DOS 4.5 File and Volume Disk Management SystemThis publication describes the process and the products that Walland Philip Vrbancic, Jr., an Electrical Engineer, an Aerospace Senior Systems Engineer, and a Professional Programmer since 1983, created when he designed and programmed another enhanced Disk Operating System (DOS) for his Apple ][+ and for his Apple e in order to manage Apple ][ Files and Volumes. Wherever he is able, Mr. Vrbancic has included source code samples, schematic diagrams,