It is clear that computers are getting smarter and smaller at an amazing rate and this is likely to continue. But for some time now computers generally have had the same form: a TV set and a typewriter keyboard with some extra box like accessories. Thus the main parts are input and output devices and they will surely change.
Two major changes in input and one in output have already begun. The use of joysticks and mice instead of the keyboard is the first change. Much more exiting is the increasing use of speech recognition. Speech for output has found limited application so far but it will grow with the use of speech input.
Aside from interface devices, what about the actual construction of the computer? To begin with, the photonic computers are on their way. These are computers which use light (photons) instead of electricity (electrons) to handle information. The very first computers calculated, stored, and communicated information with moving chunks of metal. They gave way to electronic devices which could be much smaller and faster since electrons are smaller and faster than chunks of metal. Our present electronic computers will, within the next decade, start to give way to photonic computers for just the same reason: photons are smaller and faster than electrons. Optical disks and optical fibers have already found major niches in the computer industry. Photonic transistor and memory components have been built and can only get cheaper until they become consumer products.
Feeding in to the use of photonic computers will be diamond fabrication technology. Diamond film has been fabricated by irradiating methane and other gasses with laser light or microwaves. Diamond is the ideal substrate and housing for photonic computers. It is transparent, insulating, very tough, and has extremely good heat conductivity.
Holographic images have appeared in popular magazines so their manipulation in real time by a photonic computer is a reasonable expectation. The ability to display three dimensional images carries with it the ability to project images in front of or behind the holograph. If images can be projected behind the holographic display then the display itself can be quite small and close to the eye.
So what does all this suggest as a reasonable form for the computer of tomorrow? Assume that people will want to have their computer with them and available at all times.
Since the visual display device can be small and close to the eye it can be like a lens worn over one eye. Instead of pictures on a solid screen, the viewer sees images projected at a comfortable distance. When used like a telephone it could project a realistic holographic image of whoever you were talking to so. The user could point to projected images or manipulate projected objects by hand instead of using a mouse or joystick. The computer will have sufficient vision to observe the location of the finger in space and relate that to the projected images.
Imagine that the lens which is worn over the eye has a tail, actually a tube, the end of which is inserted in the ear to allow the computer to talk to the user. Speech input can be picked up by bone conduction through the head. If the energy is available the tail could be prehensile enough to hold the lens in place. Two tails would be more comfortable and would enable stereo sound output. It this seems too bizarre, it could all be housed in a pair of ordinary looking glasses.
So our computer user of the future appears to be wearing a monocle. What is the experience like? First, the computer will engage in conversation with the user and have some ability to see the world around it. Next, it will have the almost magical ability to create visions for the user. This would be especially good for communications since a floating image of the speaker would appear, life size, in front of the user. Thus using a computer would be like having an imaginary companion who could not only talk, listen, and see, but who could also create visions of any sort imaginable.
The next step after this would be some sort of implantation but that will probably be a long while coming. What about all the other computers? Those that are not directly used by people can assume any shape at all. Microphones and speakers are tiny and cheap compared to keyboards and TV screens: they will come to dominate human interfaces. Separate visible computers may become rare as they are built in to present day mundane objects.