games, light guns for shooting games, and musical instrument controllers for rhythm games. Some newer consoles also include optional support for mouse and keyboard devices. A controller may be attached through a wired connection onto the console itself, or in some unique cases like the Famicom hardwired to the console, or with a wireless connection. Controllers require power, either provided by the console via the wired connection, or from batteries or a rechargeable battery pack for wireless connections. Controllers are nominally built into a handheld unit, though some newer ones allow for separate wireless controllers to also be used. Game media While the first game consoles were dedicated game systems, with the games programmed into the console's hardware, the Fairchild Channel F introduced the ability to store games in a form separate from the console's internal circuitry, thus allowing the consumer to purchase new games to play on the system. Since the Channel F, nearly all game consoles have featured the ability to purchase and swap games through some form, through those forms have changes with improvements in technology. ROM cartridge or game cartridge The Read-only Memory (ROM) cartridge was introduced with the Fairchild Channel F. A ROM cartridge consist of a printed circuit board (PCB) housed inside of a plastic casing, with a connector allowing the device to interface with the console. The circuit board can contain a wide variety of components, at the minimum, the read-only memory with the software written on it. Later cartridges were able to introduce additional components onto the circuit board like coprocessors, such as Nintendo's SuperFX chip, to enhance the performance of the console. Some consoles such as the Turbografx-16 used a smart card-like technology to flatten the cartridge to a credit-card-sized system, which helped to reduce production costs, but limited additional features that could be included onto the circuitry. PCB-based cartridges waned with the introduction of optical media during the fifth generation of consoles. More recently, ROM cartridges have been based on high memory density, low cost flash memory, which allows for easier mass production of games. Sony used this approach for the PlayStation Vita, and Nintendo continues to use ROM cartridges for its 3DS and Switch products. Optical media Optical media, such as CD-ROM, DVD, and Blu-ray, became the primary format for retail distribution with the fifth generation. The CD-ROM format had gained popularity in the 1990s, in the midst of