Computer Basics
1, the programming language : human-computer communication, communication media
2. Programming : Programmers expression with the computer can understand, to write down their logical thinking, the result is a pile of files programming
purpose of learning is to make computer programming in accordance with logical thinking people spontaneously went to work in order to integrate human liberation out of
3, the computer system :
(1) hardware: computer entity: a host, a hard disk, etc.
(2) software: a program having a composition of various special features
4, complete computer system:
application software
operating system,
computer hardware
5, the five components of the computer:
(1) operator: the computer system operation (logic and mathematical operations)
(2) Controller: The computer control system
controller operator + = CPU
CPU work: Fetch ---> Analysis ---> perform
execution of the software are executed by the CPU, all of the software will eventually be converted into CPU instruction set to perform
(3) the memory (I / O devices): a storage system of a computer
memory: is based on the electrical work, access speed, but to power loss data, temporarily stores
external memory: slow access speed, stored permanently.
(4) Input devices: keyboard, mouse, camera
(5) output devices: monitors, stereos, printers
6, the operating system: operating system is between the application software and hardware a bridge, coordination, management, control, controls the computer hardware and software
to start the application:
the premise: to start the operating system
1. To start the file submitted to the operating system path
2. the path of the operating system files to the hard disk data read into memory
3. the CPU calls the operating system program code just read into the memory is performed
7, CPU instruction set:
cpu is the computer's brain, the brain integrates a series of instructions that control other body organs specific set of things, so stand pure hardware point of view, all the other components of computer instructions issued by the cpu control.
The purpose is to control the programming of computer hardware work, programmer's code are converted to a set of instructions to the cpu to control other hardware, the programmer is achieved by directly controlling the cpu indirect control other hardware objects. Is stored in the memory programmer's instructions / code, after removing from memory the instructions to be translated into cpu own instructions to perform, i.e., cpu at the factory on the integration of a series of internal instruction set, the instruction set is the soul cpu .
8, programming languages Category:
1. Machine Language: preparation of a binary instruction, direct control of the hardware
Advantages: high efficiency
Cons: Very low development efficiency
2. Assembly: instead of binary instructions in English labels, but also the essence of the direct control of the hardware
Benefits: efficiency is slightly lower relative to machine language
Cons: slightly higher development efficiency relative to machine language
3. Advanced Language: use human characters to write programs, the computer can not understand the human character, must be translated, translated into machine language the computer can execute.
Compiled: Similar to Google translate, compile once, to get the results can be executed repeatedly without recompilation, such as c, c ++, go
Advantages: high efficiency
Disadvantages: low efficiency of development, cross-platform poor
Interpreted: similar simultaneous interpretation line one line, i.e., translate and execute, as python
Advantages: development of high efficiency, cross-platform high
Disadvantages: execution efficiency is slightly lower than compiled
Summary:
1, efficiency: Machine Language> Assembly language> high-level language (compiled> interpreted)
2, the efficiency of development: high-level language (interpreted> Compiled)> Assembly language> machine language
3, cross-platform: Interpreted stronger than compiled
Notes: Notes is an explanation of the code, to enhance readability of the code, the content of the comment will not be treated as the code runs, code comments divide single and multi-line comments