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First, what is the programming language
Programming language is communication between man and computer media
Second, what is the programming
Programming is programming language and computer communication, let us work to help computer
Third, why should Programming
Let the computer help humanity work through slavery computer, freeing up labor
Four, five computer composition and respective roles
1, CPU: equivalent to the human brain, so as to control and calculation computer
CPU includes a controller and a computing unit
- The role of the controller: controls all computer hardware
- The operator action: logical and arithmetic operations
2, memory
- The role of memory: hardware devices in the computer temporarily store data
- Pros: Fast
- Disadvantages: temporary storage, power disappears
3, external memory
- The effect of external memory: a computer hardware devices permanently stored data
- Advantages: large capacity, permanent storage
- Cons: Slow
4, the input device
- Action: input information and content, such as a keyboard, mouse, U disk
5, the output device
- Action: output information and content, such as display, printer, U disk
Note: both an input device such as U disk is an output device, called IO device
https://www.cnblogs.com/nickchen121/p/10721884.html
Fifth, the mechanical hard disk works
Mechanical hard mechanical arm consists of three parts, tracks, sectors
Mechanical hard disk: reading data
Track: storing data
Sector: dividing the track, are usually divided into units of 512KB, a partial disk composed of a plurality of sectors
Average seek time: Robot find the time to track, due to industrial level, the average seek time is generally 5ms (solid-state drives do not have this time)
Average latency: Robot find the time data on the track, due to the uncertain position data need to be scanned from head to tail hard to find data
Hard to 7200r / min for example:
Find the data in the hard disk head time 0ms
Find the data in the hard disk Tail time:
7200r/min=120r/s
1/120=0.0083s/r=8.3ms/r
（0+8.3）/2=4.15ms/r
Therefore, the average delay time of 4.15ms (solid-state drives do not have this time)
Find data = average seek time + average latency. 5 + 4.15 = 9.15ms =
https://www.cnblogs.com/nickchen121/p/10715496.html
Six, QQ start the process
1. Double-click the icon QQ, pointing to a path of external memory, go to this location to find QQ content
2.CPU send commands to the memory, so memory read QQ content of external memory
3. Run the QQ code in memory
4.QQ start
https://www.cnblogs.com/nickchen121/p/10721933.html