytes 1024 bytes 2^ 10/0
Megabytes 1024* 1024 bytes 2 20
Gigabyte1024 *1024 *1024 bytes 2 30
Data representation
A digital computer is made up of many small electronic circuits. Each circuit can be closed or opened at any time.
Therefore, these devices are called binary devices.
Binary digits 0 and 1
Each off or on digital value is called a bit, which is the abbreviation of binary number.
A 1 bit computer can distinguish two values-characters, symbols or numbers. Almost not enough for the characters on the keyboard.
Bit character
1 2
2 4
3 8
4 16
5 32
6 64
7 128
8 256