Passage: Microsoft's Altair BASIC was popular with computer hobbyists, but Gates discovered that a pre-market copy had leaked into the community and was being widely copied and distributed. In February 1976, Gates wrote an Open Letter to Hobbyists in the MITS newsletter in which he asserted that more than 90 percent of the users of Microsoft Altair BASIC had not paid Microsoft for it and by doing so the Altair "hobby market" was in danger of eliminating the incentive for any professional developers to produce, distribute, and maintain high-quality software.  This letter was unpopular with many computer hobbyists, but Gates persisted in his belief that software developers should be able to demand payment. Microsoft became independent of MITS in late 1976, and it continued to develop programming language software for various systems. The company moved from Albuquerque to its new home in Bellevue, Washington, on January 1, 1979.During Microsoft's early years, all employees had broad responsibility for the company's business.  Gates oversaw the business details, but continued to write code as well. In the first five years, according to Bill Gates' own claims, he personally reviewed every line of code the company shipped, and often rewrote parts of it as he saw fit.

Question: When did Microsoft become seperate from MITS?
1976