Today in 1981, IBM announced the IBM Personal Computer, model 5150. The PC featured a 4.77MHz Intel 8088 CPU containing 29,000 transistors, 16KB RAM (64KB standard, expandable to 256KB), 40KB ROM, one or two Tandon brand 5.25-inch floppy drives (160KB capacity), a mono display, and an optional cassette drive. The base price was $1,565 but a fully loaded version with color graphics retailed for $6,000. Over 65,000 units were sold in the first four months.

The IBM Archives put this in perspective: “Two decades earlier, an IBM computer often cost as much as $9 million and required an air-conditioned quarter-acre of space and a staff of 60 people to keep it fully loaded with instructions. The new IBM PC could not only process information faster than those earlier machines but it could hook up to the home TV set, play games, process text and harbor more words than a fat cookbook.”

And Kevin Maney in Making the World Work Better: “Within two years of its introduction, the IBM PC took over the Apple II as the best-selling PC. By 1985, IBM’s PC division had grown to 10,000 people and was grossing $4.5 billion a year… As the power of computing dispersed into the hands of individuals, computing changed profoundly. Computing kept moving inexorably outward, from the experts to the masses.”

According to IDC, PC shipments peaked in 2011 at 363 million units. In May 2013, IDC predicted that tablet shipments will exceed those of portable PCs in 2013, as the slumping PC market was expected to see negative growth for the second consecutive year. In addition, IDC expected tablet shipments to outpace the entire PC market (portables and desktops combined) by 2015.