Here is a set of photoshop brushes (made w/ CS3) I put together for creating classic/retro (old school) dungeon maps:
http://jphazen.deviantart.com/#/d4oo7lw
feel free to download and use, credit not required but appriciated.
This is the first set of brushes I've made like this and I will try to expand it as time permits.
Enjoy
