The Machine That Changed the World is actually the title of a well-known book about the history of Toyota's lean manufacturing and the importance of the automobile industry (and is fascinating in its own right). Something that changed the world that really is a machine, is the Xerox Alto. My First Encounter On my first visit to the US, in 1979, I attended the Symposium on Operating System Principles in Pacific Grove. I then went down to Caltech to visit Carver Mead's group there, which was being run by a colleague from Edinburgh on sabbatical. The following week I visited Xerox PARC (which is hidden in a small valley just off Page Mill Road). PARC was already legendary for many things such as Ethernet, laser printers, and distributed systems (my Ph.D. was on the design of distributed file systems, hence I had no difficulty scoring an invite there). But the thing that I think was most influential was the Alto. This was a personal computer, with a network interface, a high-resolution bitmapped display, and a mouse. Xerox had set up PARC in 1970 with a view to building "the office of the future". It turned out that neither Xerox nor the team that they assembled knew what that meant. But, as Bill Joy said (later, he wasn't at PARC as far as I know, although he was at the Pacific Grove operating system meeting) "the best way to do research is to make a radical assumption and then assume it's true." The radical assumption that PARC made was that computers would continue to get cheaper and cheaper, and so they should build what they thought people might have ten years into the future. They also had what Donald Knuth called the "greatest by far team of computer scientists ever assembled on one team." They were not starting from scratch. Some extremely influential work had been done up the road at the Stanford Research Institute (SRI) that had resulted in... The Mother of All Demos The name came later. But the Mother of All Demos was a demonstration given at the ACM/IEEE Fall Joint Computer Conference in San Francisco on 9th December 1968. It was presented by Doug Engelbart. In an hour and a half, he presented many of the fundamental building blocks of a modern PC/Mac/workstations: windows, graphics, mouse, word-processing, high-performance networking, hyperlinks, collaborative software, and more. Probably only the mouse was truly new (the first mouse was a wooden block with a single button—see the SRI picture to the right), but this was the first time that all these elements had been put together into a single system. The computer scientists at PARC were heavily influenced by this, and in turn, the Alto influenced the Apple Macintosh and Microsoft Windows, which influenced smartphones...but we are getting ahead. The Alto The Alto was created by a team of about 35 people, led by Chuck Thacker on the hardware side, and Butler Lampson on the software side. Its development cost about $10M in today's dollars. The screen had 0.5M pixels (although they were not yet called that), 72 pixels per inch, black and white only. The network, the original Ethernet, ran at 3Mb/s. The mouse had 3 buttons. Of course, there was also a keyboard. The processor ran at 0.3 MIPS, with 128KB of RAM, and a 2.5MB disk (no, that is not a misprint, just a couple of megabytes per removable disk cartridge). The table above is from a Butler Lampson presentation in 2006 comparing the Alto to a contemporary PC. Since that was over 10 years ago, you can add your own additional scale factors to compare it to a modern laptop or a smartphone. Interestingly, 2006 was pretty much the end of clock frequency scaling. PC clock rates are still 3GHz, we just have multiple cores. The Alto debuted on 1st March 1973, so about 10 years ahead of similar capabilities being available, first on engineering workstations, then on the Mac, and finally on the PC with Windows. The Alto was introduced to Xerox management on 10th December 1977, along with its software capabilities. The occasion was Xerox Future Day where Xerox was searching for how to grow after copiers. PARC hoped to persuade Xerox to produce a commercial version of the Alto. In fact, they did introduce a product, called the Xerox Star, in 1981 but it was too expensive at $16.5K (over $40K in today's dollars) to be a success. It would take another couple of turns of Moore's Law to get the price of a personal computer down to $2.5K with the first Mac (still nearly $7K in today's dollars). Of course, the story about Steve Jobs visiting PARC in 1979 is well known. Everything he saw was well-known and public in the computer science community, but seeing a real demo—in the same way as the Mother of All Demos had blown everyone away—make a big difference. I was amazed myself on my own 1979 visit. Don't forget that this was largely still the era of alphanumeric terminals and no graphics. There was a video of Steve Jobs talking about visiting PARC. He said that there were three big things at PARC, but he was so blown away by the graphics that he didn't see object-oriented programming or the networking. He just saw the graphics, the mouse, the overlapping windows and all the stuff that we are now familiar with. Forty Years Later Forty years to the day after that 10th December 1977 was a couple of weeks ago. The Computer History Museum organized an event featuring two forty-year-old Alto computers. Not only that, it featured half a dozen of the original engineers who created the Alto and the software that ran on it, who ran the demos. I will write about that in tomorrow's post. Sign up for Sunday Brunch, the weekly Breakfast Bytes email.![]()
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