Huskerdav

I am an old time game junkie. I have found working emu's for NES, SNES, and Genesis for PS1/PS2's. Does anyone know where I can find working emulators for the PS1 or PS2 for Atari systems, Intellivision and/or Colecovision??? I am dying to enjoy old time games like Combat, Yar's Revenge, Ladybug, etc... on my PS2... Thanks, Dave