  We compute the equation of state of isospin asymmetric QCD at zero and
non-zero temperatures using direct simulations of lattice QCD with three
dynamical flavors at physical quark masses. In addition to the pressure and the
trace anomaly and their behavior towards the continuum limit, we will
particularly discuss the extraction of the speed of sound. Furthermore, we
discuss first steps towards the extension of the EoS to small non-zero baryon
chemical potentials via Taylor expansion.
