Workstations And Servers

There are two basic types of computers you will encounter when working with Windows NT: workstations and servers. A workstation computer is either a standalone computer or a network client. It is rarely both, unless it is a portable computer that is sometimes connected to a network. A server, on the other hand, is a computer that shares its resources for use by network clients. In the following sections, we will explore some of the various types of workstations and servers. Let’s begin with a look at the various types of workstations you may encounter.

Workstations

For the most part, a workstation is any computer used to perform a task locally. By this, I mean the workstation computer is used by an individual to perform a specific action. This might be writing a letter with Word for Windows, for example. Or it might be developing an application using a compiler. It is not the operating system that defines a workstation computer, but rather the work performed on the system. The key word that defines a workstation is interactive. All workstations are used interactively by their operators. You may encounter various types of workstations that use different operating systems, including:

•  MS-DOS—The Microsoft Disk Operating System, or MS-DOS, is not as widely used as it once was, but it is still out there lurking. The main reason it is still used is because not everyone has migrated to Windows 95 or Windows NT. Sometimes, this is because the client computer is an 8086 or 80286 (yes, there really are people still using XTs and ATs) or a proprietary application required for a company’s well-being can only function under MS-DOS. An MS-DOS computer usually has only a megabyte or two of RAM available, which is insufficient to run other operating systems.

•  Windows 3.x—Microsoft Windows 3.x also requires MS-DOS to function, and you could include a Windows 3.x computer in the same realm as MS-DOS except for the fact that Windows extends the computer’s capabilities. These Windows 3.x workstations are usually 80386 or 80486 computers. The primary reason they are still in use is because these computers lack the processing capacity to run Windows 95 or Windows NT well, or because the cost to upgrade to Windows 95 is too much for the company budget to bear. These computers may also function quite well in limited amounts of system RAM (2MB to 4MB) and disk storage. They may also perform their current tasks well enough, so there just may not be any reason to upgrade.

•  Windows for Workgroups—Like Windows 3.x, these computers are also usually 80386 or 80486 computers with 4MB to 8MB of system RAM and limited disk storage. They also follow the same reasons for not upgrading to Windows 95 or Windows NT. They offer two major benefits over previous versions of Windows. A Windows for Workgroups workstation can run some 32-bit (WIN32s) applications, and they can share resources in a peer-to-peer workgroup model.

•  Windows 95—Windows 95 workstations are currently used to replace previous versions of Windows and MS-DOS, and they operate quite well in a Windows NT-based network. These computers to not utilize the trust concept (unique to Windows NT) but operate quite well as network clients. Windows 95 was built with networking in mind and is a better network client than previous versions of Windows. However, it requires more resources than previous versions of Windows. For good performance, a Windows 95 computer requires a Pentium class processor, 8MB to 16MB of system RAM, and a 1GB hard disk. While you can use a smaller hard disk, Windows 95 applications are quite large, and full installs of these applications will quickly consume a 500MB or smaller hard disk.

•  Windows NT Workstation—Windows NT Workstation is the cream of the crop when it comes to workstations. It requires almost the same resources as Windows 95, but it is much more stable. The major hardware requirement difference is that Windows NT Workstation requires at least 16MB of system RAM. There are really only three reasons why you might not want to use Windows NT Workstation in favor of Windows 95:

•  Windows NT costs about twice as much as Windows 95.

•  Windows NT Workstation is not as compatible with legacy applications as is Windows 95. This means that Windows NT Workstation might not run all of your older MS-DOS and Windows 3.x applications, nor will it run most of your Windows 95 games, even those that use the Direct Play APIs.b Most games manufacturers utilize undocumented Windows 95 APIs to tweak their games for maximum performance. I have had limited success, however, with games from ID Software (Doom, for example) and a few Microsoft games.

•  Windows NT Workstation uses a different driver model than Windows 95, which means Windows NT Workstation does not support all of the hardware that Windows 95 does.

•  Macintosh—Macintosh workstations are usually limited to desktop publishing and graphics design implementations. A Macintosh workstation will fully interoperate in a Windows NT Server environment.

•  Unix—Unix workstations can also be utilized within a Windows NT Server environment but only in a limited fashion with the base software. To fully integrate Unix workstations, you need to purchase additional software. Intergraph provides some of the best Unix integration software on the market today, and, should you have Unix workstations, I highly recommend that you check out its software at www.intergraph.com.

While I really hate to muddy the water, I do have to mention that many workstations also provide the ability to share resources. While you might consider them a server, they really are not. These workstations use the peer-to-peer networking model. There is no hierarchy to the network. Instead, all computers are equal partners. All authentication to access resources is performed on the local computer. This differs quite a bit from a true server that utilizes a centralized user database for authentication, as does Windows NT Server. But there is more to a server than its centralized database, which is why the next section discusses the ramifications and resource requirements of various servers.