in 1981 was Microsoft Adventure, which IBM described as bringing "players into a fantasy world of caves and treasures". BYTE that year stated that the computer's speed and sophistication made it "an excellent gaming device", and IBM and others sold games like Microsoft Flight Simulator. The PC's CGA graphics and speaker sound were poor, however, and most customers bought the powerful but expensive computer for business. One ComputerLand owner estimated in 1983 that a quarter of corporate executives with computers "have a game hidden somewhere in their drawers", and InfoWorld in 1984 reported that "in offices all over America (more than anyone realizes) executives and managers are playing games on their computers", but software companies found selling games for the PC difficult; an observer said that year that Flight Simulator had sold hundreds of thousands of copies because customers with corporate PCs could claim that it was a "simulation". From mid-1985, however, what Compute! described as a "wave" of inexpensive IBM PC clones from American and Asian companies, such as the Tandy 1000, caused prices to decline; by the end of 1986, the equivalent to a $1600 real IBM PC with 256K RAM and two disk drives cost as little as $600, lower than the price of the Apple IIc. Consumers began purchasing DOS computers for the home in large numbers. While often purchased to do work on evenings and weekends, clones' popularity caused consumer-software companies to increase the number of IBM-compatible products, including those developed specifically for the PC as opposed to porting from other computers. Bing Gordon of Electronic Arts reported that customers used computers for games more than one fifth of the time whether purchased for work or a hobby, with many who purchased computers for other reasons finding PC games "a pretty satisfying experience". By 1987, the PC market was growing so quickly that the formerly business-only computer had become the largest and fastest-growing, and most important platform for computer game companies. DOS computers dominated the home, supplanting Commodore and Apple. More than a third of games sold in North America were for the PC, twice as many as those for the Apple II and even outselling those for the Commodore 64. With the EGA video card, an inexpensive clone had better graphics and more memory for games than the Commodore or Apple, and the Tandy 1000's enhanced graphics, sound, and built-in joystick ports made it