You got it! The roll is your negative. That was one of the advertised advantages of APS film - it was a very neat idea, that never really took off - film people were too accustomed to regular film, pros wanted the larger dimensions of film, and digital came along to put the nail in the coffin. I have an APS camera, Canon EOS-IX, that is a great camera...though it hardly ever gets used anymore since I went digital years ago. Still hang on to all the little developed rolls though, in case I ever wanted to make new prints or a CD.