填空题

Around the World in Eight Megabytes
When Microsoft put the original Flight Simulator program onto the market, in the early 1980s, I tried it for a while and then gave up. I had thought it would be fun to "take off" from Meigs Field, the airport on the Chicago lakefront where the simulator was programmed to start, and fly between the skyscrapers of the city toward whatever destination I chose. But the on- screen scenery turned out to be sketchy and uninteresting. Worse, I had no idea how to "land" the plane, at Meigs or anywhere else, and the program was not much help in teaching me. After ten or twenty flights that ended mainly with nosedives into the lake or countryside, I decided I could have more fun in other ways.
A dozen years later I became interested in learning to fly (and land) real airplanes, and I thought I should look at simulators again. There were now a range of programs, which were much more effective in teaching flying skills--or at least certain skills. They had also become a form of entertainment and virtual adventure captivating enough to attract vast numbers of users worldwide. According to Guinness World Records 2001, Microsoft’s Flight Simulator had sold a total of 21 million copies by June of 1999.
Simulators’ success is certainly deserved. Not many people fly real airplanes; fewer than 650,000 Americans are licensed pilots. But a larger group probably would like to fly. And even people who have almost no interest in flying (surely everybody finds it a little bit exciting to pretend to zoom through the air) or who view computer games as inherently creepy would find it hard to ignore the best modem versions. On a big, high-resolution computer screen you can find yourself facing all amazingly exact rendition of a Learjet cockpit, flying low over the Grand Canyon at dawn, with flashes of lightning visible in the distance, as you listen to air-traffic controllers direct you to the Flagstaff airport. You can take off in a pontoon plane from a lagoon in Bali, fly over paddies on the terraced hillsides, and then head toward java’s volcanic craters. You can approach Ayers Rock, in the center of Australia, and watch shadows move across it as the sun goes down. You can indulge in much of the visual romance of flying, without the time, expense, and training required to pilot a real plane.
These riveting effects are the result of an intriguing de facto division of labor. The programs themselves are ail commercial products, from Microsoft and a number of small firms. But a wide variety of add-ons and improvements come from tens of thousands of hobbyists around the world, who spend countless hours polishing or improving some aspect of a program--and then post their work on the Internet for others to share. The flight-sim culture is a delightful reminder of a long-forgotten era, somewhere back in the 1990s, when people were excited about creating software for the new things it would let them do, not simply as a means of gaining market share.
The flight-sim market resembles the rest of the software business mainly in that the most popular offering is from Microsoft. The current version of Microsoft’s program is Flight Simulator 2000, or FS2000, which computer discounters offer for about $50. (A "professional" version costs about $70. It includes more simulated airplanes and a larger number of places whose scenery is presented in extra-realistic detail.) With FS2000 and most other programs you can "fly" from practically any point on earth to any other; the differences among the programs lie mostly in the degree of scenic detail, plus certain aspects of the airplanes’ look and performance. With all these programs you can also specify the weather conditions through which you’ll pass on any particular trip: clouds, wind, turbulence, rain. The fanciest programs let you download the real-time weather for your route, from aviation sites on the Internet. Then you can see what it would be like to pilot a plane from Buffalo to Detroit through the blustery night weather occurring just now. As with other Microsoft products, FS2000’s strengths are related to its role as the industry standard. More hobbyists develop new airplanes or bits of scenery for this program than for the others. Its main shortcoming is its slow "frame rate" , which can result in a jerky on-screen image if the program is run on what is now considered a slow computer or one without an up-to-date video-display card.
Although in many software categories Microsoft’s product has become dominant, in flight sims there are still lively alternatives. The main ones are Flight Unlimited (FU3), by Electronic Arts; Fly! 2K, by Gathering of Developers; Pro Pilot 99, abandoned by its previous owner, Sierra Software, but being revived by ETC Interactive; and X-Plane, developed and sold by one Austin Meyer, of Columbia, South Carolina. Each of these programs has not only dedicated users, but also a reserve army of hobbyists creating enhancements and add-ons. Devotees discuss the programs on the main flight-sim Web sites, which included avsim, com and flightsim, com, and the Internet newsgroup.
The good parts of all the programs keep getiing better, because of those hobbyists and their burgeoning offerings on the major Web sites. Thousands of scenery supplements are available free for FS2000, and hundreds for the other programs. The big step toward dramatically more- realistic-looking scenery came when FS2000 was released, in the fall of 1999. Previous versions of the program had presented the world basically as a flat surface, onto which polygons representing mountains were plunked down. FS2000 introduced a far more accurate "terrain mesh" system. Real-word data from satellites and geodetic surveys are mapped onto a topographic model of the earth’s surface, with each square kilometer rendered at its actual average elevation. The "software developer kit" that Microsoft offers free with FS2000 allows hobbyists to apply the same approach and create much-finer detail using smaller geographic increments.
Other add-ons, most of which are free, let you fly different kinds of planes--the Spirit of St. Louis, Air Force One, the space shuttle. Hobbyists, largely in Europe, have created virtual airlines, with whole fleets of imaginary Airbuses and DC-10s that fly on schedule from London to Berlin and from Amsterdam to New York’s JFK. I have visited a Web site run by a virtual air traffic controller. Flight-sim users around the world send him their flight plans--say, Los Angeles to San Francisco, departing at noon. He tells them when they’re cleared for takeoff and follows their route by way of Internet messages. A large number of add-on planes are exquisitely detailed representations of Boeing747s or 777s, with all the dials and controls in working order. With a good computer monitor, the right scenery add-ons, and the joystick and pedals, you can feel like an airline captain instead of one of the passengers habitually grousing in the back of the plane.
The exhilarating part of flight sims is taking off in a certain direction and seeing what wonders unfold beneath you. This, to me, is the engrossing part of real flying, too. You head east out of Seattle, and soon enough there’s Idaho, and the open range of Montana, and the beginning of the Midwest. Everyone understands the concept of how the states fit together, but seeing them in one continuous band, from an altitude low enough to make out individual farmhouses clustered in the prairie, yet high enough to see the way rivers and ridgelines snake around communities, is very different from looking at a map. And to take off from Charles de Gaulle, circle the monuments of Paris, and then head north until the cliffs of Dover come into view is something I don’t expect ever to do in a real airplane. The cliffs looked beautiful, just a moment ago, on my computer screen. The exciting part of both Flight Simulator and real flying is ______.