1. a complete computer system has three components
Applications, hardware, operating system (OS) and computers.
2. The five components of the computer
Consisting of five computers includes: a controller (CU), arithmetic unit (ALU), memory (Memory), input devices (Input) and an output device (Output).
CU is the main control system, ALU function is the mathematical and logical operations;
CPU = ALU + CU.
In the body's organs, similar to the human brain. Memory equivalent to the human memory (temporary access), while the hard disk is equivalent to a person's notebook (permanent preservation).
The memory is divided into memory and external memory.
Advantage of the memory access speed is faster compared to the hard drive; disadvantage is that power data is easy to lose, not recorded.
Advantage of the hard disk is the off external memory data is not lost, permanent preservation; disadvantage as compared with the memory access speed is slower.
Input devices: keyboard, mouse, touch screen
output devices: monitors, stereos, printers
Input and output devices collectively referred to as I / O.
3. The three core components of a computer
CPU, memory and hard drive.
4.CPU workflow
Select memory read command parse commands can be translated into their operational steps corresponding to the control hardware execution
of computer instructions into simple instruction set (RISC) and complex instruction set (CISC) two kinds.
Processing computer word length is divided into 32-bit and 64-bit. CPU backward compatible, so-called compatibility is that 64-bit CPU can be perfectly compatible with 64-bit applications and 32-bit software, application software, on the contrary, the 32-bit CPU can only run 32-bit applications software, word processing or because of insufficient crash program software.
5. Memory
There are many reservoir, including registers, cache, memory, hard disk and tape.
Hard disk and solid state drives into mechanical keyboard.
A memory unit conversions. 8bits = 1Bytes; 1024Bytes = 1KB; 1024KB = 1MB; 1024MB = 1GB; 1024GB = 1TB; 1024TB = 1PB.
When a user starts a computer, the computer first enters the BIOS mode, BIOS is stored in ROM of the computer, select the device BIOS to start by reading a CMOS configuration, installed in the hard disk to initiate the operating system to control computer's hardware.
The operating system also essentially an application.
6. Operating Systems
OS: refers to the hardware and software resources to control and manage the entire computer system, and a reasonable allocation of computer resources, to provide convenient user interfaces and other software environments and procedures for the collection.