From Sega Retro
For decades Sega has been involved in many facets of the amusement arcade industry, including change machines (known as ryougae-ki (両替機) in Japan); systems in which a larger unit of currency (usually paper money) is exchanged for coins, which can then be used in arcade games. The concept is almost as old as the games are themselves.
Sega has been producing change machines for the Japanese market since at least the 1970s. The full extent of the range is unknown, and very little has been documented. Furthermore, venues may have chosen to customise units to better suit their needs, leading to further variations.
The following lists all known change machines released by Sega, in a rough chronological order:
New DP series
Medal change machines
In venues where real currency is not accepted, Sega has sold equipment which can dispense "medals" (tokens) - currency that can only be used in the current venue and has no monetary value.