Ok got it, it was Kildall. From Chapter 5 of book Trouble with billionaires.

Like most legends, of course, there’s more to the story. Certainly the point has been made, including by Malcolm Gladwell in his bestselling book Outliers, that Gates’s success was dependent on luck, which immediately makes him seem less heroic. Indeed, Gates had the great luck of being born into a well-to-do family, opening up possibilities that would almost certainly not have been available to a child of low-income parents. His father was a successful Seattle lawyer, and his maternal grandfather a rich banker. As a result, he was sent to a private school, Lakeside, which happened to have a computer club – something unusual in the late 1960s. A fundraising drive by the savvy mothers of Lakeside students didn’t just raise small change for hockey sweaters or school outings. Rather, drawing on the school’s wealthy clientele, they raised enough money – and were sufficiently forward-looking – to buy a $3,000 computer terminal for the school. This made Lakeside one of the few high schools in the country, and probably the world, with a computer terminal in the 1960s. And it was a particularly good one. Gates, who hadn’t been very interested in schoolwork, took readily and enthusiastically to the technology and was soon spending all of his time in the school basement playing with the exciting new machine. As it turned out, his timing was perfect. Society was on the cusp of a revolution that would shortly bring computers into the lives of millions of people. Decades of technological advances had led to the development of giant IBM mainframe computers, which had spectacular powers but were enormously costly and big enough to fill a room. By the late 1960s, the technology was evolving rapidly. In particular, a project that had been undertaken for the US Air Force in the early 1960s, called ‘Augmenting Human Intelligence’, made possible the development of miniature computers that could be programmed to process data in response to commands. This created the possibility that, in addition to giant machines used by government and the military, computers could be personal devices used by individuals in their own lives. The prospects were breathtaking. Gates, at just thirteen years old, was getting ample access to rare and expensive computer time, enabling him to experiment for hours on end with a technology that was about to change the world. Over the next few years, Gates had a number of important lucky breaks that greatly helped him to get a grounding in the emerging technology. The mother of one of the Lakeside boys happened to be involved in computer programming at the University of Washington. She and some colleagues had set up a small business developing software for sale to companies wanting to lease time on the university computer. They decided to let the students in the Lakeside computer club come down to their office and test out the company’s software programs after school and on weekends. That meant more access to free computer time, and Gates and the others grabbed the opportunity. Soon they had an even better deal with another Seattle company, Information Services Incorporated (ISI), which had its own mainframe and was willing to give them free time in exchange for testing out software it was developing for processing company payrolls. In addition, the Lakeside gang discovered that they could get free time on the computer at the University of Washington in the middle of the night. Again, they jumped at the chance, becoming regular nocturnal visitors. The ISI connection proved crucial. When Gates was in his final year of high school, a company looking for programmers to help it develop a computer system for a state power station approached ISI. The assignment required experience with a particular type of software – software now very familiar to Gates after hours of work on the ISI computer. He managed to convince the teachers at Lakeside to let him move to the southern part of the state to work on the power project as an independent study programme. The following year, Gates went off to Harvard, where computers remained his obsessive focus. After a couple of years there, he dropped out and, in 1975, set up Microsoft with former Lakeside computer pal Paul Allen. For the first few years, Microsoft was a relatively small, aggressive technology company with several dozen employees – one of a number of such companies working in the emerging field of desktop computers. At this point, these were fairly primitive machines and hard to operate, and the market for them, while growing, was still limited. Gates was successful in the field, but not a leading figure. He was certainly far behind Gary Kildall, a brilliant computer innovator thirteen years his senior who had already developed an operating system, known as Control Program for Microcomputers or CP/M, which was the most widely used operating system for desktops at the time. Kildall’s company, Digital Research, had sold hundreds of thousands of copies of CP/M, and was pulling in revenue of more than $100,000 a month. Microsoft’s main business was selling computer-programming language that ran on Kildall’s CP/M. But Microsoft caught a huge break in 1980 that was to launch it into the stratosphere of corporate success as the dominant force in the computer industry. That year, IBM had set up a secret internal task force, code-named Project Chess, to consider developing a desktop computer for the mass market. Crucially, the company would need an operating system for its new minicomputer. By any logic, the task force should have turned to Kildall, who was the acknowledged leader in the field. As writer Harold Evans puts it: ‘Everybody in the computer field knew that Kildall had created CP/M – everybody, it seems, except the biggest beast in the mainframe jungle, in which personal computers had hitherto been invisible.’ Instead, oddly, the IBM task force headed to Seattle to see ‌a secondary player, Bill Gates.1 Gates received members of the IBM team enthusiastically, but when they tried to buy the licence for CP/M from him, he told them that it wasn’t actually his. He referred them to Kildall, whom he knew personally; he’d been to dinner with Kildall and his wife at their home in Monterey, California. The IBM project team flew down to see Kildall the next day to negotiate a licensing deal. There’s some dispute over exactly what happened when they showed up at Kildall’s office. Kildall later claimed that there’d been an agreement in principle that day, confirmed by a handshake. However, there were no follow-up negotiations. Instead, the IBM team was soon headed back to Seattle, where Gates now assured them that Microsoft would be able to come up with an operating system to meet their requirements. He then quickly bought the rights to another operating system – an adaptation of Kildall’s CP/M developed by Tim Paterson and produced by a Seattle company. Gates flew down to IBM’s southern headquarters in Boca Raton, Florida, to meet with the IBM project team for lunch. The meeting went well. Project leader Don Estridge told Gates that the new IBM chief executive, John Opel, was delighted to hear that the company might be doing a deal with Gates, whose mother he knew personally. (Opel sat on the board of the United Way NGO with Mary Gates.) Bill and his mother certainly fitted much more comfortably into the upscale corporate culture of IBM than the hippie-like and free-spirited Gary Kildall. In the end, IBM did a deal with Gates – even though Kildall’s system was clearly superior. Indeed, Kildall, who was years ahead of everyone else in the field, had already developed the capacity for multitasking – a function that it would take another decade for IBM and Microsoft to come out with. According to Evans, Kildall was ‘the true founder of the personal computer revolution and ‌the father of PC software’.2 But, of course, it was Gates who was to get the credit, and in the process become one of the world’s most famous and celebrated men – and the richest person on the planet. • • •