The
hp driver is a generic MASSBUS disk driver which handles the standard DEC controllers. It is typical of a block-device disk driver; block I/O is described in
physio(4).
The script
MAKEDEV(8) should be used to create the special files; if a special file needs to be created by hand consult
mknod(8). It is recommended as a security precaution to not create special files for devices which may never be installed.
The first sector of each disk contains both a first-stage bootstrap program and a disk label containing geometry information and partition layouts (see
disklabel(5). This sector is normally write-protected, and disk-to-disk copies should avoid copying this sector. The label may be updated with
disklabel(8), which can also be used to write-enable and write-disable the sector. The next 15 sectors contain a second-stage bootstrap program.