On a Tuesday morning in December 1992, a Federal Express courier making the rounds of Boston-area tech companies dropped off a package. Inside was the heartbeat of our second-generation cable modem, a key to our broadband vision. I peeled back a protective sheath to find a handful of miniaturized integrated circuits, gateways to a long-imagined future. These innocent-seeming rectangles would determine whether LANcity succeeded in transforming the nation’s cable television infrastructure or disappeared into the start-up cemetery after failing to meet a technical milestone enshrined in our deal with DEC. A payment of $557,000 from our partners at DEC hung in the balance.
What Was LANcity’s Breakthrough in 1992?
In December 1992, LANcity successfully transmitted its first data packet through a second-generation cable modem. The test proved broadband could run over cable TV lines, leading to live video streaming demos, new funding from DEC and the start of modern cable internet.
A City in Miniature
I handed the new chips to my colleague Mike Sperry, who set off on an hour-long drive to Westborough, Massachusetts, where earlier we had handed our contracted hardware manufacturer, Design Circuits Inc., a set of customized, printed circuit boards. To buy time, we had designed and assembled these intricately architected boards in parallel with our chip development work, leaving an empty position near the center of a green surface where the new chips would nestle.
Up close, the new circuit boards for our second-generation modem looked like miniature cities: neatly arranged streets and pathways leading to a succession of vibrant colors and geometric shapes; inductors that looked like miniature doughnuts wrapped in thin red wires, edging up against a neighborhood of tan-colored, cylindrical capacitors; and rectangular multiplexers with neat, dark-gray edges sharing space with pin-like diodes decorated by colorful end caps. I was mesmerized by the intricacy we’d created and the connectedness of it all; how each tiny component played its own vital role in governing the flow of electrical currents. Remove any of the hundreds of piece parts and the whole thing collapses.
Each chip was equally meticulous from a design standpoint, sprouting 160 conductive pins that connected to corresponding slots. Because of their physical intricacy, it took three days to position the chips delicately. Mike kept in close touch with our manufacturing partner, monitoring the progress like a nervous parent as the chips were carefully put into place. Three days later, he drove back to Westborough, picked up the newly altered boards, and returned them back to our office. We’d asked DCI to populate three sets of circuit boards, reserving a pair of our sample chips untouched. Just in case.
Proving the Concept
After a series of preliminary tests, we were left with one last big question: Could we pass data packets through our modem? As in, in one side, out the other — a microcosm of the way IP data would flow across cable television lines in the real world. In other words, does the modem we’ve spent years of our lives on actually … work? We’d spent nearly a month doing everything to our modem except transmitting packets— the basic premise of TCP/IP protocol. Now, it was time.
It began with a “send” command from a keyboard attached to one of our Sun workstations. Cindy Mazza had a front-row seat in the action. One of the 13 original employees of LANcity, Cindy was a determined, diligent software developer, seemingly always a step ahead.
What Cindy was not, however, was the most vocal member of our team. She was our quiet warrior. Her most common auditory contribution was the steady tapping of a keyboard. It was surprising, then, that the first thing I heard was a vowel-intensive yelp of pure, unbridled, extemporaneous joy, straight from the throat of Cindy Mazza. No Celtics fan could have ever delivered a more convincing whoop of victory. She had been sitting in front of a workstation monitor, six or seven of us hunched closely nearby. Because of this, she enjoyed a close-up view of what had just happened during a moment that will live forever in my heart.
When Doves Fly
In an instant, there it was: the digital fingerprint of a single, lonely data packet flashing on a connected monitor. The small speck of data had passed through our software and our new silicon. One tiny, isolated, measly packet, a drop in the digital ocean. But it was all we needed to see. It had traveled unblemished, traversing not just the interior of a new siliconized cable modem but across time itself: Years of intense, demanding work powered by unrelenting conviction. The outburst rang out like a shot, expressing aloud the greatest “wow” moment of my professional life.
A final lab trial followed as we tested our cable modem over the mock cable system we’d installed in our own lab. Knowing that digitized video content presented challenges for data networks because of the density of data packets, Chris Grobicki and I arranged to use a brief video clip of a flying dove, stored on a CD- ROM disc, as a proof point before arranging a handful of real-world modem implementations.
Huddling in a cubicle, Chris and I waited nervously to see if our dove would fly over our in-house cable system. In a flash, there it was: our broadband bird, feathered wings flapping, the video stream shooting across our amplified run of cable into our LCB modem through the innards of a connected computer and, now, onto a screen in high-resolution splendor. We could see individual feathers bristling. The image was gorgeous, a kiss from an angel.
The Cable-Driven Future
Within days, we were flooding our system with waterfalls of data, watching like proud parents as bitstreams flowed without interruption from the powerful packet generator. Our new cable modem — software, new silicon, our new RF tuner, our Unilink-II protocol, the entire stack — was working. We’d earned another cash injection from our partner DEC.
By now, we had done enough testing to know we could confidently say “go” to our volume chip-manufacturing schedule. Thankfully so: Our relationship with DEC, and the funding behind it, depended on signing our first paid customer for our next-generation modem by August. Now, with our dove flying and our tests conclusive, we had the confidence to pivot immediately to field tests over several working cable systems.
Image: West Virginia University Press
We also staged a few personalized demonstrations. Working with DEC, we rigged up the home office of a professor at the Massachusetts Institute of Technology who had expressed reservations about whether our technology would work. We’d connected our new modem to the cable system that served his neighborhood and invited him to download to his computer a high-resolution video displaying the launch of a NASA space shuttle. Accustomed to the slow grind of low-speed modems and phone lines, our friend from MIT was about to leave to take a shower while he waited for the file download to complete. But as he glanced back at the monitor, he discovered the video was already on his screen: proof of our broadband vision, playing on an infinite loop.
The following is excerpted with permission from The Accidental Network, copyright 2025, by Rouzbeh Yassini-Fard. Reprinted with permission from West Virginia University Press. All rights reserved.