IT History Society Blog

An old, rare IBM film about SAGE recently surfaced on YouTube — what a fantastic resource that web site is. The film brought back many discussions I’ve had with my colleagues about the place of SAGE in the history of computing. Paul Edwards saw SAGE as the centerpiece of the “Closed World” of computing. IBM historians have discussed its role in propelling that company into the forefront of commercial computing after 1960. Others have discussed SAGE as the precursor of networked computing, a pioneer in graphical user interfaces, in real-time computing–the list goes on.

In 1989, the Smithsonian’s National Air and Space Museum opened an exhibit about computing and aerospace, and among the artifacts it displayed is a SAGE core memory unit. (The photo here is of a complete system on display at the Computer History Museum.) Not long after it opened, I took a retired SAGE engineer through the exhibit. When we got to the memory unit, he turned to me and said, “You know, it never would have worked. Had there been an attack, SAGE would have immediately become overloaded, and no signals would have gotten through.” Later on I mentioned this to another veteran of the project, who told me the engineer was flat-out wrong. We’ll never know. The Soviet Union never launched a bomber attack over the Nortth Pole. It is worth mentioning, however, that Paul Baran of the RAND Corporation proposed a scheme of distributed communications that, in his view, would be far more robust than SAGE’s top-down topology. Baran’s work is cited as a precursor to the packet-switched scheme that is the basis for today’s Internet. And despite a number of deliberate attacks, natural disasters, and other disruptions, the Internet has managed to be very robust as it has scaled up orders of magnitude over the past two decades.

It may be time for historians to have another look at SAGE.

Despite my dissertation research on Konrad Zuse, I’ve been accused of a bias toward the American side of computer history. Here are a couple of news items from the U.K. that may offset that. The first concerns what may be the first recording of music generated by a computer–the Manchester “Baby,” in 1951! That is 6 years before the famous Bell Labs demonstration, which was the inspiration for “HAL” in 2001, a Space Odyssey. Have a listen, courtesy of the BBC.

The second is an announcement of the opening of a new exhibit on Charles Babbage and his Difference Engine, at the Computer History Museum in Mountain View. As you may have heard, the Museum is exhibiting a working, full-scale replica, pictured here, of Babbage’s Difference Engine. Thanks to Alan J. Weissberger for this information.

These two items may help, but are not enough to give non-U.S. topics their due. Check with this blog for future posting that will address this issue more directly.

In an earlier post (March 20), I discussed Moore’s Law and its relation to the history of computing. Once again I feel compelled to return to the topic—this time, to discuss its impact, not on computer science and technology, but on its historians. Put simply, historians of technology, including me, find Moore’s Law unnerving. The existence of an exponential growth curve that has remained nearly constant since the 1960s goes against a basic tenet of the history of technology, namely that technical change (call it “progress” if you will) is not an autonomous force of nature, but rather “…a contingent construction shaped by political forces…” in the words of Tom Misa, Director of the Charles Babbage Institute at the University of Minnesota. Consider all that has happened in world politics, culture, and science since 1960. Consider the cultural upheavals in the United States alone during the single decade of the 1960s. Nowhere do these events affect the curve of chip density that Gordon Moore first noticed midway through that decade. What, then, is the driver of chip density, and by implication all that has resulted in computing from the steady, exponential increase in storage capacity and processor speeds for almost a half-century now?

Tom wrote those words in response to an article I had written, in which I suggested that perhaps the emperor of Social Construction has no clothes. I don’t believe that, but I was being provocative. Perhaps in partial response, the Babbage Institute has begun a study of Moore’s Law, which, I hope, will shed light on this question. I hope they invite me. But if they don’t, I’ll understand.