Atari 810

The Atari 810 was a floppy disk drive for the Atari 400 and 800 computers, using a 5 1/4" disk format consisting of 720 sectors (numbered from 1 to 720 decimal, or 1 to 2D0 hex) each containing 128 bytes (numbered from 0 to 127 decimal, or 0 to 7F hex).

The contents of the disk were organized using the Atari File Management Subsystem (FMS) as the filesystem. This allocated sector 360 (168 hex) for the VTOC (Volume Table of Contents) and sectors 361-368 (169-170 hex) for the directory. Sector 720 (2D0 hex) was unused, and bootable disks had the boot record in sector 1 (followed by a DOS.SYS file in the next few sectors), leaving the remaining sectors free for user files.