The computer is the most profound machine that we humans have ever created and ever will create. In the late 1940'ies, it was the newest and most advanced, but not essentially different from the other machines of the machine age, which had started cirka 200 years earlier with the invention of the steem engine. But it would soon come to rule them all and mark the beginning of a new age.

Before 1950, computers were operated, much like other machines, by connecting wires, pressing buttons and pulling levers. But by 1950 the operator no longer controlled the computer harware directly. Instead a new layer of abstraction, called software, had emerged, which was manipulated though special input and output devices. This hardware-software separation is what marks the transition into the new era of computers.

Since then there has been a major breakthrough in our relation with computers aproximately every nine years. I predict that apart from the eight milestones we have already passed, there will be five more, after which the computers will mark the transition from the age of humans to a new stage of evolution (if they will care about such things).
These are the milestones of the computer age:

1950: The human computer interface: The computer age dawns when software is clearly separated from hardware. The computer is operated by manipulating its software and studying its output through a human computer interface - typically consisting of a typewriter, a printer, punchcards and magnetic tapes.
1959: The terminal: The typewriter and printer are combined into an electronic device that can send input directly to the computer and present the output immediately on a screen
1968: The display: The advance of computer graphics makes it possible to display an abstract representation of a program state in both textual and graphical form. The program state can be directly manipulated through input devices such as the newly invented computer mouse.
1977: The personal computer: Computers have become sufficiently small, cheap, powerful and easy to use, that many people want to own a computer. From being exclusive to large coorporations and science labs, it now makes its entrance into regular homes and offices. TV-screen, keyboard and mouse become the standard human-computer interface.
1986: The portable computer: All parts of the computer can now be integrated into a foldable case that can be carried around. You no longer have to sit down by a desk to use a computer.
1995: The connected computer: Both the Internet and the world wide web have existed for a while, but this year it reaches the mass market. The internet boom coincides with the multimedia boom, giving the large public a rich experience of graphics and sound, both online and off-line.
2004: The mobile computer: Smartphones are taking over the mobile phone market and the iPhone is just a couple of years away. Everyone can now have a computer in their pocket.
2013: The ubiqitous computer: The most recent breakthrough, cloud computing, is less appearent for the end user, but it revolutionises creation and hosting of web applications. Most traditionally desktop based applications move to the cloud for a greater collaborative online experience.
2022: The wearable computer: The computer no longer has to be something you carry with you - you weare it; as a watch, glasses, jewelry or even implants. It is powerful enough on its own but can also connect seamlessly with the cloud and devices around it. Screens are cheap and expendable. They can be folded, laser projected or even generated on demand.
2031: The etheral computer: The cloud moves out from the massive data centers and into micro-servers all around us, connected wirelessly with eachother. It is no longer meaningful to talk about data as stored in a specific number of copies at specific physical locations. Instead we measure data in terms of accessibility, longevity and integrity.
2040: The neural computer: Naturally we will want to interface with the computer without the bother of having external devices that only can be accessed though sensory input and output. In the beginning of the 2040's, the techology is finaly ready to connect us to the computer directly on the nerves. We will be able to see, hear, smell, taste and feel the computer state and control it by pure thought.
About the same time, unemployment in the developed part of the world exceeds 50% as conputers and robots take over most physical and intellectual labour markets.
2049: The symbiotic computer: The separation between human and computer is getting more fuzzy as large parts of our brain are connected directly to the computer. We can no longer survive without it. New hybrid human-computer speices are being manufactured.
2058: The sentient computer: As human and computer fully merge into one speices, the symbiots, the computer becomes self-aware, but on a level that we cannot comprehend. If the human brain survives this stage, it will have the same relationship to the computer as our reptile brain has to the celebral cortex. Whatever part of our bodies that are needed to sustain whatever part of our brains that will be left, survives. The rest dissapears.
2067: The end of the human race: The naturals, those humans who decides to stay un-augmented by computer power, is enslaved and later exterminated as their utility for the symbiots subseedes the cost of keeping them alive.