FORMAT(8)
NAME
format − format floppy diskette
SYNOPSIS
disk/format [ -t type ] [ -f ] [ -d ] [ -b bfile ] [ -c csize ] [ -l label ] drive [ files ... ]
DESCRIPTION
Format initialises the floppy diskette in the disk file named drive, for example /dev/fd0disk. By default it formats the diskette and copies in the given files. The options are:
-f Do not physically format the disc. Used to install an MS-DOS filesystem on a previously formatted disc. With this option, drive can be a plain file.
-t specify a density and type of disk to be prepared. The possible types are:
3½DD 3½" double density, 737280 bytes
3½HD 3½" high density, 1474560 bytes
5¼DD 5¼" double density, 368640 bytes
5¼HD 5¼" high density, 1146880 bytes
hard Hard disc, used in conjunction with -f to format arbitrary sized plain files.
The default is the highest possible on the device, unless -f is used, in which case the default is 3½HD.
-d add MS-DOS parameter block, file access table (FAT), and root directory to the start of the floppy.
The remaining options have effect only when -d is specified:
-b use the contents of bfile as the bootstrap block installed in sector 0.
-c use a DOS cluster size of csize sectors when creating the DOS FAT.
-l add a label when creating the DOS parameter block.
Again under -d, any files listed are added, in order, to the root directory of the MS-DOS filesystem. The files are contiguously allocated and created with the READONLY attribute set.
The file /os/boot/pc/bb is an example of a suitable bfile to make the diskette a boot diskette. It gets loaded by the BIOS at 0x7C00, reads the root directory into address 0x7E00, and looks at the first root directory entry. If that file is called B.COM, it uses single sector reads to load the file into address 0x10000 and then jumps to the loaded file image.
EXAMPLE
Create a boot floppy on a previously formatted diskette:
disk/format -f -b bb -d /dev/fd0disk /os/boot/pc/b.com
Format an ftl(3) file system:
disk/format -fdt hard ’#’X/ftldata
SOURCE
/appl/cmd/disk/format.b
/os/boot/pc/bb.s