During the last 15 years, the dominant personal computing metaphor has shifted from the command line of UNIX and DOS to the desktop of Xerox PARC and the Apple Macintosh, a shift made necessary by the growing number of people who were using computers without becoming computer hobbyists (or, "hackers").

The desktop metaphor is a useful one for office work -- its notions of hierarchical storage, "file folders," and "trash cans" are second nature to most of the people using computers for routine memo writing and inventory work.

For active reading purposes, however, the desktop metaphor fails. Creative people rarely keep neat filing cabinets and rarely think in rigidly hierarchical terms. The joy in creativity comes from seeing unexpected links between seemingly disparate objects, and in forming new mental patterns from such links. Something different is needed.

The limits of the desktop metaphor affect commerce as well as art. Business practices in the new century will demand something more of professionals and their computers; something that the desktop metaphor will be incapable of fully assisting. What the creative workers of tomorrow need from their computers is assistance in integrating knowledge rather than filing it.

The central metaphor of the Lap Pilot has been designed to meet these needs.

When a Lap Pilot owner turns on his machine, what he sees is not a desktop but a simulated piece of paper on his 8.5" by 11" screen. This piece of paper (which, with scrolling, can actually be as long as the user wants to make it) is similar to a person's home page or bookmark file for the World Wide Web -- it lists the main categories of the users' interests, as well as whatever else the user wants to see immediately (perhaps the news of the day). Using the Lap Pilot stylus on the touch screen, the user can easily "flip" from this central page to his subsidiary pages.

The subsidiary pages generally fall into one of three categories:

• Subsidiary central pages -- Similar to the main central page, but limited to one particular topic.
• Texts -- Digital library documents such as books and magazine or newspaper articles. Can be viewed with or without user annotations.
• Annotations -- The user's comments on the texts, which can only be viewed with the accompanying text. Handwriting recognition software is used to index the annotations and allow for linking, but the visible annotations are saved and displayed as a graphical layer atop the text.

As we can infer from the types of subsidiary pages, the Lap Pilot can be used in two ways: linear or non-linear (or, to use the page metaphor, "reading" or "skimming"). In linear/reading mode, the user has a text, which he reads through and annotates. In non-linear/skimming mode, the user has a central page to which he accretes related links and ideas culled from the texts and noted in the annotations.

The function keys on the Lap Pilot's main unit work differently depending on which mode the machine is in. In linear mode, the two sets of keys are used to scroll from page to page or chapter to chapter (users can decide whether they want their machine to continuously scroll or to "flip" the page). In non-linear mode, the lower set of keys is used to scroll within a page, while the upper set is used as "forward" or "back" command keys.

Forming hypertext links with the Lap Pilot is a snap. Simply toggle on the split screen option for the main unit, load a text into each screen, and highlight the phrases to be linked.

The optional module is designed to provide high-quality images to accompany the text of the main unit. Rather than a touch-screen, the optional module has a 13" color, high-resolution, flat-screen display that is ideal for showing pictures and illustrations of all kinds. Optional video and sound cards can add extra functionality to the module.