OK, 90-25 i hear often, I would think that someone has a list for the 90 codes. What area do you live in? I'm up by Byron so there is not too much to monitor, but I have some stuff in there for the county, the power plant and such. I moved back to this area after being gone for 6 years so a lot has changed. I'm trying to get some starcom21 stuff programed, there is a site in oregon, il but it doesnt seem to be active. As for the MDT's, you know some of the older ones can be decoded with a scanner and a computer. I'm not sure if anyone in this area uses the older versions.
Scott