Python Job 1

I. The role of programming languages and their relationship to operating systems and hardware

1. Programming language is the language of communication between programmers and computers. The advent of the operating system is to run on the hardware, to control the hardware, when we develop, we only need to invoke the operating system to provide us with a simple and elegant interface can be

Two. cpu-"Memory-" disk

2.CPU just like the human brain is responsible for computing the memory responsible for the temporary storage of the hard disk is responsible for permanent storage

Three. CPU and register,

3. The brain of the computer is the CPU, which takes instructions--------from memory. It takes much longer to access the memory to get instructions or data than the CPU executes instructions, so there are registers inside all CPUs that hold the key variables and temporary data.

Four. kernel state and User Configuration and how to switch

4. System calls

Five. Memory series, L1 cache, L2 cache, memory (RAM), EEPROM and Flash

5. The computer cache is a pre-extracted computer instruction that is stored to increase the speed at which the computer extracts instructions. L1 reads faster than L2, but L1 is much smaller than L2.

Rarom and Ram refer to the semiconductor memory, ROM can still hold the data when the system stops powering, and Ram usually loses data after power-down, the typical RAM is the memory of the computer.

Six. CMOS and BIOS battery

6.CMOS refers to a memory chip on the motherboard that can read and write. It stores the microcomputer system clock information and hardware configuration information, a total of 128 bytes. When the system is power-on, the CMOS information is read to initialize the state of each part of the machine. It is powered by a system or backup battery, and the power off information is not lost.

The function of the BIOS battery is to continue powering the BIOS module on the motherboard after the computer shuts down to save BIOS setup information.

Seven. 1 disk structure, 2 mean seek time, 3 average delay time, 4 virtual memory vs. MMU

1. Hard disk structure: Head, track, cylinder, Sector, Disc 2: Average seek time refers to the MO Magnetic CD-ROM machine after receiving the system instruction, the head from the beginning to move to the track of the data to be moved to the average time required, it refers to the computer issued an address command, to the corresponding target data is found the time required in milliseconds Ms

3 Average delay time: refers to the average amount of time the drive takes to move from the beginning to the track where the data is moved after receiving the system instruction.

4 Virtual Memory: Virtual memory is a technology of computer system memory management. It allows the application to assume that it has contiguous available memory (a contiguous, complete address space), and in fact, it is usually separated into multiple physical memory fragments, and some are temporarily stored on external disk storage and exchanged for data when needed.

MMU: It is the control line used by the central processing unit (CPU) to manage virtual memory, physical memory, and also responsible for mapping virtual addresses to physical addresses, as well as providing a hardware mechanism for memory access authorization

Eight. Tape

In the case of the same price than the hard disk has a higher storage capacity, although the speed is lower than the disk, but because of its large capacity, in the earthquake flood fire, the characteristics of strong mobility, often used to do backup.

Nine. Device driver and Controller

1. Device Driver "is a computer and equipment to communicate the special program, can say the equivalent of hardware interface, the operating system only through this interface, to control the work of hardware devices

2. Controller: is to find a chip on the motherboard or a group of chips (hard disk, network card, sound card, etc. all need to plug into a mouth, the port is the controller), the controller is responsible for controlling the connected device, it receives commands from the operating system, such as reading hard disk data, and then the hard disk device initiates read requests to read the

10. Bus with South Bridge and North Bridge

Bridge, PCI: Connecting high-speed equipment

ISA bridge: Connecting slow devices

11. Operating system start-up process

bios–>mbr->; Pbr–>os files

12. Application Start-up process

Operating system HDD "memory" execution

Python Job 1