| Name | Type | Description | 
| ty | str | Type of disk (e.g. removable, winchester) | 
| dt | str | Type of controller (e.g. SMD, ESDI, floppy) | 
| ns | num | Number of sectors per track | 
| nt | num | Number of tracks per cylinder | 
| nc | num | Total number of cylinders on the disk | 
| sc | num | Number of sectors per cylinder, ns*nt default | 
| su | num | Number of sectors per unit, sc*nc default | 
| se | num | Sector size in bytes, DEV_BSIZE default | 
| sf | bool | Controller supports bad144-style bad sector forwarding | 
| rm | num | Rotation speed, rpm, 3600 default | 
| sk | num | Sector skew per track, default 0 | 
| cs | num | Sector skew per cylinder, default 0 | 
| hs | num | Headswitch time, usec, default 0 | 
| ts | num | One-cylinder seek time, usec, default 0 | 
| il | num | Sector interleave (n:1), 1 default | 
| d[0-4] | num | Drive-type-dependent parameters | 
| bs | num | Boot block size, default BBSIZE | 
| sb | num | Superblock size, default SBSIZE | 
| ba | num | Block size for partition `a' (bytes) | 
| bd | num | Block size for partition `d' (bytes) | 
| be | num | Block size for partition `e' (bytes) | 
| bf | num | Block size for partition `f' (bytes) | 
| bg | num | Block size for partition `g' (bytes) | 
| bh | num | Block size for partition `h' (bytes) | 
| fa | num | Fragment size for partition `a' (bytes) | 
| fd | num | Fragment size for partition `d' (bytes) | 
| fe | num | Fragment size for partition `e' (bytes) | 
| ff | num | Fragment size for partition `f' (bytes) | 
| fg | num | Fragment size for partition `g' (bytes) | 
| fh | num | Fragment size for partition `h' (bytes) | 
| oa | num | Offset of partition `a' in sectors | 
| ob | num | Offset of partition `b' in sectors | 
| oc | num | Offset of partition `c' in sectors | 
| od | num | Offset of partition `d' in sectors | 
| oe | num | Offset of partition `e' in sectors | 
| of | num | Offset of partition `f' in sectors | 
| og | num | Offset of partition `g' in sectors | 
| oh | num | Offset of partition `h' in sectors | 
| pa | num | Size of partition `a' in sectors | 
| pb | num | Size of partition `b' in sectors | 
| pc | num | Size of partition `c' in sectors | 
| pd | num | Size of partition `d' in sectors | 
| pe | num | Size of partition `e' in sectors | 
| pf | num | Size of partition `f' in sectors | 
| pg | num | Size of partition `g' in sectors | 
| ph | num | Size of partition `h' in sectors | 
| ta | str | Partition type of partition `a' (4.2BSD filesystem, swap, etc) | 
| tb | str | Partition type of partition `b' | 
| tc | str | Partition type of partition `c' | 
| td | str | Partition type of partition `d' | 
| te | str | Partition type of partition `e' | 
| tf | str | Partition type of partition `f' | 
| tg | str | Partition type of partition `g' | 
| th | str | Partition type of partition `h' |