I am a Southwest Technical Products 6800 collector and I normally define the first personal computers as those made before mid 1977. (You could be strict and say they had to introduced in 1975.) Almost all of these were only available in kit form. Even the Apple 1 and KIM required you to build a power supply. In mid 1977 the Apple II , the PET and the TRS 80 brought personal computers to those who did not know which end of a soldering iron you held. I don't know how many SWTPC 6800 were made, I still have 3. SWTPC never have a large market share but lasted longer than most of the early companies. They made computers until the mid 1980s. Michael Holley www.swtpc.com/mholley computers