1. Development
A computer is a machine capable of high speed processing and electronic storage of all kinds of information, it is one of the 20th century, mankind's greatest technological invention. Computer information as the most important tool of the 21st century, are increasingly deep into every corner of our work and life.
In 1946, the United States was born the first modern digital computer (Electronic Numerical Integrator and Calculator, ENIAC) in the world.
In 1981, IBM introduced the IBM-PC in the future, the development of computers has opened a new era - the era of microcomputers. The past 30 years, the microcomputer with its own characteristics, its use quickly spread to all areas of industry, agriculture, tertiary industry and other production and living, learning, most people use every day to become the type of computer.
2. Composition
The microcomputer (Micro-Computer) referred microcomputer refers to a microprocessor (Micro-Processor) core, accompanied by the production of large scale integrated circuit memory, an input / output (I / O) interface circuitry and a system bus consisting of computer. The microcomputer system structure and working principle are the same as other models comply with the von Neumann architecture requirements, by the arithmetic unit, a controller, a memory, an input device and an output device 5 hardware components.
From the host microcomputer, a display, a keyboard, a mouse, desktop and laptop computers the appearance shown in Figure 1-1. Wherein the internal hosts include motherboards, memory, hard drive, optical drive, video card, sound card, etc., shown in Figure 1-2.
FIG between the three microprocessor, microcomputer, a microcomputer system shown in FIG. 1-5 relationship.
2.1CPU
Functionally, the controller and the calculator are closely related but independent computer system of two components.
In the hardware implementation, the controller and the operator usually and any number registers into a single LSI chip, referred to as a central processing unit (Central Processing Unit, CPU). It is the arithmetic logic unit (ALU), an accumulator and general purpose registers, program counter, the timing and control logic and an internal bus means and so on. 1-3 as a microcomputer CPU Intel Core 2 Quad external view of the chip, which is slightly larger than the size of a matchbox.
CPU very fast growth rate, CPU type is different in different periods, 8086,80286,80386,80486 from early to mid-the Pentium (Pentium), PentiumⅡ, Pentium Ⅲ, to today's Pentium 4, dual-core, multi-core, etc. , through many generations of improvements.
2.2 microcomputers
The microprocessor does not work independently, and have respective memories, input / output interface circuit, and with a system bus, a microcomputer configured to run the program. Connecting these components requires a separate common carrier, which is the motherboard (Main Board), also known as master (Mother Board). CPU socket integrated on the motherboard, chipset, system bus, input / output (I / O) controller chip, memory sockets, the input / output system, an expansion card socket, power interface, shown in Figure 1-2. Other components directly plugged on the motherboard, or connected to the motherboard via a cable wire.
The microcomputer is plugged into the host CPU, a memory, an input on the same motherboard / output interface circuit, and a system bus integrally formed. Wherein the memory for storing programs and data. The input / output interface circuit is connected between the external device and CPU and a memory. The system bus provides a CPU address, data and control channel information to memory and interface circuitry, typically including a data bus (DB), an address bus (AB) and a control bus (CB). The microcomputer 1-4 as the host structure.
2.3 micro-computer system
The microcomputer system is mainly of a microcomputer, with input / output devices, and software configuration.
The microcomputer system is a combination of software and hardware, computer software is not configured is referred to bare metal, it can not be used in practice. Hardware is the basis of computing functions, the software is the soul of hardware actions.
3. A microcomputer system performance
3.1 Performance Microprocessor
Performance microprocessor plays a very important role in the computer system performance. With the development of microprocessor technology, microprocessor performance evaluation from various angles, but the most basic evaluation or word length and speed of operation.
①. Word
maximum word length that is the number of bits of data the CPU can handle a calculator, it is a reflection of the computer system data processing capacity of important technical indicators. Common word size 8, 16, 32, 64 and the like. The longer the word length, the higher the calculation accuracy of the system, the data processing capability.
Word length corresponding to the width of the bus, in particular the width of the data bus system also reflect performance. Data bus width is only comparable to the CPU word length, in order to effectively play the CPU data processing capability.
②. Computing speed
high and low speed operation is an important indicator to measure the performance of computer systems. Increase frequency to increase CPU speed is essential. The higher frequency CPU clock speed faster operation. Frequency unit is GHz.
Another unit reflects the computer system operation speed is MIPS, that is able to execute millions of instructions per second. As can be seen, the larger the value, the faster the speed of the computer.
3.2 Performance memory
The memory is a computer system memory device used to store programs and data. With the development of computers, the status of memory in the system is more and more important.
The memory has three major performance index: speed, capacity, and cost per bit (the bit value). In general, the higher the speed, the higher the bit value; the greater the capacity, the lower the bit value, the greater the capacity, the speed will be lower.
Performance 3.3I / O device
Today, I / O devices varied, different devices have different evaluation. For common peripherals, which has the speed performance, resolution and color depth.