But memory was a different story. There was no Moore's Law for information storage, and the path ahead was anything but clear. On the contrary, four fundamentally different types of memory -- disk, tape, solid state (i.e., semiconductor) and optical -- all seemed to be vying for technology leadership, and all seemed to face insurmountable technical barriers. Disk drives, for example, for all of their storage density, also depended upon the worst kinds of old-fashioned electromechanical structures: spinning platters, twitchy little read/write heads, motors -- all the finicky, unscalable and retrograde technologies that the digital age was fighting to get away from. Tape was even worse. Optical needed tuned lasers and semiconductor memory, for all of its reliability and speed, was notoriously short on capacity.
No, these industry experts intoned, memory was the Achilles' Heel of tech, and someday soon -- probably by the late 1980s -- we would reach a point where the blazing speed of computer logic would be stalled forever by the limitations of memory, like a too-tiny carburetor atop a dragster motor.
But it never happened. And why it didn't is one of the towering intellectual achievements in the story of human ingenuity. For all of its inherent limitations, memory capacity managed to always keep up with the demands made by computer processors. And it did so not because one type of storage technology triumphed, but because none of them did. Instead, the last 25 years has been the story of the different kinds of memory all racing down the field, lateraling amongst themselves, handing off just before being tackled, and keeping the ball moving ever forward.
These days, the momentum seems to belong to disk memory, with chip-based memory (think iPod and Tivo) not far behind. Optical is still around, but tape has pretty much faded. Meanwhile, new memory technologies are starting to emerge -- what provoked my memory column three years ago was an announcement by the University of Wisconsin at Madison that it had found a way to store information on individual atoms of gold plate atop a silicon chip. One can assume that technology is quietly moving forward, as are some of the projects involving organic "bio-memory" that earned brief attention, then quietly disappeared. You can also be sure that if disk memory stumbles, one of these other technologies will step into take its place.
Looking back, those industry "experts" had every reason to be skeptical about the limitations of memory. None of this should have happened, and yet somehow it did. And if we still can't apply an empirical Moore-like Law to memory, perhaps we can finally say something like:
"Memory storage will always find a way to keep up with the demands of computation."
If that's a bit wishy-washy in terms of being able to plot the future on graph paper, it nevertheless says something profound about the nature of human ingenuity. Information storage technology researchers will never get buildings named after them, nor their pictures in the paper, nor the National Medal for Invention, but they are indeed heroes of our age. And their accomplishment will only grow larger over time.