Fourth-generation computer

electronic components

The fourth-generation electronic computer is based on large-scale, ultra-large-scale integrated circuits Electronic components.

Fourth-generation features

The fourth-generation computer refers to the use of large-scale integrated circuits (LSI) and very large-scale integrated circuits (VLSI) as the main electronic devices since 1970 Computer. For example, the 80386 microprocessor can integrate about 320,000 transistors on a single chip with an area of ​​about 10mm X 10mm.

Another important branch of the fourth-generation computer is microprocessors and microcomputers developed on the basis of large-scale and very large-scale integrated circuits.

Four stages

The first stage was from 1971 to 1973, and there were 4004, 4040, and 8008 microprocessors. In 1971, Intel Corporation developed the MCS4 microcomputer (CPU 4040, four-bit computer). Later, the MCS-8 model with 8008 as the core was introduced.

The second stage is the development and improvement stage of microcomputers from 1973 to 1977. There are 8080, 8085, M6800, Z80 microprocessors. The initial product is Intel's MCS-80 type (CPU 8080, eight-bit computer). In the later period, there were TRS-80 type (CPU is Z80) and APPLE-II type (CPU is 6502), which once swept the world in the early 1980s.

The third stage is the development stage of 16-bit microcomputers from 1978 to 1983. There are 8086, 8088, 80186, 80286, M68000, Z8000 microprocessors. The representative product of microcomputer is IBM-PC (CPU is 8086). The pinnacle products of this stage are Apple’s Macintosh (1984) and IBM’s PC/AT286 (1986) microcomputer.

The fourth stage is the development stage of 32-bit microcomputers starting in 1983. Microprocessors have successively introduced 80386 and 80486. 386 and 486 microcomputers are the initial products. In 1993, Intel Corporation introduced the Pentium or P5 (Chinese translation for "Pentium") microprocessor, which has a 64-bit internal data channel. Pentium III (also called P7) microprocessors have become mainstream products, and Pentium IV was launched in October 2000.

It can be seen that the performance of a microcomputer mainly depends on the performance of its core device-the microprocessor (CPU).

Appearance and development

The appearance and development of microcomputers that concentrate CPUs on a single chip set off a wave of popularization of computers. In 1969, Intel was commissioned to design a complete circuit for a calculator. Federico Fagin, a young engineer of the company, successfully integrated 2,250 transistors on a 4.2×3.2 silicon wafer. This is the first microprocessor-Intel 4004. It is 4 bits. After it, the 8-bit microprocessor Intel 8008 was born in early 1972. The second generation of microprocessors (8-bit) appeared in 1973, such as Intel 8080 (1973), M6800 (1975, M stands for Motorola), Z80 (1976, Z stands for Zilog Company) and so on. In 1978, the third generation of microprocessors (16 bits) appeared, such as Intel 8086, Z8000, M68000 and so on. In 1981, the fourth generation of microprocessors (32-bit) appeared, such as iAPX432, i80386, MAC-32, NS-16032, Z80000, HP-32, etc. Their performance is roughly comparable to that of large and medium-sized computers in the 1970s. The microprocessor's speed of changing from one generation to another in two or three years is unmatched by any technology.

Computer

One of the earliest personal computers was the Apple II computer from Apple Inc., which was sold on the market in 1977. Followed by TRS-80 (Radio Shack) and PET-2001 (Commodore). Since then, various personal computers have sprung up. Personal computers at that time were generally based on 8-bit or 16-bit microprocessor chips, with a storage capacity of 64KB or more, with input and output devices such as keyboards and monitors, and could be equipped with peripheral devices such as small printers, floppy disks, and cartridges. You can use a variety of high-level language self-programming.

With the continuous popularity of PCs, IBM also organized a personal computer development team in August 1979. Two years later, the IBM-PC was announced, and the expansion model IBM-PC/XT was introduced in 1983, which caused a great shock in the computer industry. At that time, IBM personal computers had a series of characteristics: advanced design (using Intel 8088 microprocessor), rich software (more than 800 companies use it as a standard to prepare software), complete functions (strong communication ability, and can be connected to mainframes) ), the price is cheap (production is highly automated, the cost is very low). By 1983, IBM-PC quickly occupied the market and replaced Apple, which was known as the king of microcomputers in the United States.