"Built-in games," like those from the first generation, saw limited use during this era. Though the first generation Magnavox Odyssey had put games on cartridge-like circuit cards, the games had limited functionality and required TV screen overlays and other accessories to be fully functional. More advanced cartridges, which contained the entire game experience, were developed for the Fairchild Channel F, and most video game systems adopted similar technology. The first system of the generation and some others, such as the RCA Studio II, still came with built-in games while also having the capability of utilizing cartridges. The popularity of game cartridges grew after the release of the Atari 2600. From the late 1970s to the mid-1990s, most home video game systems used cartridges until the technology was replaced by optical discs. The Fairchild Channel F was also the first console to use a microprocessor, which was the driving technology that allowed the consoles to use cartridges. Other technology such as screen resolution, color graphics, audio, and AI simulation was also improved during this era. The generation also saw the first handheld game cartridge system, the Microvision, which was released by toy company Milton Bradley in 1979.