April 20, 2024
The Operating System and the Development of the PC
The History of PC Operating Systems
In 1980, IBM began development of a microcomputer. The decision was taken to purchase the operating system from outside the company. IBM contacted Bill Gates in the mistaken belief that Microsoft was the supplier of CP/M, regarded then as the de facto standard operating system for microcomputers. Microsoft was in reality a BASIC language vendor and the largest supplier of CP/M software.
Gates redirected IBM to Gary Kildall at Digital Research. Kildall had copied CP/M's command set from Digital Equipment's TOPS-10, a minicomputer operating system, and by inventing the BIOS, Kildall was able to easily port CP/M to other Intel-based systems. What happened next is disputed, but IBM, failing to deal with Kildall, returned to Gates who quickly agreed to supply an operating system for the IBM-PC.
However, Microsoft did not possess an operating system of its own, but swiftly purchased QDOS ("quick and dirty operating system") from Seattle Computer Products for $50,000. Kildall claimed that this was a copy of his own 16-bit version of CP/M. Whatever the truth of this allegation, Gates was now in possession of the newly christened MS-DOS and this would run on the IBM-PC under the name of PC-DOS.
The success of the IBM-PC in 1981 established Microsoft's position as the supplier of the de facto standard operating system. Gates, significantly, retained the rights to sell MS-DOS to other manufacturers and simultaneously offered IBM's rivals a number of applications to run with it. Many of these manufacturers sought 100% compatibility with the IBM-PC and Compaq's successful cloning operation in 1982 opened the floodgates for others to achieve this. MS-DOS, single user and single tasking, with its command line interface and 640K memory address limit, completed the picture.
It was apparent to many that other approaches would be necessary to take advantage of the latest, more powerful, microprocessors. The release in 1984 of the Apple Macintosh heralded the rise of the GUI breed of operating system. The Macintosh was derived from research made at Xerox PARC in the previous decade and reflected Steve Jobs' desire to produce a computer that was easy to use. Mac OS, with its more intuitive interface employing a desktop metaphor and mouse was radically different to the command line MS-DOS.
Bill Gates had also visited PARC and consequently Microsoft worked to overlay MS-DOS with a GUI. Windows 1.0, released in late 1985, was a 16-bit operating system that supported multi-tasking and required 1Mb of memory. Gates attempted to interest IBM in Windows but the latter wanted to develop its proprietary system OS/2. In 1989 a compromise was reached. Microsoft would develop Windows for low end users and OS/2 for IBM's more powerful machines. Software developers were now faced with deciding which platform to support, Windows, OS/2 or DOS.
The relationship with IBM deteriorated and Gates pushed the development of Windows. Microsoft already had immense leverage as the supplier of operating systems to most PCs on the market. Although less powerful, Windows did not have OS/2's drawback of requiring more memory. Gates, understanding that users were reluctant to change operating systems, made sure that Windows was compatible with DOS software. Microsoft took full advantage of its existing sales network to promote Windows as the successor to MS-DOS. With IBM's rivals supplying their machines preinstalled with successive versions of Windows, Microsoft had already sold several million copies before the release of OS/2 in 1992.
In 1995 Microsoft released Windows 95, its 32-bit successor to Windows 3x. With the subsequent release of Windows 98, Microsoft's position appeared to be impregnable. The company was estimated to have quarterly profits in excess of $2 billion with it various operating systems appearing on 90% of the world's desktop computers. However, Microsoft was beginning to take notice of a competitor.
In 1991 in Helsinki, a student named Linus Torvalds wrote an operating system for a PC based on a version of UNIX. He posted it to a software newsgroup for discussion. Linux attracted the attention of programmers who added improvements and new features such as a GUI and network capability. With thousands of programmers making contributions, Linux acquired a reputation for stability and versatility. By 1998 the operating system, with 7.5 million users, had attracted the concerns of Microsoft. A series of papers from Microsoft, dubbed the Halloween Documents, were leaked to the press and detailed a strategy for combating what was perceived as a serious threat to company's dominant market position.
The growth of Linux owes its success to the open source movement and can be traced back to the development of UNIX, for which the source code was made publicly available in the early seventies. The antithesis of Microsoft, open source espouses sharing knowledge as a means of benefiting mankind. Bill Gates has used operating systems to achieve huge profits and the source code for Windows is not in the public domain. The recent release of Windows 2000 sees hardware manufacturers and software developers expecting to make large profits on the strength of Microsoft's ability to generate a huge demand for new products.
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