Today in 1948, IBM’s Selective Sequence Electronic Calculator (SSEC) was announced and demonstrated to the public.“The most important aspect of the SSEC,” according to Brian Randell in the Origins of Digital Computers, “was that it could perform arithmetic on, and then execute, stored instructions – it was almost certainly the first operational machine with these capabilities. ” And from the IBM archives: “During its five-year reign as one of the world’s best-known ‘electronic brains,’ the SSEC solved a wide variety of scientific and engineering problems, some involving many millions of sequential calculations. Such other projects as computing the positions of the moon for several hundred years and plotting the courses of the five outer planets — with resulting corrections in astronomical tables which had been considered standard for many years [and later assisted in preparing for the moon landing] — won such popular acclaim for the SSEC that it stimulated the imaginations of pseudo-scientific fiction writers and served as an authentic setting for such motion pictures as ‘Walk East on Beacon,’ a spy-thriller with an FBI background.”

The reason for the “popular acclaim” of the SSEC, Kevin Maney explains in The Maverick and his Machine, was IBM’s Thomas Watson Sr., who “didn’t know much about how to build a electronic computer,” but, in 1947, “was the only person on earth who knew how to sell” one.

Maney: “The engineers finished testing the SSEC in late 1947 when Watson made a decision that forever altered the public perception of computers and linked IBM to the new generation of information machines. He told the engineers to disassemble the SSEC and set it up in the ground floor lobby of IBM’s 590 Madison Avenue headquarters. The lobby was open to the public and its large windows allowed a view of the SSEC for the multitudes cramming the sidewalks on Madison and 57th street. … The spectacle of the SSEC defined the the public’s image of a computer for decades. Kept dust-free behind glass panels, reels of electronic tape ticked like clocks, punches stamped out cards and whizzed them into hoppers, and thousands of tiny lights flashed on and off in no discernable pattern… Pedestrians stopped to gawk and gave the SSEC the nickname “Poppy.” The New Yorker magazine published a cover story on the SSEC and its public display. The machine influenced Hollywood, most famously as the model for the computer in the 1957 movie

EMERAC, the "Electronic Brain" in Desk Set

Desk Set…Watson took the computer out of the lab and sold it to the public.”

The SSEC had 12,5000 vacuum tubes and its various components would fill half a football field. But Moore’s Law was already evident to observers of the very young industry and Popular Mechanics offered this prediction to its readers in March 1949:  “Computers in the future may have only 1,000 vacuum tubes and perhaps only weigh 1.5 tons.”