  We give a numerical simulation of the generation of the magnetic field and
the charge-separation signal due to the chiral magnetic effect (CME) --- the
induction of an electric current by the magnetic field in a parity-odd matter
--- in the collisions of isobaric nuclei, $^{96}_{44}$Ru + $^{96}_{44}$Ru and
$^{96}_{40}$Zr + $^{96}_{40}$Zr, at $\sqrt{s_{\rm NN}}=200$ GeV. We show that
such collisions provide an ideal tool to disentangle the CME signal from the
possible elliptic-flow driven background effects. We also discuss some other
effects that can be tested by using the isobaric collisions.
