On File is an ideal application for the [[ROMDOS]] D20 80 track disks, which can store up to 256 records files in a single directory user (tested and working using On File2025) as well as the . The 20 MB [[Dobbertin Harddisc]] or similar media which supports support up to 512 directory entriescan also be used. The amount of data that can be stored and accessed using On File and On File Register is huge for the CP/M-80 world.