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BERLIN -- The personal computer industry has torn up the rulebook.

Intellectually, I knew it was happening, but it was only after three days of intensive technology immersion at the IFA consumer electronics show that the magnitude of today's changes in personal computing really hit me. Here's some of the evidence that jumped out at me while at the conference:

Risky new designs are commonplace as new ideas about portability and multitouch percolate through hardware engineering circles. PC makers are betting on novelties including detachable keyboards, touch screens, and laptop-tablet hybrids.

Microsoft has transformed from a complacent laggard milking its Windows cash cow into a profoundly disruptive force pushing the market in new directions. Windows 8, Windows RT, and Microsoft Surface

The old guard of Hewlett-Packard and Dell are seriously challenged by newer arrivals such as Asus and Acer. Deeper down, ARM processors mean Intel no longer can take its market power for granted, either. And with iOS and now Android bubbling up in the tablet market, Microsoft must learn to act like an upstart, not an incumbent.

Apple, with its disruptive iPhone and iPad products and its influential MacBook designs, provides a sense of urgency: if the Windows allies don't bring profitable order to the chaos, Apple will.

In short, the PC market is experiencing something like a Cambrian explosion, a consumer-electronics version of the period more than 500 million years ago when a huge variety of dramatically different new life forms evolved.

Sure, most of those new species went extinct. And you shouldn't expect most of today's confusing profusion of new PC designs to survive.

But what you should expect is that five years from now, there will be more than just steady refinement of today's laptops and desktops.

Touch revolution

The biggest change by far in the PC market is touch.

Microsoft designed Windows 8 with a "touch-first" interface, meaning that it's not an afterthought added after the real work was done. Indeed, Windows 8 is so touch-first that I expect a lot of mouse users to be irritated initially.

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The PC here is following the mobile market, which has abundantly demonstrated the virtues of the direct physical interface. It's a natural human thing to reach out and manipulate things, even if glassy screens offer no tactile feedback and greasy finger smudges mar your view. Kids take to touch screens immediately for a reason: there's none of this detached indirection of the mouse and keyboard, where an action with one physical object in one place makes something happen elsewhere, on the screen.

I'm not convinced touch is for everybody or is worth the added expense in all cases. But I'm coming around. Dell's XPS One 27, a mammoth 27-inch touch-screen all-in-one computer introduced at IFA, can be pivoted into more of a drafting-table orientation that felt very natural for touch. Instead of reaching out awkwardly to a vertical screen, where your arms and fingers don't do well with precision movement, it's more like a workbench configuration.

Most of the touch screens are of course on otherwise conventional laptops, or on laptops that can be converted into tablets by flipping the screen around or detaching the keyboard altogether. Hybrids from IFA include Sony's Vaio Duo, Asus Transformer Book and Dell's XPS 12 Duo; keyboard-optional models included the Dell XPS 10, the HP Envy 2, and the Samsung Series 7 Slate.

I'm worried that hybrid and convertible designs will come with premium price tags, anemic performance, or failure-prone connectors and moving parts (PC makers to this day seem to have trouble even getting the basic laptop screen hinge right).

I also expect that these hybrid and convertible designs are for a smaller niche of the market -- the same way that Asus Transformer tablets or combining a Bluetooth keyboard with iPads aren't for everyone. Most folks today probably will be better served by having both an ordinary laptop and an ordinary tablet.

But whatever. I'm happy that people are rethinking what a PC should look like. And niches aren't always to be scoffed at. Heck, the first-gen MacBook Air was a niche product. You have to start somewhere, then build.

Windows RT and ARM chips

Essentially all tablets and smartphones today use processors based on ARM Holdings' chip designs, though the basic designs are modified by everybody from Apple to Qualcomm and manufactured by a range of suppliers. Now the ARM allies, aided by Microsoft with its upcoming Windows RT operating system, are trying to tackle the PC market where Intel's x86 family rules the roost.

The chief virtue of ARM chips is low power consumption and attendant long battery life, an essential attribute of tablets and phones and a big advantage over conventional laptops. Intel is working hard to get there with its own x86 chip designs that are ubiquitous in PCs today, but it's lost one big advantage, the software lock-in.

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It's work to take software designed for one chip and make it run well on another, so challengers taking on a company as powerful as Intel have had a hard time. Now, though, the software development world has a lot of experience with ARM designs, and Intel can't count on its x86 clout as so much of an incumbent advantage.

In particular, Windows 8 for x86 machines and Windows RT for ARM machines both use a Metro interface that abstracts away a lot of the underlying chip differences. Windows RT won't be able to run the gargantuan quantity of existing software for x86 Windows machines, but as Apple showed with iOS, it's possible to start afresh.

And some manufacturers are willing to give it a go. Dell's XPS 10 is a Windows RT machine, as is Samsung's Ativ Tab and the Asus Vivo Tab RT.

Windows RT is a risk, to be sure. Microsoft has profited immensely from the momentum of its installed base, but Windows RT starts from scratch.

Evolution

I expect the marketplace will cast aside plenty of the new designs. Likewise, during the Cambrian explosion, the crazy-looking Opabinia, with five eyes and a spiked proboscis, was one of many species that had only a fleeting presence on the earth.

But they weren't the only new life form from the Cambrian explosion; the compact arthropods called trilobites thrived for hundreds of millions of years afterward. Some of what looks weird today in the PC industry will look normal to fossil hunters of the future.