PC Networking: How It All Began

Computing and the advances that led to the modern personal computer go as far back as the human race itself, way back to devices such as the abacus (500 B.C.) and the Jacquard loom (a nineteenth-century mechanized loom that used a series of punch cards to create a particular weave ). While our focus in this book is the networking of the personal computer, a little background information on the evolution of modern computing makes sense. To start, we can jump ahead to the 1950s.

Mainframes and Miniframes

Although there were a number of super computers created prior to 1950, the early mainframe market (which was not all that huge because of the size and cost of these computers) was dominated by International Business Machines (IBM). The IBM Model 701, which used vacuum tubes, was created in 1952. IBM also led the field in mainframe innovations and introduced the first computer disk storage system, as well as developed the FORTRAN programming language.

Advances in technology lead to the development of a smaller version of the mainframe, the miniframe . In the 1970s, the miniframe gained dominance in the computing world, making computer technology accessible to a larger number of companies and organizations (even though these companies paid a premium for their ability to compute).

One point that should be made in relation to mainframes and miniframes is that, by design, all storage and computing power was centralized. This meant users (on dumb terminals) accessed centralized, shared information and used centralized applications provided by the miniframe. In many cases, some type of messaging system was also available to users on a mainframe or miniframe so that they could communicate.

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Vacuum tubes were used in early computers to convert alternating current to direct current, a function that is handled in computers today using circuit boards .

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When a company or organization plans a LAN or WAN implementation, the core purpose of creating the computing network should always be kept foremost in mind. LAN and WAN technology offers many possibilities for networking computers, with some of the possibilities sporting more " bells and whistles" than the alternative (meaning, there are a number of ways to network computers: Some are glitzy but expensive; some are boring, yet fiscally sound and technically effective). In a perfect world, LANs and WANs should be built using the appropriate technology to meet the networking needs of the company or organization.

The Advent of the PC

Many techno-historians would debate which of the personal computers that appeared in the late 1970s and early 1980s really captured the imagination of early PC computer users and led to the personal computer revolution.

In August 1981, the IBM PC was released. Although not the only heavy- hitting PC available in the 1980s (the Apple Macintosh was released in 1984), the IBM PC (see Figure 1.1) quickly became the standard for businesses. Because the operating system for the IBM PC, DOS, was not wholly owned by IBM (Microsoft made MS-DOS available to other PC manufacturers), clones of the IBM PC quickly appeared in the marketplace . This made the PC a tool that even individuals and the smallest of businesses could afford.

Figure 1.1. The IBM PC became the standard desktop computer for businesses.

The development of software applications for DOS-based machines exploded in the 1980s, cementing the PC's role as the business-computing workhorse. However, the fact that PCs were standalone devices meant that users could not readily collaborate and share resources. The PC basically isolated its user .

Connecting PCs

Given that IBM brought a standalone, decentralized computing devicethe PCto the business marketplace in 1981, one would think that the theory, hardware, and software used to network PCs together had yet to be developed. In fact, though, the issues related to networking PCs had been worked out prior to 1980 by the ingenious researchers at the Xerox Corporation's Palo Alto Research Center (PARC). Not only did they create the Alto, a computer with a graphical user interface (GUI) and a mouse, but they also developed the hardware and software necessary to connect computers and printers together into a LAN.

In 1976, PARC researchers Robert Metcalfe and David Boggs (Metcalfe's assistant) published a paper titled "Ethernet: Distributed Packet-Switching for Local Computer Networks." Ethernet (discussed in detail in Chapter 4, "Building the Network Infrastructure") was further developed by Xerox, Intel, and DEC and is still the most popular PC networking architecture in the world.

As the PC gained dominance in the computing world, other network architectures were developed (such as IBM's Token Ring, which is discussed in Chapter 4). Many new companies, such as 3Com and Cisco Systems, surfaced in the 1980s and 1990s and grew rapidly as the need for networking interface cards and other network connectivity devices expanded in parallel with the evolution and sales of the personal computer.

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Dumb terminals consist of a monitor that is directly connected to the mainframe or miniframe and a keyboard, which also has a direct connection to the centralized computer.

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Oddly enough, Xerox never capitalized on many of the discoveries made at PARC. Apple was actually the first company to introduce a computer with a GUI interface and a mouse when it unveiled the Macintosh in 1984.