Brief introduction to the operating system
http://www.snut.edu.cn/wlkt/learn/software/01_windows/
1. Simple history of operating system development
The operating system is a platform to manage computer software and hardware resources, without it, any computer is not working properly. In the history of personal computer development, there have been many different operating systems, which is most commonly used: DOS, Windows, Linux, UNIX / Xenix, OS / 2, and the following introduces the development process and function of these five microcomputer operating systems, respectively. Features.
The hardware platform is BIOS, which is an operating system, and then the customer's application.
1. DOS platform
Since 1981, DOS has experienced 7 large version upgrades, from now on version 7.0, continuous improvement and improvement. However, the single-user, single task, character interface, and 16-bit larger profiles of the DOS system have not changed, so it is also limited to 640KB management management management. DOS was originally developed for IBM-PC, so it was very low for hardware platforms, even for DOS6.0's high version DOS, at 640KB memory, 40MB hard drive, 80286 processor's environment can also be operated. Therefore, the DOS system is suitable for use in high-grade microcomputer and is suitable for low-grade microcomputer.
Common DOS has three different brands, which are Microsoft's MS-DOS, IBM's PC-DOS, and Novell's DR DOS, which is compatible, but there are still some differences, three DOSs Using the most MS-DOS.
2. WINDOWS operating system
Windows is the first generation window multitasking system issued by Microsoft in November 1985, which enables the PC to enter the so-called graphical user interface (GUI: Graphic User Interface "era.
The Windows1.x version is a version with multi-window and multi-tasking features, but because the hardware platform at the time is PC / XT, the speed is very slow, so the Windows1.x version is not very popular. At the end of 1987, Microsoft launched the MS-Windows2.x version, which has a window overlapping function, and the window size can also be adjusted, and the extended memory and expansion memory as disk cache, which improves the performance of the entire computer, in addition to it It also provides numerous applications: Text Editing Write, Notepad Notepad, Calculator, Calendar Calendar ... etc. Subsequently, in 88, two versions of MS-Windows / 286-V2.1 and MS-Windows / 386 V2.1 and MS-Windows / 386 V2.1 were launched.
In 1990, Microsoft launched Windows 3.0, its features further strengthened, with powerful memory management, and provided quite a number of Windows applications, so it became 386,486 microcomputer new operating system standards. Subsequently, Windows released version 3.1 and launched the corresponding Chinese version. The version 3.1 increased from version 3.0 added some new features, which was welcomed by users, which was the most popular Windows version.
In 1995, Microsoft launched Windows95 (also known as Chicago or Windows 4.0). The previous Windows is guided by DOS, that is, they are not a completely independent system, and Windows95 is a completely independent system, and further improvements in many ways, but also integrate network functions and Plug and play function is a new 32-bit operating system.
In 1998, Microsoft launched Windows95's improved version of Windows98. The biggest feature of Windows 98 is to integrate Microsoft's Internet browser technology into Windows95, making access to Internet resources as convenient as accessing local hard drives, thus better meeting people. More and more access to Internet resources. Of course there are quite a lot, but this article writes too early, so there is no involvement, wait a solution. . . . 3. Linux system
Linux was originally developed by Finnish Linus Torvalds. The source program is publicly released on the Internet, thereby triggeting the enthusiasm of global computer enthusiasts. Many people download the source program and perfect the functionality of a certain aspect, and then Send it back online, Linux is also carved into a world most stable, most developed operating system. Once people play: If Bill Gates puts the Windows source code, many bugs remain in Windows have long been there, because the world's computer enthusiasts will become Windows's obligations and programmers. .
The Linux operating system has the following characteristics:
1. It is a free software, you can freely install and arbitrarily modify the source code of the software.
2. Linux operating system is compatible with mainstream UNIX systems, which makes it a good user group.
3. Support for almost all hardware platforms, including Intel Series, 680x0 Series, Alpha Series, MIPS Series, etc., and widely support a variety of peripheral equipment.
4. UNIX system
The UNIX system was advent from 1969, which was originally used on small and medium-sized computers. The first to transplant the UNIX system on the 80286 microcomputer called Xenix. The Xenix system features a short, small system overhead, fast running. After years of development, Xenix has become a very mature system, the latest version of Xenix is SCO UNIX and SCO CDT. The current main version is UNIX 3.2 V4.2 and ODT 3.0.
Unix is a multi-user system that generally requires more than 8M memory and larger-capacity hard drives.
5. OS / 2
In 1987 IBM introduced PS / 2 (Personal System / 2) PC in fierce market competition. The PS / 2 series computer has greatly broken through the current PC system, using a microchannel bus MCA that is incompatible with other bus, and IBM designs about 80% of the system to prevent other companies.
The OS / 2 system is a new multitasking operating system developed for the PS / 2 series machine. OS / 2 overcomes the limitations of the 640KB main memory of the DOS system, with multiple task features. OS / 2 also uses a graphical interface, it itself is a 32-bit system, not only 32-bit OS / 2 system applications, but also 16-bit DOS and Windows software.
OS / 2 systems typically require running in 4MB memory and 100MB hard drives or higher hardware environments.
two. Some related knowledge (there will be some chaos)
One of Windows XP's goals is to provide 32-bit and 64-bit versions for customers. The development of Windows XP 64-bit is synchronized with Intel's 64-bit processor (code itanium) and is expected to be sold in synchronization with the processor. Windows XP is an important step in implementing Microsoft .NET ideas, while Windows XP-based PCs will be the center of the .NET experience, which allows users to transfine people's restrictions, implement a redefine person , The complete calculation experience of the relationship between the software and the Internet. The original Windows 3.x system is just a 16-bit application of DOS, but the clipboard, file drag, etc. appear in Windows 3.1, which makes the user's operation simple in Windows 3.1. When 32-bit Windows 95 is released, some of Windows3.x is retained. Windows 98 is the last version of Windows 9x, which has two versions of Windows 95 and Windows 95 OEMs before it. Windows 95 OEM is often said to Windows 97. In fact, these three versions have no big difference, they are Previous version of improved products. The more the types of hardware devices that can be supported, the more technologies adopted are increasingly advanced. Windows Me (Windows Millennium) features Windows 9X and Windows 2000 feature, which is actually improved by Windows 98, but in terms of interface and certain technologies are imitating Windows 2000. Microsoft claims that DOS is removed in Windows ME, no longer based on DOS. But in fact, not this, DOS still exists, but cannot be entered through normal steps, and there is an article "Restoring Windows Mode" in various media. Windows 2000 is Windows NT 5.0, which is a version that Microsoft is launching to solve the instability of the Windows 9x system and multimedia support for Windows NT. It is divided into two versions of Windows 2000 Perfessional and Windows 2000 Sever. The former is a normal user, and the latter is a network server. The rear of the hardware requirements are higher than the former.
64-bit enterprise applications must be built on a 64-bit database platform, so only 64-bit operating systems are not enough. With a 64-bit operating system, there is 64 SQL Server, plus 64-bit enterprise-level applications Visual Studio.Net 2003, which constitutes a complete enterprise-level application development and operational environment, and the three are unable.
Since the ".NET" application is first embedded - .NET Framework, the Windows Server 2003 is a platform for ".NET" application. In addition, Visual Stidu.net 2003, which released at the same time, not only for 64-bit platforms, but also further facilitated the development of ISV ".NET" applications.
Windows Server 2003 also has a payment of concern that using plugin technology to maintain the operating system for new technologies and new applications. Usually, the new features can only be added by patch or new versions, while the patch is subject to the task of repairing the repair, and the addition of new features is extremely limited, and the number of updated versions is also Limited, as after Windows 98, Microsoft launched Windows 98 SE (second edition). Therefore, these two ways to support the support of new technologies or is either not in time. Microsoft borrows the concept of bus in the hardware system in Windows Server 2003, making new technologies and new applications into plugins, ready to insert into the operating system. Microsoft promises that dozens of plug-ins will be released for free download, making Windows Server 2003 a "dynamic update" operating system, but also guaranteed the user's return on investment. The Franchisement of Windows Server 2003 makes the Windows family a complete operating system family, such as mobile devices such as mobile devices such as mobile phones, PDAs, etc., to client devices such as mobile devices such as mobile phones, PDAs, until the highest-end data center server. Users can use multiple programming languages, write .NET applications, can run on different platforms of the Windows family.
