mounted to a small cardboard box using duct tape. The glasses were never commercialized due to ghosting, but E&S was a very early adopter of third-party glasses such as the StereoGraphics CrystalEyes in the mid-1980s. Matsushita Electric (now Panasonic) developed a 3D television that employed active-shutter technology in the late 1970s. They unveiled the television in 1981, while at the same time adapting the technology for use with the first stereoscopic video game, Sega's arcade game SubRoc-3D (1982). In 1985 3D VHD players became available in Japan from manufacturers such as Victor (JVC), National (Panasonic), and Sharp. Other units were available for field sequential VHS tapes including the Realeyes 3D. A few kits were made available to watch field sequential DVDs. Sensio released their own format which was higher quality than the High Quality Field Sequential (HQFS) DVDs. Games The method of alternating frames can be used to render modern 3D games into true 3D, although a similar method involving alternate fields has been used to give a 3D illusion on consoles as old as the Master System and Family Computer. Special software or hardware is used generate two channels of images, offset from each other to create the stereoscopic effect. High frame rates (typically ~100fps) are required to produce seamless graphics, as the perceived frame rate will be half the actual rate (each eye sees only half the total number of frames). Again, LCD shutter glasses synchronized with the graphics chip complete the effect. In 1982, Sega's arcade video game SubRoc-3D came with a special 3D eyepiece, which was a viewer with spinning discs to alternate left and right images to the player's eye from a single monitor. The game's active shutter 3D system was jointly developed by Sega with Matsushita (now Panasonic). In 1984, Milton Bradley released the 3D Imager, a primitive form of active shutter glasses that used a motorized rotating disc with transparencies as physical shutters, for the Vectrex. Although bulky and crude, they used the same basic principle of rapidly alternating imagery that modern active shutter glasses still use. Nintendo released the Famicom 3D System for the Famicom in October 1987 in Japan, which was an LCD shutter headset, the first home video game electronic device to use LCD Active Shutter glasses. Sega released the SegaScope 3-D for the Master System Worldwide in November 1987. Only eight 3D compatible games were ever released. In 1993