When did the computer truly become personal?

The first electronic general-purpose computer, ENIAC, was developed mainly for the US Army to assist with research calculations on ballistics. The ENIAC was a 30-ton behemoth with an 1800 square-foot footprint. An article in the Chicago Daily Tribune in 1946 announcing the war department’s unveiling of the ENIAC conveys a public attitude of awe and amazement–a machine that could perform 5,000 additions per second. Today’s computers (and smartphones) measure in the billions per second. But the point is that the ENIAC, like most early computing machines, was viewed by the public as a device used for important, top-secret calculations and scientific research. Today that attitude has shifted to super computers, while the ordinary computer, smartphone, or tablet (a “super computer” compared to the ENIAC) has taken its place in our pockets and backpacks.

What developments in technology caused this shift from the computer’s revered status to its relegation to a device for tweeting what you ate for dinner?

Has the PC’s role as the “personal computer” come to an end with the widespread adoption of “post-PC” devices such as smartphones and tablets?

What is the real personal computer of today? I would argue that it is the smartphone.

How did smartphones become mainstream? (adoption rates, etc.)

What was the public attitude surrounding the release of the first iPhone in 2007 compared to the release of the ENIAC in 1946?

How did computers transition from a novelty–something only used by experts–to something many people find essential to their everyday routines today?

My argument is that the release of the 1st generation iPhone sparked a movement to the post-PC era. It was one of the first widely-adopted smartphones to exist and one of the first to incorporate multi-touch technology. But it almost didn’t go as planned; after over two years of research and development, the iPhone still wasn’t working on the day it was scheduled to be demoed for the world. It was a make-or-break moment–if the iPhone made an unfavorable impression on the public, what would have happened?