Computer Basics of programming - Outline

Computer Basics of programming

What is the programming language

The programming language is the language of nature, human and computer communication medium

What is programming

Write a bunch of files in a programming language

Why Programming

Slave computer, instead of labor

Composed of five computer

Less need for <Principles of Computer Organization>, development

CPU (brain)

Controller

Control hardware

Operator

Arithmetic logic operations +

RAM

Storing data

Pros: Fast

Cons: off disappears, small capacity

External memory

Storing data

Advantages: large capacity, permanent storage

Cons: Slow

input device

Input information, such as a keyboard / mouse / U disk

Output Device

Output information, such as the display (the display color is controlled) / printer / U disk

u disk is the IO devices

32 and 64

The computer reads the data size of a one-time, he has downward compatibility

Application process starts

1. Double-click qq (qq find a path) Users -> operating system -> CPU
2. CPU control, after finding qq content from external memory is read into memory
3. Run qq

Mechanical hard disk works

Robot: read data

Track: storing data

Sector: dividing track

Average seek time: 5ms

Average delay time: 7200r / s 4.15ms

The average seek time data: 9.15ms

Computer operating system

What is the file

The operating system provides a virtual unit

What is the application procedure

A bunch of files

What is the role of the operating system

The complex instruction computer hardware interaction simplification

The computer which is divided into three layers

Hardware: Operating System

Operating system: hardware / application / user

Applications: Operating System

User: Operating System

Operating system boot

1. Power, power
2. Start temporary operating system
3. Temporary operating system to start the real operating system

Programming Language Category

Machine language

0 and 1

Pros: fast execution efficiency

Disadvantages: low efficiency of development

Assembly language

Write English symbols

Advantage (compared to machine language): the development of high efficiency

Disadvantages (compared to machine language): Low efficiency

High-level language

Compiled language (Google translation)

C / Java

Advantage (interpreted language): high efficiency

Disadvantages (compared to interpreted languages): low development efficiency

Compiler: written in assembly language

Interpreted languages ​​(simultaneous interpretation)

Python

Advantage (compared to a compiled language): the development of high efficiency

Disadvantages (compared to a compiled language): Low efficiency

Interpreter: c / java to write

Network bottleneck effect

The implementation of a program, c may 0.0000001ms (operating system, non-network transmission uses language c), python1ms, but the network transmission 10ms

Python implementation of the program in two ways

hello world

Interactive (jupyter)

Pros: Run an implementation of a

Disadvantages: Close disappear

Command line (pycharm)

Pros: has been saved

Disadvantages: all finished before they can debug bug

Although txt file can run, but try to use py file

Later try to use pycharm or jupyter