Pacific Connection(英語)

When Bits Were Stored on Vacuum Tubes: The Computer History Museum

The Computer History Museum bills itself as the world's largest collection of computer-related artifacts. It resides in the heart of the Silicon Valley, California's technology epicenter. Yet most of the motorists driving nearby on U.S. Highway 101 have never heard of the museum, much less seen it. That's because it is hidden away at Moffett Federal Airfield, a sprawling former naval air base now operated by NASA, the National Aeronautics and Space Administration.

The museum has found a new home and is scheduled to open this spring. But for now, a visitor first makes an appointment, then drives up to a checkpoint and shows his American driver's license (or Japanese passport) to the guard. Entering the base, he turns right at Hanger One, built in the 1930s to house a dirigible and big enough to contain three Titanics side-by-side. The museum's viewing collection is housed in a nondescript edifice known as Building 126.

Inside, Building 126 looks at first like the ultimate used computer sale, with hardware lining the aisles. Shades of industrial grays, greens and blues predominate, and banks of vacuum tubes and transistors are everywhere. Almost nothing is behind a glass case: the machines look much the way they did when they were state of the art.

The museum first tried to arrange the collection in chronological order, starting with some 16th century calculating instruments, moving through the first computers of the 1940s, the business and scientific mainframes of the 1950s and 60's, and the early-generation desktop machines of the 1980s, and ending, as for now, with a handheld PalmOS/cellphone combination. But as the collection grew, that attempt at organization was scrapped. To follow the timeline, you must move back and forth from one side of the building to the other. There is much to see, yet Building 126 represents only about 10 percent of the collection. According to the museum's curator, Mike Williams, the collection is probably larger than that of the Smithsonian in Washington DC, the London Science Museum, and the Deutsches Museum in Munich-combined. "You can probably throw in the Heinz Nixdorf Museum?plural? Forum in Paderborn, Germany, as well," he says.

Why collect all these electronic dinosaurs, so cumbersome to program, so difficult to maintain, and, despite their size, so primitive in terms of compute cycles, memory and storage? "The computer revolution is as important as the industrial revolution," says Williams. "Whereas the first amplified our physical abilities, the second amplified our brain power." This is really the age of the computer, he says, and for that reason alone, we should know how got we got here. And yet, technology has changed so fast that preservationists have scarcely kept up with the turnover.

Seeing these hulking machines "in the flesh" drives home the speed of technological change in a way no written chronicle can. Some of the early computers are the size of industrial stoves, automobiles, even small buses,. They are the information age's steam engines. You can stand eyeball to vacuum tube with one and easily imagine it surrounded by the proverbial "men in the white lab coats" responsible for its care and feeding. Then you can walk to the next room and compare it with first-generation desktop computers, small enough to stuff into a car and be smuggled into the workplace by the first generation of users. These pint-sized machines came on the market just a few decades later. The contrast in size makes you realize just how fast the semiconductor revolution democratized the technology.

From Boston to California

The core of the museum's collection began at the home of Gordon and Gwen Bell. Gordon was an engineer for Digital Equipment Corporation, working on the PDP and VAX minicomputers. When the collection outgrew the Bell's home, it moved to the large lobby at DEC, where it became known as the Digital Computer Museum. In 1983, the collection moved to downtown Boston, where it shared space with the Children's Museum. But over time, the focus shifted from computer history to technology education, and funding grew scarcer.

Enter Len Shustek, semi-retired entrepreneur and occasional Stanford University lecturer. "He often brought artifacts into his classrooms to show people how the development of computers began," Williams recalls. "He started dreaming of a place that could house a larger collection. Silicon Valley was the obvious place." In 1996, Shustek arranged for inexpensive housing at Moffett, which became a West Coast affiliate. By February 2000, the remainder of Boston's historical collection had shipped to California, and the Computer History Museum became an independent institution. The museum now has 3,500 artifacts, 3,000 films and video tapes, and 5,000 photographs. While the high cost of transportation has kept most of the collection domestic, Germany, Great Britain, and Switzerland are represented, as is Japan. The museum's holdings include equipment from Fujitsu and NEC, including an NEAC 2203, an early, large transtorized machine.

But the disadvantages of being housed on an air base are starting to show. The location is inconvenient and obscure. Visitors need a docent to view the collection. And the non-public warehouses are crammed with floor-to-ceiling pallet racks. You wouldn't want to be there in an earthquake. This spring, the collection moves once more-this time to what appears to be a permanent home, a 119,000 square foot building just off the highway. Constructed in 1994, it was one of two buildings sold by SGI. The flagging fortunes of the graphic workstation/server maker will be the museum's gain.

From garages, yards and eBay

Much the collection now comes from people working for companies and institutions, who saved outdated equipment from the junk heap by storing it in their garage. And then there is the museum's rarest computer, the Johnniac. Built by the Rand Corporation in Santa Monica, California, in the early 1950s, the Johnniac was given to a museum in Los Angeles, which, after a few years, dismantled it and put it outside. There it was, waiting to be hauled off, when Keith Uncapher, one of the machine's original builders, spotted it. "He called us and we rescued it," says Williams. "This kind of thing happens often." The Johnniac is imposing, with six sets of glass doors covering a nest of racks, wires, resistors, and capacitors, all hand-soldered in 1953. Rows of vacuum tubes each stored one bit.

Another rescue: a mainframe built by Gene Amdahl when he was a graduate student of Physics at the University of Wisconsin. Amdahl mainframes later competed with IBM's but this hand-soldered model was built in the 1950s, long before he started his own company. The cabinet has one unusual feature: bullet holes. "The machine was dumped into somebody's backyard and used as a base for target shooting," Williams says. "Some of them missed." Gene Amdahl is now on the museum's board of directors, and his machine is safely in the collection.

DEC has given the museum its entire corporate archives of documents and photographs. Tandem has done the same. And HP, which now owns both companies, has donated a variety of recent equipment, including laptops and scanners. Some machines are purchased over the eBay auction site, such an IBM 604, IBM's first massed-produced electronic (as opposed to electromechanical) computer. A group of volunteers now monitors eBay, bidding for modestly priced equipment in the $15 to $50 range.

The museum also maintains a large collection of software, emphasizing operating systems and compilers, most of which are stored on the original medium. The exception is software that arrived on punchcards, which are vulnerable to humidity. The cards are kept, but the code are archived onto CD-ROMs. The museum also collects landmark applications like Photoshop and the early spreadsheets.

"We get anywhere from six to two dozen offers each week for computers, software, books, photographs, and videotapes," Williams says. The museum doesn't automatically rule out anything, nor does it maintain a shopping list of things it especially wants. Instead, Williams and his volunteer collector's group meets every Monday. "We methodically work our way through the offers, saying 'no thanks,' 'no thanks,' 'no thanks'--and, 'oh yes we'd love to have that.'" A few items are clearly beyond the museum's scope, like a working scanning electron microscope that is now in possession of the Smithsonian.

Like a fine arts museum, the Computer History Museum also loans pieces of its collection out. A Univac is currently on exhibit at the Museum of Science in Boston. An early DEC PDP-1 is traveling through Europe in an exhibit organized by the Barbican Museum in London.

Not just chunks of metal

Williams himself is one of the museum's more unexpected additions. For 30 years, a computer science professor at the University of Calgary in Canada, he woke up one day to discover he had become that rare thing in an industry that always looks forward: a historian. He has written books, published numerous papers, and been editor-in-chief of the IEEE Computer Society's Annals of the History of Computing. After taking an early retirement, so as to have even more time to write, Len Shustek called. Shustek, by then the museum's board chairman, wanted to talk about a curator position. Would Williams move to California? Summer was gone, and winter in Calgary is cold enough for the town to have hosted an Olympics. Williams thought about the California sunshine and said yes.

There are curators specializing in paintings, in sculpture, in rare books and stuffed animals. Williams is now one of the few curators specializing in antique computers. "I'm also responsible for the interpretation-that's not just a refrigerator over there. It has a story and there are people behind it. Without those stories, the computer is just miscellaneous chunks of metal."

While most of the machines are unpowered, the museum occasionally brings one to life. That was the case of an IBM 1620, a sentimental favorite because, for a generation of students in the early 1960s, it was the first computers they ever programmed. For more than two years, volunteers disassembled the machine, tested each component, and reconstructed it, keeping detailed records of the process. They sought parts on the Internet, including a monitor typewriter, which they reconditioned. The museum's IBM 1620 now runs again.

One of the biggest pieces of hardware of the collection is actually a piece of something much bigger: the SAGE, a sprawling military machine used for monitoring radar for NORAD, the North American Aerospace Defense Command. (The museum's largest complete computer is the IBM 7030, also known as "Stretch.") The SAGE is the predecessor of the today's air traffic control system. But by 1984 when this one was decommissioned, it was an anachronism, a vacuum tube monster, consuming about a million watts, still running in the age of the semiconductor. Each Sage center had two computers, with 22 SAGE centers around the country.

"The original IBM PC probably had as much power as this great big thing, which took up about the size of a football field," says Williams. And then there was the problem of maintaining the computer's 50,000 vacuum tubes. "Vacuum tubes burn out on a regular basis, which is why they kept two machines going. Yet tubes had long been replaced by transistors and integrated circuits. So the military bought their vacuum tubes from the only place in the world that still made them-Czechoslovakia in the Soviet Union. The whole of the North American Air Defense System was predicated on Eastern Bloc spare parts."

Yet the SAGE had a few features that would carry over to the 21st century. Because tracking information had to be passed from machine to machine, the SAGE featured the first modems. The machine also featured an early pointing device, a light gun, which the operator would point at the radar screen to retrieve more information on a sector. The light gun was a precursor to the light pen, and ultimately, to the mouse.

The strangest computer in the collection was offered by the Texas gift company Neiman-Marcus, whose catalogs include high-priced fantasy items like a limited edition Lexus Bell helicopter. In 1965, the company offered a kitchen computer for tracking recipes. Sort of. "They took a standard Honeywell 315 and set it in a Jetsons-like pedestal," Williams. "It cost $10,600, which could have bought a three bedroom house back then." Kitchen computers have never caught on, but this one presented special challenges to the aproned wife pictured in the catalog photo. The machine had no keyboard or display, only binary code entered through switches. Output was via binary blinking red lights. Not surprisingly, none were sold, and the original used in the catalog photo now sits in the museum.

The museum has a Hollerith census taking machine, Cray-1 and Cray-2 supercomputers, an IBM 360, a German Enigma encryption machine, and a Swiss telephone booth featuring a computerized telephone lookup. One of the most recent pieces is the BEHEMOUTH, Steve Robert's cross-country bike with built-in computer and ham radio. The museum has an impressive collection of personal computers, including the classic Xerox Alto 2, the first with a graphical interface. There's an Apple 1-essentially a green circuit board and chips (but lacking a keyboard, power supply, and monitor)-which explains why the Apple 2 was so much more popular. Other small machines include an Osborne 1 "luggable" (about as portable as an anvil), an Apple Lisa-forerunner of the Macintosh, an Atari 800, and my first computer, a Commodore VIC-20..

All of this will be eventually be packed up and moved to new, more glistening quarters. Still, these workhorse computers have seemed right at home here. Building 126's no-nonsense warehouse decor complements the collection of big iron mainframes, built to crunch numbers, solve problems, track aircraft, and process cards-not surf the Web and play computer games. The new building, once a classic Silicon Valley cubicle-filled office, represents the new computer industry, both boom and bust. The new home will make the museum a must-see attraction of the Silicon Valley, and more visitors will find their way to its door, where they can visit without an appointment. The museum will also continue to be one of the few technology exhibits in the U.S. geared specifically for adults. There will be no buttons to push, no interactive displays teaching, at Williams puts it, "how zeroes and ones are stored on a chip." The museum will remain a place to preserve history, a chronicle of the days when bits were stored on vacuum tubes, data flowed through hand-soldered wire, and software was punched on paper.

Sidebar: A Call for Ideas from Japan

Old computers are big, heavy, and difficult to transport-which is one reason why Japanese technology is under-represented at the Museum of Computer History. But ideas can also be difficult to transport, which is why John Toole, the museum's executive director and CEO, would like to hear from readers of Software Design.

"With the move to the new building, we want to tell the story of computers as a walk through history," he says. That timeline exhibit is still in the early planning stages, represented only by a tentative cardboard model suggesting what the room could eventually look like, but not the story it will tell. " We're looking for help on how we should frame the history. For example, how should the supercomputer era be characterized from a Japanese perspective? That's a controversial topic, and we want to be sure we have all the bits and pieces. The same is true with the advent of minicomputers and the personal computer revolution."

If you would like to contribute ideas, or perhaps even a computer artifact of your own, please write John Toole at Curator Mike William can be reached at

The new museum will be located at 1401 Shoreline Boulevard in Mountain View. Opening is slated for this spring.