What are the three commonly used operating systems?

Operating system is a platform for managing computer software and hardware resources. Without it, no computer can run normally. In the history of personal computer development, there have been many different operating systems, among which five are the most commonly used: DOS, Windows, Linux, Unix(Mac)/Xenix, OS/2. The development process and functional characteristics of these five microcomputer operating systems are introduced below. \x0d\ 1。 Since the DOS operating system \x0d\ of 198 1 came out, DOS has undergone seven major version upgrades, from the version of 1.0 to the current version of 7.0, with continuous improvement and perfection. However, the single user, single task, character interface and 16 bits of DOS system have not changed, so its memory management is limited to 640KB. \x0d\ DOS was originally developed as the operating system of IBM-PC, so it has low requirements for hardware platform. Even a high-end version like DOS6.0 can run normally under the environment of 640KB memory, 40MB hard disk and 80286 processor, so DOS system is suitable for both high-end and low-end microcomputers. \x0d\ There are three different brands of commonly used DOS, namely MS-DOS of Microsoft, PC-DOS of IBM and DR DOS of Novell. All three DOS are compatible, but there are still some differences. MS-DOS is the most used of the three DOS. One of the biggest advantages of \x0d\ DOS system is that it supports many general-purpose software, such as various language processing programs, database management systems, word processing software, spreadsheets and so on. Moreover, many application software systems have been developed around DOS, such as financial, personnel, statistics, transportation, hospital and other management systems. Because of this, although DOS can no longer adapt to the hardware system of 32-bit computers, it is still widely popular and will not be eliminated soon in the next few years. \x0d\ DOS system has expanded the vision of individual users and still occupies an important position in the industrial field. \x0d\ 2。 Windows system \x0d\ windows is the first generation of windows multitasking system released by Microsoft in June, 5438+09851/,which made PC enter the era of so-called graphical user interface. In the graphical user interface, each application software (that is, software supported by windows) is represented by an icon. Users only need to move the mouse to an icon and press the pick button twice in a row to enter the software. This interface mode provides great convenience for users and improves the use of computers to a new stage. \x0d\ windows 1。 X is a multi-window and multi-task version, but the hardware platform at that time was PC/XT, which was very slow, so windows 1. X is not very popular. At the end of 1987, Microsoft introduced version 2.x of MS-Windows, which has the function of overlapping windows, the window size can also be adjusted, and both extended memory and extended memory can be used as disk cache, thus improving the performance of the whole computer. In addition, it also provides many applications: text editing and writing, notepad, calculator, calendar? Wait a minute. Then, in 1988 and 1989, two versions of MS-windows/286-V2. 1 and MS-windows/386 V2. 1 were introduced. \x0d\ 1990, Microsoft introduced windows3.0, which further strengthened its functions, powerful memory management and provided a considerable number of windows application software, thus becoming the new operating system standard for 386 and 486 microcomputers. Subsequently, windows released version 3. 1, and launched the corresponding Chinese version. Compared with version 3.0, version 3. 1 added some new functions, which was welcomed by users and was the most popular version of windows at that time. \x0d\ 1995, Microsoft introduced windows95 (also known as Chicago or windows4.0). Before that, windows was all booted by DOS, that is to say, they were not completely independent systems, while windows95 was a completely independent system, which was further improved in many aspects and integrated with network functions and plug-and-play functions, so it was a brand-new 32-bit operating system. \x0d\ 1998, Microsoft introduced an improved version of windows95. One of the biggest features of windows98 is the integration of Microsoft's Internet browser technology into windows95, which makes accessing Internet resources as convenient as accessing local hard disks, thus better meeting people's growing demand for accessing Internet resources. Windows98 is the mainstream operating system currently in practical use. \x0d\ windows2000, windowsNT system (NT is the abbreviation of new technology), windowsNT is a real 32-bit operating system. Different from ordinary windows system, it is mainly for enterprise users, including server version and working version. 1999, Microsoft unified the latest workstation version NT 5.0 and common windows98 into a complete operating system, namely windows 2000 Professional. In this way, whether for enterprise users or ordinary individual users, Microsoft will have only one windows operating system in the future. \x0d\ windows XP, the core of windows NT-based system, is the most used and easiest operating system at present. Windows xp is divided into three main versions: Windows XP Professional, Windows XP Home Edition and Windows XP 64-bit Edition. This version of Windows XP Professional has all the functions of XP and is a full-featured version of XP. Windows XP Home Edition, also called Home Edition, focuses on the entertainment performance of the system. Windows XP 64-bit version is a 64-bit version of XP system. Because the new Vista has not been listed yet, a 64-bit system temporarily launched by Microsoft has not been popularized in the market because of the compatibility of software and hardware, and only some players are using it. Last year, Microsoft introduced a simplified version of windows se, but its function is not practical and its popularity is not high. \x0d\ Microsoft is currently stepping up research and development of the next generation windows system, code-named Vista. Vista has many exciting functions, including beautiful 3d effects, quick search function and so on. Due to various reasons, there are only a few test versions of Vista system at present, and the release date has been postponed again and again. At present, Microsoft released Vista system in 2007. \x0d\ III。 Linux system \x0d\ Linux is a dazzling name in today's computer world. It is the largest free software in the world at present, and it is an operating system equivalent to Unix and windows, with complete network functions. \x0d\ Linux was originally developed by Finnish Linus Torvalds, and its source program was publicly released on the Internet. As a result, it aroused the enthusiasm of computer enthusiasts all over the world. Many people downloaded the source program, perfected a function according to their own wishes, and then sent it back to the Internet, so Linux was carved into the most stable and promising operating system in the world. Someone once joked that if Bill Gates did the same for the source code of windows, many bugs (errors) left in windows would no longer exist, because computer enthusiasts all over the world would become voluntary testers and programmers of windows. \x0d\ At present, the most popular Linux system versions are Fedora Core, Redhat Linux, Mandriva/Mandrake, SuSE Linux, debian, Ubuntu, Gentoo, Slackware, Red Flag Linux and so on. Among them, Redhat Linux, commonly known as Little Red Riding Hood, is the most popular version of Linux system, and Red Flag Linux is a server operating system independently developed by China. Including Yahoo search, and most Linux servers in China are systems using Redhat Linux. \x0d\ Linux operating system has the following characteristics: \ x0d \ 1. It is a free software, and you can freely install and modify the source code of the software. \ x0d \ 2。 Linux operating system is compatible with mainstream UNIX systems, which makes it have a good user base as soon as it appears. \ x0d \ 3。 Support almost all hardware platforms, including Intel series, 680x0 series, Alpha series, MIPS series, etc. , and widely supports various peripheral devices. \x0d\ At present, Linux is rapidly spreading all over the world. Major software vendors such as Oracle, Sybase, Novell and IBM. Both have released Linux versions of their products, and many hardware manufacturers have also introduced server products with Linux operating system pre-installed. Of course, PC users can also use Linux. In addition, there are many companies or institutions that collect software about Linux in a planned way and combine it into a complete Linux distribution for listing. Famous companies are RedHat and Slackware. Although it is too early to say that Linux will replace Unix and windows, a software with excellent stability, flexibility and ease of use will certainly be used more and more widely. \x0d\ IV。 Unix system \x0d\ Unix system came out in 1969 and was originally used on small and medium-sized computers. The earliest Unix system transplanted to 80286 microcomputer is called Xenix. Xenix system is characterized by short and lean, low system overhead and fast running speed. After years of development, Xenix has become a very mature system. The latest versions of Xenix are SCO Unix and SCO CDT. At present, the main versions are Unix 3.2 V4.2 and ODT 3.0. \x0d\ Unix is a multi-user system, which generally requires more than 8M of memory and a large-capacity hard disk. Apple's Mac system is also based on Uninx system, and Unix system is by far the safest and most stable system! \ x0d \ There are several versions of UNIX system at present, such as IBM, HP, SUN, MAC, etc. Among them, MAC system has the largest shipment and still occupies a leading position in the field of industrial design. The GUI development of Windows system comes from MAC, including the pc system model we use now, and many designs are imitated by Apple. Version X Tiger10.4 of MAC OS began to support x86 architecture. According to Apple's official statement, the version of Mac OS X Tiger 10.5 will be released soon, and the battle for operating system will begin a new prelude. \x0d\ Kirin operating system developed by China is also based on Unix \x0d\ v and OS/2 system \ x0d \1987. In the fierce market competition, IBM introduced PS/2(Personal System/2) personal computer. PS/2 series computers have greatly broken through the current PC system, adopting the microchannel bus MCA which is incompatible with other buses, and IBM has designed about 80% of the components of the system to prevent other companies from copying. \x0d\ OS/2 system is a new multitasking operating system developed for PS/2 series computers. OS/2 overcomes the limitation of 640KB main memory in DOS system and has multi-task function. OS/2 also uses a graphical interface, which is a 32-bit system. It can not only handle the application software of 32-bit OS/2 system, but also run 16-bit DOS and windows software. \x0d\ OS/2 system usually needs 4MB of memory and 100MB hard disk or higher hardware environment. \x0d\ IBM announced last year that the OS/2 system will stop selling on June 5438+February 3, 2006/kloc-0, and its system platform will transition to Linux. After 20 years of ups and downs, os/2 system will die.