Python operating system

I. Hardware composition of the computer:

Motherboard: Curing Other Hardware (registers, is a hardware that interacts directly with the CPU)

CPUs: CPU: Performs calculations (digital and logical calculations) and controls (controls all hardware coordination efforts)

Storage: Memory, HDD

Input device: Keyboard, mouse, microphone, etc.

Output device: monitor, speaker, etc.

The early computers were computed as the core

Now the computer is stored as the core

First generation computer: Electronic tube computer, and its power consumption, large volume, heat dissipation is particularly high

Second generation computer: Transistor computer

Third generation computer: Integrated circuit computer (white head computer), one motherboard cured dozens of to hundreds of small hardware

Fourth generation computer: large integrated computer, one motherboard can cure 100,000 hardware

Fifth generation computer: Very large integrated circuit computer

Two. Computer operating system

The operating system is a software, a software that can directly manipulate the hardware

The Windows system was developed by Microsoft

When the computer was first used, there was no operating system.

The purpose of the operating system: to make it easier for the user to be beautiful, to achieve high availability, low coupling

The role of the operating system:

1. Encapsulates all hardware interfaces, making it easier for various contacts to use the computer

2. Reasonable scheduling and distribution of all resources within the computer

The development of the operating system:

1. Artificial system: Perforated cassette (everyone can enjoy all the resources in the computer for a certain period of time)

2. Offline era: Completely isolate people from machines

3. Single-channel batch processing system: Only one job is allowed in memory

4. Multi-channel batch processing system: Allow multi-channel operation in memory

5. CTSS: Divide the CPU execution time slice, each program takes the time slice as the unit executes

6. Real-time systems: Generally relatively rare, mainly used in military and industrial production

Three. Language history:

Machine language: The earliest machine can be directly recognized by the language, consisting of 0 and 1

Assembly Language: Instruction Languages

Advanced language: Process-oriented language (c), object-oriented language (c++,java,python,php, etc.)

Four. Process

A process is a program that is executing, a collection of commands, datasets, and so on during the execution of a program, or a process that can be called a process, which is a dynamic concept.

The process has three main components:

Code snippet

Data segment

PCB: Process Management control

Three basic states of a process:

Ready state: All resources required for the operation have been obtained, except CPU

Execution status: All resources have been obtained, including CPU, in a running state

Blocking state: For various reasons, the process abandons the CPU, causing the process to continue executing, at which time the process is in memory and continues to wait for the state of the CPU

Pending status: Refers to a process that has discarded the CPU for various reasons, causing the process to continue executing and the process being kicked out of memory. is a special state of the process

　　

Python operating system