A Simple Configuration

The basic, or least expensive, configuration for a personal computer is a monochrome monitor, a minimal amount of RAM, and one disk drive. RAM is measured in KB or MB; a simple configuration has 640K (655,536 bytes). Most PC-compatibles have either 1MB or 2MB of RAM as standard equipment. The Macintosh Classic II comes standard with 4MB.

A Full Configuration

While you may not need a fully loaded car, it is often sensible to have a fully configured personal computer. A full configuration for a state-of-the-art personal computer system includes a color monitor with high-quality screen display, at least 2MB (and up to 8MB) of RAM, two floppy disk drives (one for 5¼-inch and one for 3½-inch disks), and one hard disk with at least 30MB of storage capacity. A color display is useful if you plan to use graphics software. In addition, many non graphic programs, even word processing, are primarily intended for a color monitor, and can be awkward to use on a monochrome display.

Many applications have grown more complex and have added more features, requiring more RAM. For example, word processing programs often include a spelling or grammar checker. Complex spreadsheets, filled with numbers and calculations, require large amounts of memory too. Generally speaking the more RAM, the better. It is not uncommon to use applications that require most of the 640K of main memory. Likewise, hard disk drives become more useful when working with large programs that come on multiple disks. Without a hard disk, you have to swap the floppies in and out of the floppy disk drive when you need to perform different operations. A hard disk allows you to store the entire program, with no disk swapping. Programs often run more smoothly from a hard disk.

Types of Personal Computers

Desktop personal computers are commonly used for education, running a small business, or, in large corporations, to help knowledge workers be more productive. Some of the more common types of desktop personal computers are

• thе IBM PC and PC-compatible

• thе IBM PS/2^®.

• the Apple^® Macintosh^™.

While there are many other desktop personal computers, such as the Amiga, Apple II, Apricot, and Atari, their use is not as widespread. People tend to choose a personal computer based on the software they wish to use. Software developers, hoping to sell as many copies of their programs as possible, write applications for the personal computers they believe will be widely used for a long time — in other words, they try to bet on the winner. In this way, the software industry actually can make a new personal computer either a success or a failure.

Ibm pCs and pc-Compatibles

The IBM Personal Computer, or IBM PC, was the most widely used —and widely copied — personal computer. Originally, IBM considered its PC a home computer. However, corporate America was quick to recognize the PC's usefulness in boosting knowledge worker productivity. Up until this time, when knowledge workers needed to use a computer, it was usually a mainframe or a minicomputer. But sometimes it wasn't possible to accommodate everyone who needed to work on the computer. In addition, applications suited to an individual worker were limited.

The IBM PC was designed as an open architecture machine. Open architecture means the specifications are available to outside organizations so they may develop compatible software and hardware products. The open architecture philosophy also made it possible for other computer companies to design personal computers that worked almost identically to the IBM PC. Thus, the PC-compatible market was launched, and eventually eclipsed IBM's sales of its own PCs. Companies such as Compaq, Tandy/Radio Shack, Zenith, Epson, and NEC built PC-compatibles with the same types of microprocessor. They used the MS-DOS^® operating system, developed by Microsoft Corporation, which was nearly identical to IBM's PC-DOS. This made it possible to use almost any software for the IBM PC on a PC-compatible.

These companies followed in IBM's footsteps, introducing an XT-compatible and then an AT-compatible shortly after IBM's machines debuted. But in 1986, Compaq decided to take a chance and beat IBM to market with a personal computer that used the newest and fastest microprocessor, the Intel 80386. It was called the Deskpro 386/20 and was followed shortly by the Portable 386. Compaq went on to set the record for reaching the Fortune 500 faster than any other company in history.

Today, the 386 microprocessor is the standard for most personal computers in the office. However, many personal computers already use its successor 80486, and Intel plans to introduce the 80586 in 1993; the 80686 will follow sometime thereafter. These microprocessors bring even greater speed and efficiency and represent the promise of the desktop supercomputer.