Per the OP comment above, this was Firebird by Charles L. Harness, published 1980 or 1981 (isfdb and goodreads disagree).
Summary from the Amazon Kindle entry:
From the distant dipoles of the universe, two telepathic computers, Largo and Czandra, known as Control, rule over life on all civilized planets. And now, with Project Cancelar, Control has formulated a plan for achieving immortality...a plan which requires as fodder the collapsing of the universe and the destruction of all life. And there is nothing the humans can do.
But there is another force in the universe, hidden in the abyss of the Silent Quarter...plotting destruction of Control. A force that is about to be demolished! Before it expires, it launches from its depths a magic ring, an elixir, and a man and a woman in love - riding within the living spirit of a remarkable spaceship to do battle against the cumulative technology of the entire universe.