I'm not one for using tools (except those that I make but even then hex editor is still king) but the SH5 guys needed something for quick editing/comparing/adding of the SDL file so I wrote an app for them. Since the file structure of the SDL file is unchanged from SH3 I can make it available to you all in SH4 also. In order to avoid having to update 3 different threads about this (SH5/4/3) I'm just going to give the link to the SH5 thread here:
http://www.subsim.com/radioroom/show...96&postcount=1