The Casio H-801 Biolator is an arithmetic calculator with 8 digits precision and algebraic logic. It has 6 functions, 20 keys and a VFD (vacuum fluorescent) display. The power source is 2xAA batteries. The calculator was manufactured in Japan.
One of the many fads in the 1970s was Biorhythms. Like most successful pseudoscientific theories, the notion of biorhythms has a basis in scientific fact, to the extent that many biological processes are cyclic. But the notion that a set of phased monthly cycles starting from the moment of birth and continuing through a lifetime, unperturbed by any trauma, has more in common with astrology and numerology than any kind of understanding of the human body or mind.