Understanding the Atari DOS 2 File Format

90K per disk

In ANALOG Computing Issue 8, Tony Messina writes about the DOS disk format in his Utility column. In this column he discusses the DOS disk format, focusing on the data, directory and boot sectors.

I loved reading about this again to refresh my memory on how this all worked. Atari single-sided disks held just 90K. There were 720 sectors, each 128 bytes in…