This replacement for CP/M's Basic Disk Operating System (BDOS) provides two new function calls designed to allow programs which copy and modify files to easily preserve file date and time stamps while remaining downward compatible with CP/M. Also features automatic disk login, archiving, and public files. See CONTENTS.Z8D for short descriptions of all files. Source code, installation and programming notes, and useful utilities are included. October 1, 1987 by Carson Wilson.