[A full list of MS@45 content, resources and the schedule for our online experiences on the weekend of April 4-5 can be found here. Join in the celebration with us! #MSFT45]

This week at Living Computers Museum + Labs we are marking the 45th anniversary of the founding of Microsoft! As you may or may not know, Living Computers was founded by Paul Allen, the cofounder, along with his childhood friend, Bill Gates, of Microsoft. In this series we will explore the history of this enormously influential and successful company by looking at several key artifacts from our Living Computers collection that have played an outsized role in Microsoft’s history.

The genesis of what would later be Microsoft begins with this old-fashioned-looking machine pictured above. In the fall of 1968, 15-year-old Paul Allen first encountered “a gangly freckle-faced eighth-grader” named William Henry Gates III. The site of this historic meeting was the “Computer Room” at the private high school they both attended, Lakeside High School. Despite being “the most prestigious private school in Seattle,” Lakeside unfortunately could not afford an actual computer for their computer room! In 1968, computers cost tens of thousands of dollars at the very least. However, thanks to a rummage sale by the Lakeside Mothers Club, Lakeside was able to purchase one of these machines, a Teletype Model 33 ASR.

Half typewriter, half telegraph machine, Teletypes were state-of-the-art computer terminals in 1968. Connect one to a mainframe computer system and you have an interactive command-line interface that can be used to write programs, run software, and control machinery. At Lakeside, their teletype was plugged into a phone line through which the students were able to dial into a General Electric 635 mainframe computer at an off-site location. The school was billed by the minute for the time the students spent connected to the mainframe.

This type of set-up was called timesharing, a technology developed in the mid-60s for a world in which there were far more people who wanted to use computers than there were actual computers to use. Timesharing technology allowed one computer to service multiple users at the same time--as many as 50 concurrent users on some systems. It was over one of these teletype machines that Bill Gates and Paul Allen first met, and their shared life-long love of computers began.

Paul and Bill and their friends quickly exceeded Lakeside’s budget for renting computer time from General Electric. Fortunately, a Lakeside board member knew of a new computing company, Computer Center Corporation, that was installing a Digital Equipment Corporation PDP-10 in a storefront in the University District here in Seattle. Join me in the next installment to learn about our restored PDP-10 KA-10, maybe the last one operating in the world!