In the late 1940s, magnetic tape was showing its usefulness in the audio recording industry, and Thomas J. Watson Jr., then executive vice president at IBM, felt it was time to explore magnetic tape as a data storage medium as well. But the tape was too fragile and prone to breakage if run at high speeds—it had to start and stop quickly as data was recorded and read. Before magnetic tape could become a viable storage option, a method for protecting the tape from breakage had to be invented.
IBM engineer James A. Weidenhammer was part of the IBM team looking for an answer. He tried using a vacuum cleaner to blow air onto the tape in the hopes that it would form the tape into loops and prevent it from binding and breaking. It didn’t work. But then, Weidenhammer recalls, “for some reason or other I just switched things around ... and it worked much better.” The vacuum pulled the tape down from the bottom of the column, keeping the tape from sticking and breaking during the rapid accelerations and decelerations. Its use in the IBM 701 signaled the beginning of the era of magnetic storage, for its buffering technique would become widely adopted throughout the industry.
Magnetic tape becomes a viable solution
“It was a unique solution that provided essentially uniform tensions across the tape and allowed the tape to be brought up to full speed in 7.5 ms on the first two systems, and around 1 ms in later ones. The gentle handling enabled the use of more fragile, but lighter, plastic-backed tape. This was an unbeatable combination for high-performance tape systems and was used from the 1950s through the 1970s.”
Magnetic Recording: The First 100 Years, page 258