The origins of the Mac
How the mother of all demos led to the computer that changed everything
Exactly 50 years ago, without any fanfare, unnoticed by most, unrecognised even by many who were right there in the room, the future arrived. It was 9 December 1968, a Monday. At the Fall Joint Computer Conference in San Francisco, Douglas C Engelbart gave a presentation of a revolutionary approach to computing, which demonstrated for the first time a whole complex of concepts fundamental to computing as we know it today – a windowed interface with which you interact using a keyboard and mouse, direct on-screen text editing, copy and paste, and much more. Bear in mind that at the time, a computer filled a room and cost hundreds of thousands of dollars, and the usual way to interact with it was to have a technician feed it punchcards or load spools of paper tape. Engelbart’s demo was run off a room-sized, time-sharing computer 30 miles away over a leased line link-up, but it wasn’t the computer he was demonstrating. It was interactive computing, a radical new way of using a computer, in contrast to the standard number-crunching.
The presentation is now known as “the mother of all demos.” It was given that name in a book by tech journalist Steven Levy published in 1994; the common Middle Eastern “mother of all...” idiom had become current in the West when Saddam Hussein threatened “the mother of all battles” in a speech during the first Gulf War in 1991. The book was titled InsanelyGreat:TheLife andTimesofMacintosh,theComputerThatChanged
Everything, and in it Levy made the connection between Engelbart’s demo and the way the Mac worked. It was, in numerous tangible ways, the prototype of the Macintosh. Vannevar Bush and the memex Not that Engelbart’s ideas sprang out of thin air: his entire career had been inspired by the ideas of Vannevar Bush, who published an article in 1945 in TheAtlantic magazine entitled As We May Think. The editor of TheAtlantic explained in an introduction, “As Director of the Office of Scientific Research and Development, Dr Vannevar Bush
has coordinated the activities of some six thousand leading American scientists in the application of science to warfare.” Looking forward to when the fighting has ceased, “[Bush] urges that men of science should then turn to the massive task of making more accessible our bewildering store of knowledge.” In his article, Bush pictured a time when “The
EncyclopediaBritannica could be reduced to the volume of a matchbox. A library of a million volumes could be compressed into one end of a desk.” Essentially, he conceived of vast amounts of information being digitised, as we’d describe it today, and extrapolated from the very limited technologies of the day to speculate how this might be done – for example, he cleverly postulated a method of “dry photography” analogous to the way a television screen works. The desk containing all this information, he envisaged as “a sort of mechanized private file and library,” which he dubbed a “memex”. “While it can presumably be operated from a distance, it is primarily the piece of furniture at which [somebody] works. On the top are slanting translucent screens, on which material can be projected for convenient reading. There is a keyboard, and sets of buttons and levers.
“Most of the memex contents are purchased on microfilm ready for insertion. Books of all sorts, pictures, current periodicals, newspapers, are thus obtained and dropped into place. Business correspondence takes the same path. And there is provision for direct entry.” The user would then navigate through the stored material by tapping a code on the keyboard, and use levers (or a joystick much like the controller on a modern microfilm reader) to move forward or backwards, to find the desired information and then display it.
More than this: the user would be able to add annotations and links to other material, building “a trail of his interest through the maze of materials available.” With a trail saved, it could then be followed again later and even shared with other people to follow. In this way, the vast mass of information could be navigated through, selected, interpreted and understood much more readily.
Augmenting human intellect
Doug Engelbart read Bush’s essay as a young radar technician stationed in the Pacific. Some years later, it inspired his choice of career – or, as he called it himself, his crusade: he would find a way to use technology to augment human intellect.
Engelbart earned a PhD in the emerging field of computer science and joined a think tank called Stanford Research Institute (SRI), where he set up a group named the Augmented Human Intellect Research Center, later called simply the Augmentation Research Center or ARC. The group developed its On-Line System (referred
Doug was looking for a way to use tech to augment human intellect
to by the not-quite-acronym NLS). Then, with his funding getting tight, Engelbart booked a last-minute slot at the conference to present NLS to the world.
It was a huge gamble, and a remarkable technical feat to coordinate cameras and audio feeds over a leased line, with multiple simultaneous operators miles apart in different locations. But the demo gods were gracious and, amazingly, it went without a glitch.
The demo wasn’t about the computer he was using, but in one crucial respect it was about the hardware: Engelbart was using a mouse. If he is remembered today, it is as the inventor of the mouse – he was granted US Patent number 3,541,541 for his “X-Y position indicator for a display system.” This makes it clear how the device worked: it had two wheels inside, mounted at right angles to each other, each attached to a potentiometer to measure how far it turned. When the user moved the mouse, one wheel would detect movement in the X direction and the other movement in the Y direction, making it easy to calculate where to move the on-screen marker relative to its starting point.
Instead of the wheels themselves making contact with the table, later evolutions of the mouse would have a roller ball (an innovation developed by one of the 17 members of the ARC team, Bill English, who constructed the first mice with Engelbart), but the basic principle was the same, at least until the optical mouse was invented.
In the demo, Engelbart was apologetic about the name of his pointing device: “I don’t know why we call it a mouse. It started that way and we never did change it.” You only have to look at his mouse, though, to see why – in its early development the cable attached at the bottom, at the opposite end to the buttons, so it looked just like a small creature (admittedly rather angular in shape) with two eyes and a nose at one end and a tail at the other.
The cable was moved to the button end when testing established that it tended to get caught up in the user’s sleeve and generally get in the way, but at one point in the demo, when Engelbart handed over to another of his team, Don Anders, working at SRI in Menlo Park, you can clearly see that Anders was using the old-style mouse with its cable at the bottom.
Other terms used by the ARC team have not stood the test of time. For example, they call the on-screen position marker a “bug” (and joke about “bug fights” when there are two users sharing a screen) but of course a computer bug is a completely different thing today. The NLS position marker, more formally referred to as a “tracking
spot”, was a relatively crude indicator, too, not an elegant arrow like the familiar modern pointer, and it did not transform into a text insertion cursor or anything else.
A window to the future
Of course, a pointing device is… er, pointless without a graphical environment, and that’s the other side to Engelbart’s achievement. He invented not only the mouse but the windowed interface that it operated upon. During the demo, his face was projected on one side of the huge screen at the front of the auditorium and his CRT’s display on the other, but that was just for show. NLS’s interface itself could be separated into distinct zones – at one point, it had a video feed of a remote co-worker in the top-left quadrant, the area for typing commands next to it, and the shared document they were both viewing in the half-screen below.
Engelbart began the demo by typing words on a white screen, deleting some, then copying and pasting some. He was interactively manipulating ‘documents’ on screen. Then he went further. Having pasted a block of text several times to create more text than would fit on his screen (which, significantly, it did not seem possible to scroll down), he hid the text of each paragraph except for its first line (much as modern word processors might switch from full text to outline view). He wrote a shopping list and reordered it to group similar items (types of fruit together, canned goods, and so on), and then toggled between showing only category headings and the full list. He recategorised items, then showed and hid numbering, which appeared to be added automatically. He displayed a diagram of the shops he needed to visit, and selected one to view the items on his shopping list relevant to that location. Today, of course, we call this hyperlinking.
He returned to this kind of hyperlinking later in the demo, showing how easy it was to navigate a nested hierarchy of key terms, with selecting each term opening up a linked branch or a new level of further information. The ARC team used the system for its own “planning, designing, debugging and documenting,” but Engelbart emphasised how structuring info like this was a way of organising thought and “representing information structures that linear text cannot represent.”
Some years later, computing pioneer Alan Kay noted that there were precedents for some of this, including multiple windows and display text editing on a bitmapped screen, but the NLS demo pulled it all together and showed it all working. It wasn’t Vannevar Bush’s desk-sized memex
The demo displayed interface zones and an early form of hyperlinking