Tablet PC opens up computing options

Straddling the new and old in mobile computing-and hedging its bets on evolving tastes-the HP/Compaq TC1000 morphs from tablet to notebook and desktop PC in the guise of a fairly lightweight, high-performance portable.

Mechanical-design technology drives much of the hardware innovation. The central slate with display, touchscreen, electronics and storage can dock in, or disconnect from, a separate keyboard assembly. When the two units are connected, a sleek but complex swivel hinge lets them be used notebook-style or folded back on themselves for tablet mode. The keyboard can be removed for maximum portability, and desktop use is also possible with separate input and display peripherals.

That flexibility comes at the price of some awkwardness in balance. Despite steps to center the tablet docking point on the keyboard base, most of the TC1000's weight is supported above base height-the reverse of a conventional notebook PC and a potential source of instability.

The touchscreen has an intriguing noncontact pointing scheme from Fine Point Innovations. The active-pen digitizer radios information about the pen's location to a sensor grid behind the LCD, pegging its position with surprising accuracy. For durability, a tempered-glass cover forms the tablet surface, adding stiffness to the TC1000 along with a notable 5.3 ounces in weight-more than the 4.6 ounces of LCD panel and pen receiver board combined.

Low-power processor technology is central to the design. HP/Compaq chose Transmeta's TM-5800 CPU, presumably for its claimed energy efficiencies. Although CPU power savings are diluted by other power-hungry devices such as LCD, hard drive and peripheral electronics in the end system, consumed power is held to less than 20 watts in most use cases. The PCI slot with 802.11b card, Ethernet and USB interfaces is managed by controllers from Texas Instruments, Intel and NEC respectively-all three residing on the internal PCI bus. A Via Technologies I/O manages other peripherals' gateway to the system. System audio is also managed through the Via chip, which connects to sound devices from Analog Devices and TI.

Estimated cost of goods sold was well under half the $1,799 base retail price-expensive compared with notebooks with similar performance. Price premiums are part of the uphill battle facing Tablet PCs, whose features otherwise make for a potentially important product category.

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