"A Walk Through 'Visible Storage'", section 4 of 6, by LEN SHUSTEK
From "CORE 2.3", a publication of The Computer History Museum.

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While Seymour Cray's companies were building massive supercomputers, Digital Equipment Corporation (DEC) was a pioneer in "mini- computers" for the masses. This PDP-8

Photo by Jessica Huynh
from 1965 was a huge success; for about $17,000 anyone could own a serious professional computer. You could even argue that it was the first "personal" computer, if that means a computer small enough for one (strong) person to pick up and put in his car!

By that definition, DEC had started by making decidedly non-personal computers like the PDP-1

Photo by Jessica Huynh
(display and monitor shown here), which had only 8K of memory, weighed a ton, and fit in no one's car. But DEC's machines were always approachable and touchable, and this one was the inspiration for one of the first computer games, SpaceWar!, which simulated dueling rockets ships on the circular display tube.

DEC went on to make many other medium- sized computers. One that set a standard was the 1978 VAX, of which we have several in the collection. For years rumors were floating around that certain eastern European countries had built clones of U.S. computers because they could build the machine and then steal the programs; software had as much value as hardware. After the fall of the Berlin wall and the collapse of the Soviet Union we were able to get this clone of a DEC VAX,

Photo by Jessica Huynh
made from U.S. and British integrated circuits and Eastern European circuit boards, all running purloined DEC software.

The computer revolution has been a worldwide activity, and our collection is appropriately international in scope. This Z-23

Photo by Jessica Huynh
medium-sized computer was built by the German Zuse Computer Company in the early 1960s. Its designer, Konrad Zuse, a formerly under-recognized genius of computer design, independently invented many concepts before WWII that were subsequently reinvented by others in different countries. But he lost that advantage to engineers from Great Britain and the U.S. because of Germany's war activities. His son, Horst Zuse, a computer scientist himself, has worked to restore his father's proper place in history and facilitated the donation of this machine to us.

The end of the flashing lights and whirring tape drives since then has made computers more efficient but much less photogenic.


Many people touring the Visible Storage Exhibit Area ask how many of our machines still work. The answer, unfortunately, is "very few." Even if we have complete hardware and documentation and the necessary software, it takes a huge effort to restore and keep the older machines running. But it can be done, and this IBM 1620,

Photo by David Pace
designed in 1959, is an example.

A dedicated team of Museum volunteers led by the indefatigable Dave Babcock worked for over a year to get this early transistorized machine back in working condition. As part of the project, they also created an exquisitely detailed cycle-by-cycle simulator that runs on the web. They collected a huge library of 1620 software of over 300,000 original punched cards, which were converted to modern storage and can now run on both the real machine and on the simulator. In the long term-think 100 or 500 years-the only consistent way to keep these old machines running and to preserve the accomplishments they represent will be to do it in "virtual space" through simulations.

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