A Short History of PCs

It probably surprises few people when we say that computing has changed dramatically since the invention of the Personal Computer. Not only has the PC revolution turned the industry on its collective ear, we continue to see both software and hardware advances. In the 1950's when the mainframe was king, IBM decreed that a handful of mainframes would provide all the computing power that the entire United States would need. The statement was much like that of earlier prognosticators who declared that we could never go faster that forty miles an hour, man was never meant to fly, or that everything had been discovered by the end of the nineteenth century. From the time that a handful of mainframes was thought to be sufficient, to the millions of personal computers in use today, every aspect of life has been affected by the computer. Although other microchips were in development at the time, Intel's first patented microchip proved to be the beginning of what is now a huge industry. The microchip is now everywhere from the home computer to the automobile.

One of the key events in the fostering of this industry was the development of software that would run on the new Personal Computers and allow individuals to produce their own programs. In the early eighties there was still some doubt as to what software that might be. There were two major contenders, Gary Kildall's CPM operating system and Bill Gates' DOS. The story is probably part legend and part fact but has become a retold tale much like George Washington and the cherry tree. Supposedly IBM approached both Kildall and Gates for proposals for a new operating system for IBM's new personal computer. History has it that Kildall was out flying and failed to return the IBM call while Gates was prompt to see an opportunity and immediately cut a deal to license both DOS and a version of the BASIC programming language to IBM. The result was a significant amount of royalties for the fledgling Microsoft and the basis of Microsoft's dominance in the desktop market.

The early versions of the desktop computer were built on microchips from two companies, Intel and Motorola. For the home user the difference was Apple Vs the IBM standard. Although Apple was the first and most innovative, the IBM/DOS combination proved to be the more attractive for business. The principal reason for this was Intel's careful plan to insure that each new generation of chip would run software developed for the previous chip. This is known as backward compatibility. Motorola was less concerned with backward compatibility and chose to develop chips that were better but could not necessarily run old programs, a problem seen in different models of the Apple. Because technology changes rapidly, businesses trying to stay competitive did not want to replace software with every new purchase of hardware. They stayed with the Intel platform mainly to protect their investment in software. The end result was an overwhelming dominance of Intel in the marketplace.

Microsoft was also careful to cover both Intel and Motorola, becoming the largest supplier of software for both platforms. It was also careful to insure that each generation of its software would be backward compatible with the previous generations. They have been mostly but not completely successful with this attempt. Those who read computer magazines, however, will be aware that the evolution of Microsoft's operating systems and languages were not without problems. Some of which were caused by the necessity to maintain this backward compatibility. As the DOS platform evolved things would show up in new versions of DOS like the SETVER.EXE program. Since the underlying design of the microchip was changing and DOS, as a software program, needed to be backward compatible SETVER was used to check for programs that would not recognize new versions of DOS then ‘fool' the program into thinking it was running under an old version of DOS.

Microsoft has continued their software changes first with new versions of DOS then Windows under DOS, Windows for Workgroups, Win95 and Windows NT. Each stage of development has paralleled the advances in microchip design. DOS was originally a text based operating system. The first versions of Windows worked with DOS as an underlying program and added a GUI (Graphical User Interface, pronounced gooey) front -end. DOS and Windows spanned the 8 bit Intel chip and the 16 bit chip. When the new 32 bit chips were introduced Microsoft added two new operating systems, Win95 and Windows NT. Win95 sported changes to the look and feel of its GUI and attempted to maintain backward compatibility with older 16 bit DOS programs and newer programs developed for the 32 bit environment. Windows NT is a completely re-written operating system designed for the new 32 bit chips. Of the two current versions Win95 is positioned as the desktop environment and Windows NT as the high end environment for computing intensive programs like CAD (computer aided drafting). Software development for DOS is nearly defunct while development for the newer 32 bit systems is in full stride.

Of the three systems available now, Windows, Windows 95, and Windows NT, the most popular is proving to be Win95 with something on the order of 50 million copies sold in the last year.