» The IBM PC, Part 3 The Digital Antiquarian

The Digital Antiquarian A history of computer entertainment and digital culture by Jimmy Maher Home About Me Table of Contents Ebooks Hall of Fame Table of Contents RSS ← The IBM PC, Part 2 The IBM PC, Part 4 → The IBM PC, Part 3 16 May In November of 1979, Microsoft’s frequent partner Seattle Computer Products released a standalone Intel 8086 motherboard for hardcore hobbyists and computer manufacturers looking to experiment with this new and very powerful CPU. The 8086 was closely related to the 8088 that IBM chose for the PC; the latter was a cost-reduced version of the former, an 8-bit/16-bit hybrid chip rather than a pure 16-bit like the 8086. IBM opted for the less powerful 8088 partly to control costs, but also to allow the use of certain hardware that required the 8-bit external data bus found on the 8088. But perhaps the biggest consideration stemmed, as happens so often, from the marketing department rather than engineering. The 8086 was such a powerful chip that an IBM PC so equipped might convince some customers to choose it in lieu of IBM’s own larger systems; IBM wanted to take business from other PC manufacturers, not from their own other divisions. The important thing to understand for our purposes, though, is that both chips shared the instruction set, and thus could run the same software. Everyone wanted to run CP/M on the SCP boards, but CP/M existed only for the Intel 8080 and Zilog Z80. Thus, SCP had the same problem that Sams and IBM would face months later. Digital Research repeatedly promised an 8086/8088 version of CP/M, but failed to deliver. So, in April of 1980 Tim Paterson of SCP decided to write his own 8086/8088 operating system. He called it QDOS — the “Quick and Dirty Operating System.” The ethicality or lack thereof of what Paterson did has been debated for years. Gary Kildall stridently claimed many times that he ripped off the actual CP/M source code, but this is a very problematic assertion. There is no evidence that he even had access to the source, which Digital, like most companies then and now, guarded carefully. On the other hand, Paterson freely admits that he pulled out his CP/M reference manual and duplicated each of its API calls one by one. On the other other hand, and while it may not have reflected much originality or creative thinking, what he did was pretty clearly legal even by the standards of today. Courts have ruled again and again that APIs cannot be copyrighted, only specific implementations thereof, and that reverse engineering is therefore allowed. (Well, there is patent law, but that’s a swamp we’re going to stay well away from…) Food for thought for open-source advocates and Microsoft haters: if QDOS was ethically wrong, then Linux — largely a reimplementation of the Unix standards — must be equally wrong. Paterson claims that he had a good reason to copy CP/M so closely: he wanted to make it as easy as possible for programmers to move existing CP/M software over to QDOS. He also claims that beneath the surface, where he could get away with it, he substantially improved upon his model, notably in disk- and file-handling. In the meantime Gates was wondering how he was going to come up with an operating system for IBM in the time frame they wanted. Then one day Paterson called Paul Allen of Microsoft to tell him about QDOS, just in case Microsoft was interested in writing some software for it or using it in-house. Gates, just the man to recognize an out-of-the-blue savior when he saw one, called Sams, asking, “Do you want to get [it], or do you want me to?” Sams’s answer to that question would cost IBM billions and billions over the decades to come. “By all means, you get it,” he said. Recognizing that PC software was far from his realm of expertise, Sams had already pretty much thrown all of his systems-software problems into Microsoft’s lap, and he saw no reason to change course now. “We wanted this to be their problem,” he later said. Microsoft’s “problem” would in a few years become a big, big problem for IBM. On September 30, Gates, Ballmer, and Bob O’Rear flew down to Florida to make their final proposal to IBM. For Sams, who wanted to essentially foist the software problem on someone else, their plan sounded ideal. Microsoft would take responsibility for providing an operating system, four programming languages (BASIC, COBOL, FORTRAN, Pascal), and a range of other software to be available at launch (including our old friend Microsoft Adventure ). One point Gates carefully stipulated: Microsoft would license all of this to IBM, not outright sell it to them, and would expect to be paid on a per-copy royalty basis. IBM, feeling there was opportunity enough for everyone to do well out of this and that it couldn’t hurt to have Microsoft’s own fate tied so closely to that of the IBM PC, agreed. This huge company, legendarily risk-averse and conservative, elected to place the fate of one of their b...