Sega Mark III, a home video game console released by Sega Enterprises (now Sega) on October 20, 1985. It was developed as a successor to the SG-1000 and SG-1000II. It is equipped with a Z80A CPU. As software media, it supports two types: "My Card," an IC card-type ROM, and ROM cartridges. It was sold as the "Sega Master System" outside of Japan, and was particularly successful in Europe and South America. The power supply is DC9V, and an AC adapter was included with the main unit. All the included accessories are shown in the photo. Operation has not been confirmed. Due to being an old game console manufactured in the Showa era, approximately 40 years ago, it is being sold as junk. It has been stored in a closet for many years. There are scratches and stains due to aging.