Yes, the process for making a floppy useful to an OS is the same as any other computer media.
The common "1.44" MB floppy is actually 2.0 MB (12 Mbits) worth of data. However, a controller chip (usually an NEC 765 or equivalent) is used to write certain patterns onto the diskette; for a standard 3.5" 1.44 floppy, the 'formatter' writes 18 sectors per track, each sector is 512 bytes. http://www.bitsavers.org/components/nec/_dataSheets/uPD765_App_Note_Mar79.pdf These 'sectors' have extra info that the disk controller chip uses to figure out where the actual data is; that is, each of those 18 sectors has some info for synchronization, and also has the Sector Number. Even though there is an 'index' pulse once per revolution that tells you where to start looking for data, the controller chip scans the magnetic domains/transitions (encoded as Modified FM, aka MFM) and finds the proper sector it was commanded to. It then proceeds to read / write the data as commanded on that sector. The low-level format leaves the diskette with 18 sectors per track, and there are a total of 80 tracks; there are also 2 read/write heads, one on each side, so there are 36 tracks per 'cylinder' (a cylinder holds all the sectors can can be read/written without moving the disk drive head). 36 sectors per cylinder x 80 cylinders = 2,880 sectors Times 512 bytes per sector = 1,474,560 (formatted) bytes. But yes, you're right, when you do *# newfs_msdos -f 1440 /dev/rsd1a* you get an MS-DOS filesystem, which is described here: https://www.eit.lth.se/fileadmin/eit/courses/eitn50/Literature/fat12_description.pdf And yes, sectors 0 through 32 are used up by the Filesystem (FAT1, FAT2, and Root Dir); that means there are only 2880 - 33 = 2,847 sectors (1,457,664 bytes) available for actual user data. And, yes, one consequence is that since there are an odd # of sectors available for user data, it is not possible to have 2 *identical* files that completely fills up a diskette -- thanks for spotting my error on this