I have a few older files saved as Cricket Graph III files on my Mavericks Mac. I put Sheep Shaver/OS 9 on the computer and it's running fine. I was even able to get Cricket Graph installed. However, somehow the files have lost their identity so I cannot get Cricket Graph to open them. I recall there was a method to assign a 4 letter code to files that identified them as belonging to certain programs, but I have been unable to find those details. So, any of you other old-timers recall how to do this? Thanks!