A)Hard Disk Partitions
     Hard disks are usually so large that they can contain more 
than one type of operating system. For example, you can have DOS 
3.3 manage one part of a disk and UNIX manage another. Each of 
these sections is called a partition. You can have from one to
four partitions on a disk.
     Partitions are used to make the hard disk, especially a very 
large one, a more economical investment. They allow you to 
effectively have up to four completely different computer systems 
resident in one set of hardware. However, since they do not share 
a common software environment, they cannot share data directly. 
     Two types of partitions can be set up for DOS: a primary DOS
partition and an extended DOS partition. The primary DOS
partition is the partition that contains DOS and is the first 
partition on the disk. This is the only partition that must be on 
the disk if your disk is no larger than 32 megabytes. The 
extended DOS partition is a separate partition that cannot be 
used for booting, but can be divided into separate logical 
drives. 
     If you have more than 32 megabytes available on one hard 
disk, you will need to create an extended DOS partition, which is 
assigned the next logical drive letter. For example, if you had a 
60-megabyte hard disk drive, and wanted access to all of it, you 
would create a 32-megabyte primary partition and a 28-megabyte 
extended partition. The primary partition could be accessed as 
drive C, while the extended partition would be called drive D. 
You could also subdivide the extended partition into more logical 
drives (up to the letter Z).
     You must create partitions before using a hard disk drive. 
You will probably take the easiest route by simply making the 
entire disk into one primary partition. The FDISK program 
presented here, however, is necessary in several more advanced 
situations. For example, you may plan on using multiple operating 
systems from the same disk. FDISK will let you set up unique 
partitions for each system. (Each of these would be a primary 
partition, but only one could be designated the active partition, 
the one that will gain control at boot up.) Then again, you may 
be using one of the large hard disks (40 to 70 megabytes) that 
are increasingly common. Since DOS can only access a logical 
drive of 32 megabyte or less, you'll need to partition a larger 
physical drive into multiple logical drives. Only in this way can 
you store and retrieve information on the larger hard disk.
     Note: If your disk is already being used and you wish to
make a new partition, you will have to first back up all of your 
data and then run FDISK from a system diskette. Finally, you'll 
need to reformat your disk before restoring your files to it.
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		  [For related topics, press R]
    SEE ALSO
Configuration of DOS Partitions
Active Partitions, Changing of
Displaying of Partition Information
Deletion of DOS Disk Partitions
A)Configuration of DOS Partitions
     In this section, you will see exactly how to use the FDISK 
command. This procedure is very important, and it can have 
serious consequences if done incorrectly. However, it can also 
make your system more efficient, when done properly. FDISK is 
only usable on hard disk systems.
     Invoking the FDISK command is as simple as typing
	  FDISK
and pressing Return. emember to have your path set properly to
include the directory containing the FDISK command file.) After 
this command creates the appropriate partition(s), you must then 
logically format the disk.
     Warning: All data on your disk will be destroyed when you
create partitions with FDISK.
     When you first execute FDISK, the screen will clear and the 
FDISK Options screen will appear. This contains the menu used to 
get around in FDISK, as shown in the screen below.
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     FDISK Options
     Current Fixed Disk Drive: 1
     Choose one of the following:
	  1.  Create DOS partition
	  2.  Change Active Partition
	  3.  Delete DOS partition
	  4.  Display Partition Information
     Enter choice: [1]
     Press ESC to return to DOS
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     As you can see, there are four choices. If you have a system 
with more than one hard disk drive, the number in the Current
Fixed Disk Drive: 1 line would be changed to the number of drives
in your system. Also, a fifth option, Select Next Fixed Disk
Drive, would be displayed on the screen. You can work on only one
hard disk drive at a time, but you can switch from the drive you 
are working on to another drive. For now, let's assume you have 
one hard disk drive and that the screen below is what you see.
    Creating a Partition
     The first option on the FDISK Options menu is to create a 
DOS partition. Since you are using DOS, and not another operating 
system such as UNIX, you can only create DOS partitions. Should 
you wish to put another operating system onto the disk, that 
system would have its own version of FDISK and could then create 
its own partitions next to DOS'.
     Tip: If you plan to use your hard disk to support another
operating system, do not partition the whole disk. Leave some 
room so that another system can be loaded onto the disk.
     Choosing the first option to create a DOS partition results 
in the screen below. 
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     Create DOS Partition
     Current Fixed Disk Drive: 1
	  1.  Create Primary DOS partition
	  2.  Create Extended DOS partition
     Enter Choice: [1]
     Press ESC to return to FDISK Options
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     If you select option 2 at this point, intending to create an 
extended DOS partition before creating a primary partition, DOS
will display a message indicating that you cannot do so, and will 
suggest that you press Esc to return to the main FDISK Options 
menu. Assuming you are starting from scratch, you would select 
choice 1 to create the primary DOS partition. You will then see 
the screen shown below.
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     Create Primary DOS Partition
     Current Fixed Disk Drive: 1
     Do you wish to use the maximum size
     for a DOS partition and make the DOS
     partition active (Y/N).........? [n]
     Press ESC to return to FDISK Options
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     If you want to use the whole disk for DOS, then you answer Y 
on this screen. Doing so makes DOS use the whole disk. The 
computer will allocate the entire disk, and then come back with 
the message
	  System will now restart
	  Insert DOS diskette in drive A:
	  Press any key when ready . . .
Since you just created the partition, there is still nothing on 
the hard disk. The system must be rebooted from the disk drive. 
You can now format the entire hard disk just as you would a 
floppy diskette.
     If you answer N, you have the opportunity to create a 
smaller partition, as shown in the screen below. As you can see, 
there are 305 cylinders available on the total disk. A hard disk
consists of several platters, similar to a diskette; each platter 
consists of a series of concentric tracks made up of sectors. 
Each platter lies above another and is read by a different disk 
head. Viewed vertically, a series of tracks (with the same track 
number, but on different platters) located one above the other 
constitute a cylinder. The brackets in the screen shown below 
indicate the place where you may enter a number for cylinders 
that is less than the default maximum (305 on this disk).
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     Create Primary DOS Partition
     Current Fixed Disk Drive: 1
     Total disk space is 305 cylinders.
     Maximum space available for partition
     is 305 cylinders.
     Enter partition size...........: [ 200]
     No partitions defined
     Press ESC to return to FDISK Options
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     Notice that the second-to-last line on the screen tells you 
that no partitions have been defined yet. If you are using your 
disk for DOS alone, you should accept the default maximum 
cylinder value. All disk space will then be available for DOS and 
your DOS files. If you plan on splitting up your disk between DOS 
and another operating system, however, you'll have to decide for 
yourself what percentage of total disk space is needed for the 
other operating system. In this example, you intend to create an 
extended DOS partition, so 200 was entered for the number of 
cylinders in the primary DOS partition.
     Entering 200 results in the screen shown below. This screen 
tells you that the first partition on drive C is a primary DOS 
partition (PRI DOS) that starts at cylinder 0 and ends at 
cylinder 199, constituting a total of 200 cylinders. 
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     Create Primary DOS Partition
     Current Fixed Disk Drive: 1
     Partition Status    Type   Start    End   Size
      C:  1             PRI DOS     0    199    200
     Primary DOS partition created
     Press ESC to return to FDISK Options
----------------------------------------------------------------
     Pressing Esc at this point returns you to the FDISK Options 
menu. If you again try to create a primary partition, DOS will 
show the following message on your screen:
	  Primary DOS partition already exists.
	  Press ESC to return to FDISK Options
     Note: There can only be one primary DOS partition. When DOS
boots up, the system files from this partition are loaded into 
memory for your operations. In this example, you have only used 
200 cylinders out of a possible 305, so you can make an extended 
DOS partition. To do so, you select choice 1 (create a DOS 
partition) on the FDISK Options menu and then select choice 2 
(create Extended DOS partition) on the Create DOS Partition menu.
     The resulting screen, shown below, allows you to create an 
extended DOS partition. This screen tells you the current 
partition information- -that is, that there are 305 total 
cylinders available for use- -and also tells you that 105 
cylinders remain unused. The 105 value is used as the default 
entry at this stage. You only need to type in a number over the 
105 to override the default. In the screen below, 55 was entered 
for the desired extended DOS partition, leaving 50 cylinders 
unused on the disk for another operating system.
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     Create Extended DOS Partition
     Current Fixed Disk Drive: 1
     Partition Status    Type   Start   End   Size
      C: 1             PRI DOS      0   199   200
     Total disk space is 305 cylinders.
     Maximum space available for partition
     is 105 cylinders.
     Enter partition size............: [ 55]
     Press ESC to return to FDISK Options
----------------------------------------------------------------
     The screen will now clear, redisplay the partition 
information (including that on the new extended DOS partition), 
and print the message
	  Extended DOS Partition created
	  Press ESC to return to FDISK Options
near the bottom of the screen. Pressing Esc will result in the 
next step of the process (see screen below).
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     Create Logical DOS Drive(s)
     No logical drives defined
     Total partition sized is	55 cylinders.
     Maximum space available for logical
     drive is	55 cylinders.
     Enter logical drive size..........:  [  45]
     Press ESC to return to FDISK Options
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     Since you have just created an extended DOS partition, DOS 
wants to know if you want to create logical drives within this 
new partition. It tells you the total available cylinders in the 
partition and asks you to enter a size for the logical drive. In 
this example, you enter 45. The resulting screen will contain the 
logical drive information (drive name, starting cylinder, ending 
cylinder, and total cylinders used). 
     Suppose you wanted to create another logical drive, E, using 
the remaining ten cylinders. You could again choose option 1 on 
the FDISK Options menu. You would go again to the Create DOS 
Partition menu, but there would be one new choice displayed:
	  3. Create logical DOS drive(s) in
               the Extended DOS partition
This would bring you back to the screen for defining logical 
drives, where you could then enter the information for drive E. 
Going through this same sequence again in order to use the 
remaining ten cylinders will result in the screen below. Notice 
that the cylinder numbers are within the bounds of the extended 
DOS partition. You are told that DOS created two logical drives, 
D and E, with sizes of 45 and 10 cylinders. Furthermore, you're 
reminded that no more available space remains for any other 
logical drives. Press Esc, and you will once again be back at the 
FDISK Options menu.
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     Create Logical DOS Drive(s)
     Drv  Start   End	Size
      D:    200   244	  45
      E:    245   254	  10
     All available space in the Extended DOS
     partition is assigned to logical drives.
     Logical DOS drive created, drive letters 
     changed or added
     Press ESC to return to FDISK Options
----------------------------------------------------------------
     If you try to create another extended partition, you will 
get a partition information screen and the message
	  Extended DOS partition already exists.
	  Press ESC to return to FDISK Options
------------------------------------------------------------------
		  [For related topics, press R]
    SEE ALSO
Active Partitions, Changing of
Deletion of DOS Disk Partitions
Displaying of Partition Information
FDISK Command
Hard Disk Partitions
A)Active Partitions, Changing of
     The active partition is the partition that is used to boot
the system. It is the default partition. Choosing option 2 on the 
main FDISK Options menu leads you to a menu like that shown in 
the screen below, in which the partition information is displayed 
along with the total number of cylinders available on the disk. 
FDISK now wants to know the number of the partition that you wish 
to make active.
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     Change Active Partition
     Current Fixed Disk Drive: 1
     Partition Status   Type   Start   End   Size
      C: 1            PRI DOS      0   199   200
         2            EXT DOS    200   254    55
     Total disk space if  305 cylinders.
     Enter the number of the partition you
     want to make active.............: [2]
     Partition selected (2) is not bootable,
     active partition not changed.
     Press ESC to return to FDISK Options
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     If you enter the number 2, as shown in the figure, DOS will 
inform you that only the primary DOS partition (1) may be made 
active. Type the number 1 so that the primary DOS partition will 
have control when the system comes up. Pressing Return will 
result in the adjusted partition information display seen below.
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     Change Active Partition
     Current Fixed Disk Drive: 1
     Partition Status   Type   Start   End   Size
      C: 1        A   PRI DOS      0   199    200
         2            EXT DOS    200   254     55
     Total disk space is  305 cylinders.
     Partition 1 made active
     Press ESC to return to FDISK Options
----------------------------------------------------------------
     Notice the letter A on the first line of this display. An A 
under Status tells you that partition 1 is the active partition.
Pressing Esc takes you back to the FDISK Options menu. 
------------------------------------------------------------------
		  [For related topics, press R]
    SEE ALSO
Configuration of DOS Partitions
Deletion of DOS Disk Partitions
Displaying of Partition Information
FDISK Command
Hard Disk Partitions
A)Displaying of Partition Information
     Option 4 on the FDISK Options menu is used to display 
information about the partitions. This is useful because no extra 
functions will be executed at the same time; you can simply look 
at the information. Choosing option 4 yields the screen shown 
below.
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     Display Partition Information
     Current Fixed Disk Drive: 1
     Partition Status   Type   Start   End   Size
      C: 1        A   PRI DOS      0   199    200
         2            EXT DOS    200   254     55
     Total disk space is   305 cylinders.
     The Extended DOS partition contains
     logical DOS drives. Do you want to
     display logical drive information?  [Y]
     Press ESC to return to FDISK Options
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     The information at the top of the screen is familiar by now. 
But what if you want to see information about the logical drives 
that have been defined? Look at the bottom half of the screen, 
where you are asked if you want to see this information. Replying 
with Y results in a display of information about these logical 
drives (see the screen below). Pressing Esc at this point will 
return you to the FDISK Options menu.
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     Display Logical DOS Drive Information
     Drv   Start   End	 Size
     D:      200   244	   45
     E:      245   254	   10
     Press ESC to return to FDISK Options
----------------------------------------------------------------
------------------------------------------------------------------
		  [For related topics, press R]
    SEE ALSO
Active Partitions, Changing of
Configuration of DOS Partitions
Deletion of DOS Disk Partitions
FDISK Command
Hard Disk Partitions
A)Deletion of DOS Disk Partitions
     As with most things, what DOS giveth, DOS can taketh away- -
with a little prodding from you. Selecting choice 3 on the FDISK 
Options menu produces the Delete DOS Partition menu, shown below.
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     Delete DOS Partition
     Current Fixed Disk Drive: 1
     Choose one of the following:
	  1.  Delete Primary DOS partitions
	  2.  Delete Extended DOS partition
	  3.  Delete logical DOS drive(s) in
                  the Extended DOS Partition
     Enter choice: [ ]
     Press ESC to return to FDISK Options
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     Using this menu, you can delete any of the information 
you've already set up. You may want to expand or contract other 
partitions, or you may no longer want to use a partition in the 
manner you originally designed. In any case, you can only make 
changes in a certain order. You cannot delete the primary DOS 
partition without first deleting the extended DOS partition. If 
you try, DOS will give you this message:
	  Cannot delete Primary DOS partition on
	  drive 1 when Extended partition exists
	  Press ESC to return to FDISK Options
     In addition, you cannot delete an extended DOS partition 
without first ``undefining'' (deleting) the logical drives in 
that partition. Trying to delete the extended DOS partition 
before deleting the drives in it will simply display the current 
partition information with the patient message
	  Cannot delete Extended DOS partition
	  while logical drives exist.
	  Press ESC to return to FDISK options
     Choice 3 in the Delete DOS Partition menu is probably the 
first selection you will need to make; you work your way 
backwards through the order in which you created things. 
ctually, you will find that this is a fairly natural process.)
Selecting choice 3 produces the screen shown below, which 
contains the logical drive information and the size of the 
extended DOS partition the drives are in. You are also warned 
that any data contained in the logical disk drive to be deleted 
will also be deleted. If you still want to delete the drive, 
simply enter the drive identifier. You will then be asked to 
confirm this step. In the screen below, you have selected drive E 
to delete first, and confirmed the choice by typing Y. If you had 
entered N, you would have been returned to the FDISK Options 
menu.
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     Delete Logical DOS Drive
     Drv   Start   End	 Size
      D:    200    244	   45
      E:    245    254	   10
     Total partition size is   55 cylinders.
     Warning! Data in the logical DOS drive
     will be lost. What drive do you wish
     to delete.........................? [e]
     Are you sure......................? [y]
     Press ESC to return to FDISK Options
----------------------------------------------------------------
     Once FDISK deletes the logical drive, it updates the display 
at the top of the screen and asks for another drive to delete. If 
you wanted to regain all the space used by this partition, you 
would then enter drive D, confirm your entry, and end up with the 
screen shown below. Pressing Esc twice at this point would 
bring you back up through the menu screens to the main FDISK 
Options menu.
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     Delete Logical DOS Drive
     Drv   Start   End	 Size
	D: drive deleted
	E: drive deleted
     Total partition size is  55 cylinders.
     All logical drives deleted in the
     Extended DOS partition
     Press ESC to return to FDISK Options
----------------------------------------------------------------
     Now that the logical drives are gone, you can delete the 
extended DOS partition itself if you choose to do so. Choosing 
option 2 on the Delete DOS Partition menu results in the familiar 
form of an FDISK screen (see below). Again, you are shown the 
partition information display, warned that data will be lost, and 
asked if you really want to delete the extended DOS partition. 
----------------------------------------------------------------
     Delete Extended DOS Partition
     Current Fixed Disk Drive: 1
     Partition Status   Type   Start   End   Size
      C: 1        A    PRI DOS     0   199    200
         2             EXT DOS   200   254     55
     Warning! Data in the Extended DOS
     partition will be lost. Do you wish
     to continue.......................?  [y]
     Press ESC to return to FDISK Options
----------------------------------------------------------------
     If you reply Y, the screen will be updated to show only the 
primary DOS partition and the message
	  Extended DOS partition deleted
	  Press ESC to return to FDISK Options
Press Esc to return once again to the FDISK Options menu.
------------------------------------------------------------------
		  [For related topics, press R]
    SEE ALSO
Active Partitions, Changing of
Configuration of DOS Partitions
Displaying of Partition Information
FDISK Command
Hard Disk Partitions
A)active partition
The section of a hard disk containing the operating system to be 
used when the hardware powers up.
------------------------------------------------------------------
		  [For related topics, press R]
    SEE ALSO
hard disk
hardware


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