» Thu Nov 15, 2012 4:30 pm
Just download a source port that supports Multiplayer and point it to the Doom 1 and Doom 2 IWAD files. I recommend Skulltag/Zandronum personally.
Unless for some reason those IWAD files are altered to prevent use with user-made sourceports, which would be a really really really stupid move. I doubt it, more than likely there is multiplayer on the console versions because that is done through a console specific sourceport that supports multiplayer, no change necessary for the IWADs.