The creation of the IBM Personal Computer in the early 1980s was a landmark event that reshaped the technology landscape. A critical, and perhaps surprising, aspect of this endeavor was IBM's decision to outsource key components, including the operating system. This strategic choice led to a foundational partnership with a then-young company, Microsoft, to develop what would become IBM PC DOS. This collaboration, particularly evident during the development
of the PC DOS 3.x series, illustrates a unique dynamic between two tech giants that profoundly influenced the trajectory of personal computing.
IBM's Strategic Outsourcing Decision
IBM's task force, assembled to develop the PC, made a radical departure from the company's traditional internal development model. They decided that crucial components, including the operating system, would be sourced from external suppliers. This decision was instrumental in making the IBM PC an industry standard. Among the potential partners, the private company Microsoft, founded by Bill Gates five years prior, was ultimately chosen to write the operating system. This choice was not without its specific motivations from IBM's side.
According to task force member Jack Sams, IBM wanted Microsoft to retain ownership of any software they developed. This was a deliberate move to avoid potential lawsuits, as IBM had faced significant legal challenges in the past from individuals claiming the company had stolen their tools or code. By ensuring Microsoft owned the software, IBM aimed to mitigate such risks. This meant IBM did not want to directly assist Microsoft beyond providing a remote proposal, emphasizing a clear separation of development responsibilities and ownership from the outset of their collaboration.
Forging the Agreement and Early Market Dominance
The initial contact between IBM and Microsoft to explore this partnership occurred in July 1980. Negotiations progressed swiftly over the following months, culminating in the formal signing of a contract in early November of the same year. This rapid agreement set the stage for the development of PC DOS, which would become the primary operating system for the new IBM PC. Despite the availability of other operating systems, such as CP/M-86 (which became available six months after PC DOS) and UCSD's p-System, IBM anticipated that most customers would opt for PC DOS.
IBM's expectation proved accurate, as evidenced by a survey that revealed a significant market preference. The survey indicated that 96.3% of PCs were ordered with PC DOS, which was priced at a modest $40. In stark contrast, only 3.4% of orders included CP/M-86, which carried a much higher price tag of $240. This overwhelming adoption of PC DOS cemented its position as the de facto standard for IBM personal computers, largely due to the strategic partnership that brought it into existence.
Evolving Collaboration and Joint Development
As the IBM PC DOS platform matured, particularly around the time of the 3.x series, the nature of the IBM-Microsoft partnership continued to evolve. By the completion of PC DOS 3.0, IBM had cultivated its own dedicated team of developers responsible for the entire operating system. This internal capability allowed IBM to contribute significantly to the ongoing development. By 1985, a formal Joint Development Agreement (JDA) was established between the two companies for PC DOS development.
Under this JDA, each company was responsible for creating a fully developed version of the operating system and providing it to the other. While most branded versions of DOS were largely identical, there were specific instances where each company introduced minor modifications to their respective versions. This arrangement highlighted a complex relationship where both entities collaborated closely while also maintaining a degree of independent development. For example, in the fall of 1984, IBM provided Microsoft with all the source code and documentation for IBM TopView for DOS, an internally developed operating environment. This transfer of knowledge was intended to help Microsoft gain a deeper understanding of object-oriented operating environments, how to implement overlapping Windows (for the development of Windows 2.0), and multitasking techniques (Windows initially used cooperative multitasking for CPU sharing throughout the Windows 1.0 to ME lifecycle). This exchange underscores the depth of their collaboration and its far-reaching impact on the future of personal computing software.
