Computer hardware computer :( slaves)
1. The five major components:
Controller
Operator
Storage I / O: external memory Memory +
The input device input
Output device outinput
2.CPU
Operator + = CPU controller
Function: Controls the arithmetic +
Work: Fetch ----> analysis ---> Execute
Execution of the software are executed by the CPU, eventually all software should be converted into a cpu instruction set to perform
A binary become a bit: 111
cpu having downward compatibility
Key summary: cpu cpu data from memory function take x86-64
Complete computer system:
application
operating system
Computer hardware
What is the operating system:
Is a coordination, management, control program of computer hardware and software
Operating system into two parts:
Interface program: hardware features packaged into simple interface for the user to use the application software or to
Kernel: Specific control hardware, the next
Kernel mode and user mode (Learn)
Two operating states of cpu
User mode: cpu execution status of the program / application is located, is in the user state can not control hardware
Kernel mode: performing cpu state in which the operating system kernel, the kernel mode can be controlled in hardware
Start the application: (emphasis !!!)
Premise: First start the operating system
1, start the path to the file submitted to the operating system program
2, the operating system according to the file path of data to the hard disk into memory
3, the operating system calls cpu to execute program code in memory just read
Programming languages Category:
Machine language : binary instruction programming
Advantages: high efficiency
Disadvantages: low efficiency of the development of high learning curve
Assembly language : instead of binary instructions in English labels, but also the nature of the hardware directly
Advantages: high efficiency
Disadvantages: low efficiency of the development of high learning curve
High-level language : use human characters to write programs, the computer can not understand the human character, must be translated, translated into computer language computer to perform
Compiled: c
Similar to Google Translation -> gcc -------> machine language
Features: compiled once, to get the results can be executed repeatedly without recompilation
Translation: The program -----> gcc -----> machine language
Execution: machine language ------> CPU
High efficiency advantages ::
Disadvantages: cross-platform debugger trouble poor
Explanatory: Python,
Simultaneous interpretation is similar to -> interpreter
Features: explain a line, one line, that is, translate and execute
Program ------> interpreter ----> machine language ------> CPU
Advantages: Cross-platform development of high efficiency and high debugger convenience
Disadvantages: low efficiency
to sum up:
Learning Difficulty: high to low
Efficiency: high to low
Development Efficiency: from low to high
title:
1 to 6 into
Number one title: the content space #
python environment to build
pycharm environment to build
print("hello world")
Block `` `python + Enter (a separate line, to switch input English)
print("hello world")Copy = ctrl + c
Paste = ctrl + v
My thick black bold content ** **
I am inclined italic * content *
I am inclined thick and bold content with Diagonal * * * * * *
388 Strikethrough "Content ~ ~ ~ ~"
| Full name | age | Occupation |
|---|---|---|
| Alex | 88 | it |
Insert Hyperlink
Baidu [content] + (URL) hyperlink #
Direct drag
Ordered: Digital Space
1. + Space
Disorder:
Minus + Space
- Black dots (minus + space) + Tab
- Use tab to enter the next level
Return to the previous shift + tab
- [X] Hello - + + space [space] + space
Escape: 7 * 8 * 9
Python interpreter environment variable installation and configuration procedures
www.python.org Downloads page to download the appropriate version
Download the complete installation
After installation is complete configuration environment variable
Right-click on My Computer -> Properties -> Advanced System Configuration on the left side -> Environment Variables -> System Variables below to find Path
(
)
Click New to enter the python path
CTRL + R punch operation, the input into the terminal cmd, type python carriage return the following results:
