Altered Beast was an arcade game made by SEGA for the System16 class of hardware.
Altered Beast was the packin game for the Sega Genesis in the North American market during the 1988 launch. It was to showcase that arcade games could be 'brought home'.
DATSU was able to clone the System16 board, including making their own version of the custom SEGA logic, to produce their own clone boards. Unlike the official SEGA board, the DATSU used 2 YM2203 Music chips.