FORMAT(DOS) UNIX System V FORMAT(DOS)
Name
format - formats the disk in the specified drive to accept
MS-DOS files
Syntax
format drive:[/1][/4][/8] [/n:xx][/t:yy][/v][/s]
format drive:[/1][/b][/n:xx] [/t:yy]
Description
The format command initializes the directory and the file
allocation tables on a disk. You must use this command to
format all new disks before MS-DOS can use them.
When using the commands, you must specify the drive that you
want to format. The format command then uses the drive type
to determine the default format for a disk.
When you format a hard disk, format prompts you to verify
the volume label:
Enter current Volume Label for drive x:
If your hard disk does not have a volume label, press
<Return>. (Note: If your hard disk has never been formatted
before, or if it has a bad boot sector, format will not
prompt you for a volume label.)
If the volume label that you enter does not match the label
on the hard disk, format displays the following message:
Invalid Volume ID Format failure
Otherwise, it continues:
WARNING, ALL DATA ON NON-REMOVABLE DISK
DRIVE x: WILL BE LOST! Proceed with Format (Y/N)?_
If you want to format your hard disk, enter y. If not,
enter n.
The switches are:
/l Formats a disk for single-sided use, even if the disk
or drive is double-sided. If the drive is double-
sided and you don't specify this switch, you won't be
able to use the formatted disk in a single-sided
drive.
/4 Formats a double-sided disk in a high-capacity disk
drive. Note, however, that if you are using a single-
or double-sided drive, you may not be able to reliably
read disks formatted with this switch.
/8 Formats a disk for 8 sectors per track. If you do not
specify this switch, format defaults to either 9 or 15
sectors per track (depending on the type of drive
being used). Note that format always creates either 9
or 15 sectors per track; when you specify this switch,
though, it tells MS-DOS to use only 8 sectors per
track.
/b Formats a disk with 8 sectors per track and allocates
space for the hidden system files. If you use this
switch with the format command, you can place any
version of MS-DOS on the disk by using that version's
sys command. If you don't use this /b switch, you can
place only MS-DOS 3.2 on the disk by using the sys
command. You cannot use the /s or the /v switch with
the /b switch.
/n:xx Specifies the number of sectors per track that format
uses to format a floppy disk.
/t:yy Specifies the number of tracks that format places on a
floppy disk.
/v Prompts for a volume label after the disk is
formatted. A volume label identifies the disk and can
be up to 11 characters in length. An example of a
volume label is PROGRAMS.
/s Must be the last switch that you type. This switch
copies the operating system files from the disk in the
default drive to the newly formatted disk. The files
are copied in the following order:
io.sys
msdos.sys
command.com
If the operating system is not on the default drive, format
prompts you to insert a system disk in the default drive (or
in drive A if the default drive is nonremovable).
When formatting is complete, format displays a message
showing the total disk space, any space marked as defective,
the total space used by the operating system (when you use
the /s switch), and the space available for your files.
The following table shows which switches you can use for
certain types of disks:
DISK TYPE VALID SWITCHES
________________________________________
160/180 Kbytes /l /4 /8 /b /n /t /v /s
320/360 Kbytes /1 /4 /8 /b /n /t /v /s
720 Kbytes /n /t /v /s
1.2 Mbytes /n /t /v /s
hard disk /v /s
You should not format disks on drives used in assign, join,
or subst, and you cannot format disks over a network.
Exit codes
The format command returns the following exit codes:
0 Successful completion
3 Terminated by user (<CTL>c)
4 Fatal error (any error other than 0, 3, or 5)
5 N response to hard disk prompt, ``Proceed with format
(Y/N)?''
You can check these exit codes by using the errorlevel
condition with the if batch processing command.
Examples
To format a floppy disk in drive A and put the operating
system on it, enter the following:
format a:/s
And to format a floppy disk in drive A for use with data,
enter the following:
format a: /v
The /v switch causes format to prompt you for a volume
label. You should type a label since it will help you
identify the data that the disk contains.
Notes
Formatting destroys any previously existing data on a disk
and ignores drive assignments created with the assign
command.
format is an external command.
FORMAT(DOS) (printed 8/16/89) FORMAT(DOS)