Complex sentence: During the 1980s it worked mainly as a subcontractor for Sega and its arcade division, and the company was renamed Coreland in 1982, It has been partially owned by Bandai since 1989, when it gained its current name.
Split into simpler sentences: During the 1980s it worked mainly as a subcontractor for Sega and its arcade division, and the company was renamed Coreland in 1982. It started to be partially owned by Bandai in 1989, when it gained its current name.