The disk image is just a simple GRiD MS-DOS 5.0 boot disk. It doesn't have anything on it other than the minimum system files needed to boot MS-DOS. I am, however, including all of the files from the GRiD MS-DOS 5.0 installation on my 1550. I'm not sure what's supposed to be there so I just copied it all. With everything there, it should hopefully allow for the creation of a proper disk(s).