User blog comment:Boxtropica/The PTC filetype is rather cryptic, isn't it?/@comment-13254338-20140707002123

Those random symbols are 48 byte long strings of text called 'headers'. They basically hold information for PTC to read, like the program's name or what type of file it is (CHR, PRG, that sort of thing). Also, I think the extra "\00" at the end tells PTC to capitalize all of the commands, as evidenced by the fact that opening files where they aren't capitalized makes the commands capitalized. You should check out Randommouscrap's tutorial on the GRP File format. It will help you get to understanding headers of PTC files, as the headers are the same for all file types. Also, two things - 1) get a hex editor and 2) They make me feel incompetent as well, you're not alone :P