For you newer members who are not aware of it the ACWGC has a website that provides a wealth of information on the HPS game system files. Specifically how the pdt and oob files are set up and how the pdt can be modified as well as a primer to get you started with the Scenario Editor. You can browse the information at
http://home.comcast.net/~acwco_engineering/For the older members Robert Frost, of the Norris-Frost Team that created the Battleground game mods so many of us tried, has released what I think is an exhaustive study of the HPS system as well as several pdt files he has created that look like they might provide a more historical flavor to the system. He has provided the information for posting at the Engineering site and it has recently been added.