American video game companies were increasingly licensing products from Japanese companies, who in turn were opening up North American branches. By 1982–1983, Japanese manufacturers had more directly captured a large share of the North American arcade market, which Gene Lipkin of Data East USA partly attributed to Japanese companies having more finances to invest in new ideas. Technology Arcades catering to video games began to gain momentum in the late 1970s, with Space Invaders (1978) followed by games such as Asteroids (1979) and Galaxian (1979). Arcades became more widespread in 1980 with Pac-Man, Missile Command and Berzerk, and in 1981 with Defender, Donkey Kong, Frogger and others. The central processing unit (CPU) microprocessors in these games allowed for more complexity than earlier transistor-transistor logic (TTL) discrete circuitry games such as Atari's Pong (1972). The arcade boom that began in the late 1970s is credited with establishing the basic techniques of interactive entertainment and for driving down hardware prices to the extent of allowing the personal computer (PC) to become a technological and economic reality. While color monitors had been used by several racing video games before (such as Indy 800 and Speed Race Twin), it was during this period that RGB color graphics became widespread, following the release of Galaxian in 1979. Galaxian introduced a tile-based video game graphics system, which reduced processing and memory requirements by up to 64 times compared to the previous framebuffer system used by Space Invaders. This allowed Galaxian to render multi-color sprites, which were animated atop a scrolling starfield backdrop, providing the basis for the hardware developed by Nintendo for arcade games such as Radar Scope (1980) and Donkey Kong followed by the Nintendo Entertainment System console. The Golden Age also saw developers experimenting with vector displays, which produced crisp lines that couldn't be duplicated by raster displays. A few of these vector games became great hits, such as 1979's Asteroids, 1980's Battlezone and Tempest and 1983's Star Wars from Atari. However, vector technology fell out of favor with arcade game companies due to the high cost of repairing vector displays. Several developers at the time were also experimenting with pseudo-3D and stereoscopic 3D using 2D sprites on raster displays. In 1979, Nintendo's Radar Scope introduced a three-dimensional third-person perspective to the shoot 'em up genre, later imitated by shooters such as Konami's Juno First and Activision's Beamrider in 1983. In 1981, Sega's Turbo