scroll wheel like most mice, but the most common type is a “scroll ring” which is spun around the ball. Kensington's SlimBlade Trackball similarly tracks the ball itself in three dimensions for scrolling. and into the 2020s, two major companies produce consumer trackballs, Logitech and Kensington, although Logitech has narrowed its product line to two models. Other smaller companies occasionally offer a trackball in their product line. Microsoft produced popular models including The Microsoft Trackball Explorer, but has since discontinued all of its products. In September 2017 Logitech announced release of MX-Ergo Mouse, which was released after 6 years of its last trackball mouse. Special applications Large trackballs are sometimes seen on computerized special-purpose workstations, such as the radar consoles in an air-traffic control room or sonar equipment on a ship or submarine. Modern installations of such equipment may use mice instead, since most people now already know how to use one. However, military mobile anti-aircraft radars, commercial airliners (such as Airbus A380 and Airbus A350) and submarine sonars tend to continue using trackballs, since they can be made more durable and more fit for fast emergency use. Large and well made ones allow easier high precision work, for which reason they may still be used in these applications (where they are often called "tracker balls") and in computer-aided design. Trackballs have appeared in video games, particularly early arcade games (see a List of trackball arcade games). In March 1978, Sega released World Cup, an association football game with trackball controls. In October 1978, Atari released Atari Football, which popularized the use of a trackball, with the game's developers mentioning it was inspired by an earlier Japanese association football game. Other notable trackball games include Atari's Centipede and Missile Command – though Atari spelled it "trak-ball". Console trackballs, now fairly rare, were common in the early 1980s: the Atari 2600 and 5200 consoles, as well as the competing ColecoVision console, though using a joystick as their standard controller, each had one as an optional peripheral. The Apple Pippin, a console introduced in 1996, had a trackball built into its gamepad as standard. Trackballs were occasionally used in e-sports prior to the mainstreaming of optical mice in the early 2000s because they were more reliable than ball mice, but now they are extremely rare because optical mice offer superior speed and precision. Trackballs remain in use in pub golf machines (such