On his most recent business flight, the traveler tucked several novels into his shirt pocket and, as a last-minute precaution against having the book go blank, tossed an extra battery into his flight bag.
One does not usually associate extra battery life with reading novels, but in the case of the Voyager Co.'s Expanded Books -- books designed to be read on an Apple Computer Macintosh Powerbook screen instead of on paper -- battery life becomes important.
It simply would not do to have the computer book lose power LTC just as the dinosaur's dripping jaws start to close around the hero's leg and. . . .
Books on a computer screen? At first blush, the idea seems absurd. The printed book is an ideal medium: small, lightweight, interactive, portable, rugged, inexpensive and readable without batteries.
The Powerbook, in contrast, is bulky, heavy, only modestly portable ("I can't imagine taking one into the bathroom," one avid reader in my family said), delicate, expensive and very needy when it comes to power.
Further, the quality of text on a computer screen is inferior to the printed page. The choices of reading material are extremely limited. The vertical page layout of conventional books is alien to the horizontal computer screen of the Powerbook.
The computer book cannot be read in the myriad positions possible with a book. (The other morning at the local health club, I saw a man reading a book while hanging upside down, bat-like, from a spine-stretching device. Try that with a Powerbook.)
And, perhaps most damning, the familiar tactile sense of holding a book and caressing its pages is lost when it is transferred to metal and plastic and glass and silicon.
Having noted all of these drawbacks, I remain convinced that computer-based books represent a profound and important alternative in the delivery of reading material.
The hardware needed to take full advantage of disk-based books is not advanced enough yet, but the promise is evident.
Voyager's Expanded Books consist of the complete text of a book, plus some modest "expansions" not found in the hardcover or paperback versions, all compressed onto a standard diskette and "glued together" with the Hypercard program.
The Apple Powerbook 170 is particularly well suited for these early books because it has a bright, active-matrix screen, better than the screen of most other notebook computers, and the ability to run Hypercard.
In the case of the Michael Crichton thriller "Jurassic Park," the expansions that give the Expanded Books their name include illustrations of the beasts, simple animated fractal graphics and some dinosaur sound effects.
But those tricks are pretty tame, as special effects go, and are limited by the computer's hardware.
The Macintosh has better built-in sound and graphics capabilities than most other computers, but the really exciting sounds and graphics will come when miniature optical disks replace the magnetic drives that are now standard.
CD-ROM optical drives have the capacity to store full-motion video and compact-disk-quality sound, but today's CD-ROM drives are too bulky and expensive for notebook computers.
Sony Corp. of Japan reportedly has a miniature optical disk in the final stages of development. When it is eventually incorporated into small, portable computers, one might be able to read "Jurassic Park," view film clips from the Steven Spielberg film and listen to the movie soundtrack.
Hardware alone is not the key to books on disk. Another element is the ability to manipulate the text and graphics.
Hypercard is a software engine that allows the user to forge links from one object to another within a book. There are similar systems on DOS and Windows computers, but none is a match $$ for Hypercard on the Macintosh.
Using Hypercard, one can point at the name of an obscure character in Chapter 10, using the Powerbook's built-in trackball pointing device, and jump immediately to an index of all references to that character. One can do the same thing in a printed book only by flipping back to the early chapters and searching page by page.
And because all the text is digital, it can be manipulated in the same ways as other computer documents.
Older readers, or those with impaired vision, might wish to increase the size of the text. Notes and other annotations can be typed in the margins of the pages.
Sections can be highlighted in bold or italic text. Electronic "bookmarks" can be inserted as often as needed.
In short, the reader can be more than a passive consumer of the book, and indeed can modify it to meet individual needs.
Because conventional books have bulk, it is at first disconcerting to think of several novels packed onto one small diskette. Several of Voyager's books are compressed onto the disk and expanded later, on the computer's hard disk drive.
Actually, it does not take much compression to get a standard book onto a diskette.
At approximately two kilobytes a page, a 350-page book leaves lots of blank space on the Powerbook's high-density, 1.2-megabyte diskettes. (There are 1,048 kilobytes in a megabyte.) The leftover space can be used for another book or for sound effects and fancy animated graphics.
Voyager is believed to be the only company currently publishing books on diskette for portable computers.
Nine fiction and non-fiction books are available now, including "Jurassic Park," "A Hitch Hiker's Guide to the Galaxy," "Zen and the Art of Motorcycle Maintenance," "The Annotated Alice," "Brave New World," and "Backlash."
Each book has a suggested list price of $19.95. (The computer costs a few thousand dollars extra.)
In coming months, Voyager plans to release Gloria Steinem's "Revolution From Within," William Gibson's technopunk classic "Neuromancer" trilogy, and the first volume of the complete works of the late Isaac Asimov.
After that, according to Robert Stein of Voyager, the company plans to release an average of three titles a month.
Before too long a complete library of computer-based books is expected from many different publishers. Random House recently told of plans to publish Modern Library classics on diskette, for use on the Powerbooks.
The real breakthrough in computer-based books will come when authors write with digital presentation in mind, harnessing the so-called multimedia powers of sound, graphics, animation and perhaps video.
In the end, it is highly unlikely that digital books will replace printed books.
After all, the power of the human imagination to envision scenes and make mental associations is still far more powerful than any computer graphics or Hypercard links.
But just as motion pictures, videocassettes, audio CD's and laser disks added to the media of expression, so too will disk-based books.