earlier hard drives used in the pc, such as mfm and rll drives, divided each cylinder into an equal number of sectors, so the chs values matched the physical properties of the drive. a drive with a chs tuple of codice_43 would have 500 tracks per side on each platter, two platters (4 heads), and 32 sectors per track, with a total of 32 768 000 bytes (31.25 mb).