Tandem Computers
https://ja.wikipedia.org/wiki/%E3%82%BF%E3%83%B3%E3%83%87%E3%83%A0%E3%82%B3%E3%83%B3%E3%83%94%E3%83%A5%E3%83%BC%E3%82%BF%E3%83%BC%E3%82%BA