The Testbed Devices of the Infrastructure for Ubiquitous Computing Project


The project constructed the three prototype devices. The Pad and Tab were funded partially by ARPA; the Board, the first project to be completed, was not. All prototypes were fully functional and in everyday use by PARC experimenters.



The Pad was a prototype pen computer. It was 9x11x1", had a four 4 hour battery life, and weighed 5 pounds. It used a Motorola 683xx processor with 4 MB ram running a unique real-time operating system. The Pad featured a PCMCIA slot, an electronic pen of our own design with a built-in microphone, a 640x480 4 level display, keyboard and serial ports. The Pad could communicate through infrared at 19.2kbs, through a unique nearfield radio at 240kbs, and through a 1Mbs tether which also supplied external power for operation and recharging. A complete Pad system also had a radio basestation that served as a recharging station and Ethernet gateway for the Pads.
The Tab was a prototype handheld computer. It was 2x3x0.5", had a 2 week battery life on rechargeable batteries, and weighed 7 oz. It used a Phillips 8051 processor with 128k NVRAM. It featured an external I2C external bus, a custom resistive touch screen, and a 128x64 mono display. A complete Tab system included an infrared basestation in the ceiling for LAN connectivity. The Tab project is consider by many to be the most significant of the three prototyping efforts.


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Mark Weiser, 03/17/96 7:03:56 PM