COMPUTING

Putting Pen to Screen On Tablet PCs

Microsoft, despite hostility from competitors on other fronts, wins wide support for its proposed design standards

With the release next month of the first Tablet PCs produced to Microsoft Corp.'s general specifications, handheld computers may be about to leap into the ring with today's laptops. They will be about the size of the smaller laptops, will be at least as powerful, and—maybe their biggest selling point—will be able to handle handwritten text.

Microsoft has won support for its Tablet PC concept from an impressive collection of computer-industry heavyweights, as well as lesser-known players, including Hewlett-Packard, Fujitsu, Toshiba, Acer, Motion Computing, NEC, Tatung, Twinhead, Siemens, VIA Technologies, ViewSonic, and WalkAbout Computers. Each will launch its own version of the device in November, all built to run Microsoft's Windows XP Tablet PC edition. The Windows XP update customized for the Tablet PC has its own official unveiling on 7 November.

The Tablet PCs will be amply configured, general-purpose machines with more than enough power to run the full-blown Windows XP operating system. In particular, they will allow handwritten text to be entered onto a digitizing tablet and recognized, a functionality that's called pen-based computing [see photo, at right]. But there's much more.

"It's the wrong impression to think of these as just tablets," says David Ditzel, vice chairman of Transmeta Corp. (Santa Clara, Calif.). "This is the next-generation notebook computer."

"You've now got the full power of a PC and the simplicity of paper," amplifies Ted Clark, vice president of new notebook markets at Hewlett-Packard Co. (Palo Alto, Calif.). Transmeta makes the low-power-consumption Crusoe chip, which is being used in many of the Tablet PCs; H-P will offer the Evo Tablet PC under the name of Compaq, the PC maker it absorbed earlier this year.

Indeed, the Tablet PC will far outpace the computing power of existing small devices such as PDAs (personal digital assistants), including those variants based on Microsoft's own Pocket PC operating system.

Perhaps closest in horsepower to the new Tablets is another emerging category: the ultrapersonal computer, a keyboard-based notebook squeezed into a tighter form-factor and typically weighing well under 1.5 kg. Eventually, the tablet and the ultrapersonal may morph into computing cousins. The distinction is that ultrapersonals have keyboards but usually not tablets, the pad-like screen that gives Tablets their name, while Tablet PCs have tablets and may or may not also have keyboards.

Writing with "digital ink"
While Microsoft defined the Tablet PC by issuing a specification on what it should contain, it won't manufacture hardware itself. Any vendors that adhere to Microsoft's specs and pay it a licensing fee, said to be approximately US $15 000, plus a royalty on each unit sold, will be able to affix a Tablet PC logo to their systems.

All Tablet PCs will have electrostatic digitizer screens, enabling the pen-input feature that Microsoft has dubbed "digital ink," and all will run the Windows XP for Tablet PC operating system. All Tablet PCs also will have hot-docking capability for live connection to desktop PCs, quick security-setting features, and fast recovery from standby. Manufactuerers will differentiate their Tablet PCs by folding different features, like wireless networking connections and add-on keyboards, on top of a basic Tablet PC package.

Manufacturers also are incorporating assorted microprocessors that run on little power, aiming to maximize battery life in their own implementations. Fujitsu, Tatung, and Acer will use Intel's mobile Pentium 4. H-P and Antelope are going with the x86-compatible Crusoe from Transmeta.

The typical Tablet PC, then, will be the size and weight of the more compact laptops and sell for about $2000, a midrange laptop price. "We're positioning this as a laptop that's adding functionality [like handwriting recognition] to today's business notebooks [and] mobile platforms," says Andrew Dixon, group marketing manager at Microsoft. "Bill [Gates] thinks that within five years, the majority of PCs sold will be tablets," he adds.

The pen feature
"We've been working on it for over 10 years," says Microsoft system development leader Vamshi Reddy, referring to the ability of Tablet PCs to accept input scrawled onto their digitizing screens.

Before letters scrawled by a stylus can be recognized and grouped into words, software must digitize the input for analysis. The process is surprisingly compact: a full page of text can be packed into about 20 kB of memory.

"We're not just painting pictures," Reddy explains. "It's not bit-mapped. We store the actual points for cursive handwriting."

A multi-pass analysis follows. "It's an amalgam of techniques," Reddy says. "We use heuristics to look at the results from a few passes [through the digitized text], compare them, and then pick the most likely result, based on the context."

For example, an initial run through a recognition engine might assay position data of the digitized input, while a subsequent gesture-recognition engine plots the direction and the speed of pen movement for the same data.

For Microsoft, this is just the first step in a long-term strategy. "Moving forward, there will be deeper integration of digital ink technology into Windows XP and Office XP," says Dixon.

More ways to go
There are other handheld, pen-capable systems that—although not wearing a Microsoft logo—offer equivalent functions to Tablet PCs (and so are in fact "tablet PCs"). Of major interest are two separate designs that weigh in at a quarter of a kilogram.

The first, invented at IBM Corp., is called the Meta Pad. This handheld prototype has been licensed to, and will be marketed by, Antelope Technologies Corp. (Highlands Ranch, Colo.). The other is coming from a tiny, venture-capital-funded start-up in San Francisco called OQO Corp. [see photo above]. OQO's planned mini-tablet, which it bills as an ultrapersonal, is equipped with a1-GHz Crusoe processor, an electrostatic tablet screen, a 10-GB drive, and 256MB of RAM. It will provide for IEEE 802.11b wireless networking.

Antelope's Meta Pad prototype was developed under the direction of Ken Ocheltree at the IBM Thomas J. Watson Research Center (Yorktown Heights, N.Y.). With flexibility as their prime design objective, IBM researchers pulled all the I/O devices, the power supply, and the display out of the main handheld unit, leaving a mobile computing core just 7.5 by 4.5 by 1.9 cm.

The stand-alone core is the heart of the Meta Pad, and consists of an 800-MHz Transmeta Crusoe processor, a 10-GB hard drive, 256MB of memory, and a Silicon Motion Lynx 3-D graphics chipset. To make it a fully configured system, the power supply is hooked up and I/O accessories are added—tablet, keyboard, dock, and a goggles-like display, depending on the application. The last will likely be limited to military applications, one of the markets being targeted by Antelope. The company is gearing up to manufacture a batch of 10 000 units for its first commercial customers.

Mass-market pricing has yet to be set, but "we will definitely go consumer [in 2003]," says Antelope president Kenneth Geyer. "Even though we've been saying this is more for high-end industrial, the overwhelming response from the consumer area has caught us off guard."

Among the planned tablets, the tiniest so far—by a hair—would seem to be the one planned by OQO. At 6.5 by 4.5 by 2.5 cm, it is smaller than a Game Boy though still bigger than a Tamagotchi, the fad toy that children carry around on key rings. Perhaps that's a harbinger of the next generation of downsized devices: keychain PCs!

—Alexander Wolfe

PHOTOS: FUJITSU/OQO