What is a good source for Silver's proof (or a more modern version) that Con($\exists \omega_1$-Erdos cardinal) implies Con(Chang's Conjecture)?

Silver's original proof seems to have never been published and I didn't find a proof in the set theory books I looked at (i.e. Jech's "Set Theory: the 3rd Millennium Edition" and Kanamori's "Higher Infinite")