Commander X16

This reads the disk directory in BASIC. This is a super simple example and doesn't actually parse the files... it's just smart enough to read "$" and print it to the screen. 

This version is smarter. The directory is actually read as a BASIC file. Each line has a 2 byte link address, 2 byte line number, a variable length text string, and a null. 

So this program reads and discards the link address, reads a 16-bit number for the file size, then reads until the null to get the filename and filetype.