FDFORMAT - Format Disks with higher Capacity
LICENSE
-------
This program is a public-domain product for private and
educational use. You may freely copy and use it without any
charge.
This program must not be sold for profit. An adaequate fee may be
requested for copying, shipping and handling when redistributing
this program.
You may modify and improve this program, but the executable
program must show a message that your version has been modified.
If you find, that this program is worth contributing for it, do
not hesitate to send cash, check, 3«"-diskettes or something else.
THANKS
------
Special thanks to the following people:
Jochen Roderburg, Cologne, Germany: For suggestions and
improvements to support compatibility with several BIOS-Versions.
Michael Ho, Lincoln, Nebraska: For an improvement in sector
sliding.
Joel Armengaud, Paris, France: For supporting automatic detection
of 720 kByte diskettes in FDREAD.
J”rg-Stefan Sell, Essen, Germany: For supporting an interface
routine to less compatible XT computers.
COMMENTS AND PROBLEMS
---------------------
Comments, improvements, suggestions and problems may be sent to
the Author
Christoph H. Hochst„tter
Carl-Strehl-Strasse 20
D-3550 Marburg
West-Germany
Phone: +49 6421 14618 (voice/BTX)
+49 6429 6209 (BBS)
E-Mail: HAMPE2@DMRHRZ11.BITNET (Bitnet/Internet)
Christoph Hochstaetter on 2:243/22 (Fido)
SYSTEM REQUIREMENTS
-------------------
IBM or compatible Computer
DOS 3.20 or above
FEATURES OF FDFORMAT
--------------------
FDFORMAT is a replacement for the DOS-Format program, which has
the following advantages:
1) Supporting 3«"-1.44 MB drives with any BIOS-Versions in ATs and
Clones. This saves you a lot of money, you would need for a new
BIOS-Version.
2) Formatting and using of 720/820 kByte disks in AT 5¬"-1.2 MByte
Drives using cheap double-density (DD) disks.
3) Increasing the capacity of your disks up to 300 kByte
additional storage.
4) Supporting 3«"-360 kByte format. This is useful, when you want
to make copies of 5¬"-disks to 3«"-Disks using DISKCOPY
5) Enhance speed of your diskette I/O up to 100% with sector
sliding. This is a method of physical ordering sectors in a
way, that your drive is ready to read the next logical sector,
when your head advances one track.
6) Improved BOOT-Sector, which automatically boots from harddisk,
if the diskette in drive A: is not a system disk. This allows
you to leave the diskette in drive A:, when you reboot the
system.
GETTING STARTED
---------------
To make full use of FDFORMAT, you have to make FDREAD.EXE
resident on non-XT computers. There are two ways to make FDREAD
resident:
1) Typing FDREAD from the DOS-Command-Prompt or inserting it into
your AUTOEXEC.BAT file.
2) Loading FDREAD as a Device-Driver by inserting
DEVICE=[path]FDREAD.EXE into your CONFIG.SYS File.
Yes, you can also load FDREAD as a Device-Driver. When you do so,
it will take only 160 Bytes of main memory. If you install it from
the DOS-Command-Line, it will take 224 Bytes. DOS 4.00+ users
should not use the INSTALL= statement of CONFIG.SYS, but also the
DEVICE= statement.
Note for users of High-Memory Loaders like QEMM, QRAM, Mov'em or
386-MAX:
Do not load FDREAD high. FDREAD automatically loads high, if it
installed from AUTOEXEC.BAT or the DOS-Command-Line. This feature
works with any memory manager supporting UMBs.
FDREAD is needed for special formats only. Any standard format can
be used without FDREAD.
USING FDFORMAT
--------------
The general Syntax for FDFORMAT is:
FDFORMAT <drive> [options]
<drive> may be A: or B:. FDFORMAT does not format harddisks.
Options begin with a letter or number. Options may be preceeded by
'/' or '-'. If you do not preceed options with '/' or '-', you
must seperate the options with spaces. '.' and ':' are always
ignored. So the following commands will all format a 1.44 MByte
Disk in Drive A:
FDFORMAT A: /F:1.44
FDFORMAT A: -F144
FDFORMAT A: F144
You may precede all numbers with a $-sign to indicate, that they
are hexadecimal numbers.
OPTIONS USED IN FDFORMAT
------------------------
The most important option is the F-Option. The F-Option determines
the general Format, which is used for the target diskette.
The following table shows, which parameters are allowed for the F-
Options and for which type of Disk-Drive:
F-Opt Format 360k-Drive 720k-Drive 1.2M-Drive 1.44M-Drive
----- --------------- ---------- ---------- ---------- -----------
F160 160 kByte Disk yes FDREAD yes FDREAD
F180 180 kByte Disk yes FDREAD yes FDREAD
F200 200 kByte Disk FDREAD FDREAD FDREAD FDREAD
F205 205 kByte Disk FDREAD FDREAD FDREAD FDREAD
F320 320 kByte Disk yes FDREAD yes FDREAD
F360 360 kByte Disk yes FDREAD yes FDREAD
F400 400 kByte Disk FDREAD FDREAD FDREAD FDREAD
F410 410 kByte Disk FDREAD FDREAD FDREAD FDREAD
F720 720 kByte Disk no yes FDREAD yes
F800 800 kByte Disk no FDREAD FDREAD FDREAD
F820 820 kByte Disk no FDREAD FDREAD FDREAD
F120 1.2 MByte Disk no no yes yes
F12 1.2 MByte Disk no no yes yes
F144 1.44 MByte Disk no no FDREAD yes
F14 1.44 MByte Disk no no FDREAD yes
F148 1.48 MByte Disk no no FDREAD yes
F16 1.6 MByte Disk no no no FDREAD
F164 1.64 MByte Disk no no no FDREAD
F168 1.68 MByte Disk no no no FDREAD
F172 1.72 MByte Disk no no no FDREAD
FDREAD in the above table means, that this format will work only,
if FDREAD is installed.
The other options are:
1 : Format single sided Disk (provided for DOS-FORMAT-
compatibility).
4 : Format Standard 360 kByte Disk (provided for DOS-FORMAT-
compatibility).
8 : Format 8 sector Disk (provided for DOS-FORMAT-
compatibility).
Bnnn: Use Disk-Type Byte nnn (for use with older BIOS Versions).
Cnnn: Use nnn Sectors per Cluster (nnn = 1 or 2).
Dnnn: Use nnn Root-Directory-Entries (nnn = 1-224).
Gnnn: Use Gap-Length of nnn (for use by experts only).
Hnnn: Use nnn heads (nnn = 1 or 2).
Innn: Use an Interleave of nnn (for use by experts only).
K : Do not wait for any keyboard input, when starting FDFORMAT.
(Useful, when starting FDFORMAT from batch files).
Mnnn: Use Media Byte nnn (Useful for ATARI formats).
Mnnn: Use Media-Descriptor-Byte nnn. (Useful when formatting ATARI
ST disks).
Nnnn: Use nnn Sectors.
O : Format 720 kByte Disk for use with AT&T Olivetti M24/M28.
R : Do not verify Disk (and save 33% time).
S : Make System-Disk.
Snnn: Use nnn Sectors.
Tnnn: Use nnn Tracks.
V : Write Label to Disk.
Xnnn: Slide nnn Sectors, when head changes.
Ynnn: Slide nnn Sectors nnn, when track changes.
Examples:
FDFORMAT A: /4 (format 360 kB disk)
FDFORMAT A: /F:1.72 (format 1.72 MB disk)
FDFORMAT A: /T:80 /N:9 (format 720 kB disk)
FDFORMAT A: /O (format 720 kB disk for AT&T M24/28)
FDFORMAT A: /F:720 M$F7 B$54 (format 720 kB disk for ATARI ST)
FDFORMAT A: /F:12 D64 (format 1.2 MB disk with 64 RDEs)
FDFORMAT A: /F:410 R (format 410 kB Disk without verify)
DETAILED DESCRIPTION OF OPTIONS
-------------------------------
The Tnnn option - Use nnn Tracks
--------------------------------
This option tells FDFORMAT, how many tracks are to be used. A
Standard 360 kB diskette has 40 tracks, all other standard formats
have 80 tracks. You can set this option to 1-41 for an 360 kB
drive and to 1-82 for all other drives. The more tracks you use,
the more storage you will receive. Some drives allow even more
than 41 or 82 tracks, but you may have trouble, when trying to
read this diskette on another disk drive. The default is 40 for a
360 kB Drive and 80 for all other drives.
Example: FDFORMAT A: /T:41 (format a disk with 41 Tracks. This
will give you 369 kB storage in a 360 kB drive)
The Nnnn option - Use nnn Sectors per Track
-------------------------------------------
This option determines the number of sectors per track you will
use. The standard and default values for the different formats
are:
disk format standard value maximum value possible
----------- -------------- ----------------------
360 kB 9 10
720 kB 9 10
1.2 MB 15 18
1.44 MB 18 21
You may use this option to increase the storage of your diskette
too.
Example: FDFORMAT A: /N:10 (format a disk with 10 sectors. This
gives you 400 kB storage in a 360 kB drive).
The Hnnn option - Use nnn sides (1 or 2)
----------------------------------------
You can set this option to 1 or 2. The default is always 2.
Normally you do not need this option, since single-sided disks are
rarely used.
Using T,N and H together
------------------------
These three options determine your diskette storage. The formula
for the diskette storage is:
tracks * sectors * sides
storage in kB = ------------------------
2
Since diskettes use usually 2 sided, you can simplify this formula
to:
storage in kB = tracks * sectors
Examples: FORMAT A: /T:80 /N:9 /H:2 (format a 720 kB disk)
FORMAT A: /T:82 /N:10 /H:2 (format a 820 kB disk)
FORMAT A: /T:40 /N:9 /H:2 (format a 360 kB disk)
FORMAT A: /T:41 /N:10 /H:2 (format a 410 kB disk)
You can use the F-Option (described above) as a shortcut for the
T, H and N options (eg. FORMAT A: /F:1.44 is equal to FORMAT A:
/T:80 /N:18 /H:2).
Note: Always use High-Density-Diskettes when you format with more
than 11 sectors/track and always use double-density-disks, when
you format with 10 sectors and below.
At least here is a table, which values are maximum for T, H and N.
Drive and disk max T max N max H Storage
------------------------------ ----- ----- ----- -------
360 kB drive with DD-diskette 41 10 2 410 kB
720 kB drive with DD-diskette 82 10 2 820 kB
1.2 MB drive with DD-diskette 82 10 2 820 kB
1.2 MB drive with HD-diskette 82 18 2 1.48 MB
1.44 MB drive with DD-diskette 82 10 2 820 kB
1.44 MB drive with HD-diskette 82 21 2 1.72 MB
The Cnnn option - Use nnn sectors per cluster (1 or 2)
------------------------------------------------------
A cluster is the minimum allocation unit DOS can handle. DOS
supports 1 or 2 sectors per cluster for floppy disks. If you
specify /C:1 space is allocated in 512 Bytes steps. /C:2 means
that space is allocated in 1024 Byte steps. You can optimize your
disk organization, if you use /C:1, when you plan to store "many
small" files and specify /C:2, when you plan to store "few large"
files on the disk to be formatted. The default is /C:1 for high
density disks and /C:2 for double density disks
Example: FORMAT A: /F:360 /C:1 (format a 360 kB disk with 1 sector
per cluster)
Note: A blank formatted disk with /C:2 always has more bytes free
than with /C:1. But when files are stored to the disk, your disk
space will be handled more dynamically.
The Dnnn option - Use nnn Root-Directory-Entries
------------------------------------------------
This option determines the number of Root-Directory-Entries. The
default is 112 for double density disks and 224 for high density
disks. This value can be reduced to get additional space on disk
or increased up to 240 to reserve for space for files in the root
directory. This option does not affect any of your subdirectories.
Subdirectories are dynamically allocated. You only have to
determine the size of root directory. Legal values for disks with
1 sector per cluster are 16, 32, 48,.... and for disks with 2
sectors per cluster 16,48,80,.... if you specify a value between
two legal values, it will be increased to next legal value
automatically.
Example: You need a disk that will not have more than 40 files in
the root directory. So type: FDFORMAT A: /D:40. You will get a
disk with 48 root directory entries and you have more space for
data.
The O option - Format a disk for AT&T/Olivetti M24/M28 Computers
----------------------------------------------------------------
This option is actually a shortcut for /T:80 /N:9 /H:2 /D:144. The
AT&T and Olivetti M24/M28 Computers use 720 kB Disks with 144 root
directory entries. The standard IBM 720 kB format has 112 root
directory entries. So simply use the /O option to format a
diskette in a 5¬"-1.2 MB drive or a 5¬"-720 kB drive.
Example: FDFORMAT A: /O
Note: If you could not read M24/M28 720 kB disks in your 1.2 MB
drive until now, try again with FDREAD installed. It will work
fine.
The Mnnn option - Override media descriptor
-------------------------------------------
FDFORMAT uses the same media descriptor byte as DOS-Format would
do. If you override this value, this has no effect under DOS 3.3x
or DOS 4.0x. But you may not be able to read the disk under DOS
3.2x. This option was added to support to format disks for the
ATARI ST. Refer to the ATARI Documentation to set the correct
Values for the media descriptor and track, heads, sectors.
The R option - Do not verify disk
---------------------------------
The R option skips verifying each track after it has been
formatted. This saves 33%-50% of time during formatting a
diskette. The disadvantage is that errors on the diskette are not
detected. A typical example for missing error detection is typing
FDFORMAT A: /R in an 1.2 MB drive with a double density disk
inserted. FDFORMAT will not report any errors in this case. If you
are sure that you have a good diskette and you specified no wrong
parameters, the /R option is a good choice to save time.
The K option - No keyboard input
--------------------------------
The K option suppresses the message "Insert new disk in drive...."
and starts formatting immediately, after FDFORMAT is started. This
is useful, if you want to start FDFORMAT from a batch file or an
external program. You can also suppress any screen output, if you
add ">NUL" to the FDFORMAT command (See your DOS Manual for piping
input and output). FDFORMAT returns an exit code or errorlevel,
which can be used in batch files. The exit codes are:
Exit Code Meaning
--------- ----------------------------------------------------
0 normal completion
1 syntax error or illegal parameters
2 specified drive cannot be formatted
4 aborted by user (after I/O error)
8 I/O error for config file
16 syntax error or illegal parameters in config file
32 error writing disk label
128 incorrect DOS version (< 3.20)
The S Option - Format system disk
---------------------------------
The S option lets you format a system disk. It copies boot-sector,
DOS-System-file and COMMAND.COM to your disk. FDFORMAT does not do
these task by itself, but calls the DOS-Command SYS to do so. Thus
you must make sure, that SYS.COM or SYS.EXE is in a directory,
which is included in your PATH Environment Variable. The call to
SYS is made to ensure compatibility with any DOS Version.
Note: You cannot create a system disk, which cannot be read
without FDREAD.
Example: FDFORMAT A: /F:360 /S (correct)
FDFORMAT A: /F:410 /S (incorrect, because this format
requires FDREAD)
The 1 Option - Single sided disk
--------------------------------
This is the same as the /H:1 option. provided for syntax
compatibility with DOS-Format.
The 8 Option - 8 sector disk
----------------------------
This is the same as the /S:8 option. provided for syntax
compatibility with DOS-Format.
The 4 option - 360 kB disk
--------------------------
This is the same as the /F:360 option. provided for syntax
compatibility with DOS-Format.
The P option - Does nothing
---------------------------
This option does really nothing in FDFORMAT Version 1.5. It was
provided for compatibility with earlier versions.
The V option - Write volume label
---------------------------------
This option writes a volume label to your disk. You may specify
simply /V. This will prompt you for a volume label. You may also
specify /V:<disklabel>. This will write the name <disklabel> to
your disk.
Example: FDFORMAT A: /F:820 /V (prompts for volume label)
FDFORMAT A: /V:mydisk (Writes volume label MYDISK)
The X and Y options - Do sector sliding
---------------------------------------
These options can be used to enhance the performance of your disk
up to 100%. This is bit difficult to explain. Imagine a standard
360 kB disk. It has 9 sectors on each track numbered 1 to 9.
Normally the sectors on all tracks ordered "1 2 3 4 5 6 7 8 9".
With sector sliding of 1 you order "1 2 3 4 5 6 7 8 9" on track 0,
"9 1 2 3 4 5 6 7 8" on track 1, "8 9 1 2 3 4 5 6 7" of track 2 and
so on.
You can easily imagine, that it takes a little time, when your
diskette drive head steps from one track to another. But your
diskette continues rotating. Without sector sliding your diskette
is positioned to sector 2 or 3 on the next track, when the
stepping is done. It needs nearly a full revolution until sector 1
of the next track can be read. With sector sliding of 1 or 2 your
diskette is positioned exactly on sector 1, when it starts reading
again.
The DOS-Format program always formats with sector sliding 0.
FDFORMAT provides two parameters to do sector sliding. /Xn slides
n sectors, when you change the head, but not the track. /Ym slides
m sectors, when you slide the track. Normally only /Y is useful,
but on some systems, especially XTs, you can reach additional
speed by using /X.
Now, how to determine the correct value for sector sliding. In
general you can say good values for /X are 0-2 and for /Y 0-4. The
default is 0 for /X and /Y. You to experiment with your
configuration, which value is optimal for you. You may reconfigure
your default sector sliding in the FDFORMAT.CFG file (described
later). You have to find out this for each format seperately.
Always good choices are the following:
Disk-Size Good choice for sector sliding
------------------ ------------------------------
320-410 kB /X:1 /Y:3
720-820 kB /X:1 /Y:2
1.2 MB-1.72 MB /X:2 /Y:3
This will improve your diskette perfomance 50%-100% on almost any
system.
Example: FDFORMAT A: /4 /X:1 /Y:2 /R/K/V:SLIDE_DISK
The Innn option - Use Interleave of nnn
---------------------------------------
The I option changes the Interleave factor for diskette format.
Normally the best interleave is 1, thus it takes only 1 revolution
to read an entire track. But there are 2 exceptions to it. When
formatting a 21 sector 3«"-HD disk or a 18 sector 5¬"-HD disk. You
need an interleave of 2 in these cases, because a data sector is
used as GAP. If you do not use an interleave of at least 2, the
disk will become unreadable.
But you do not have to take care about this option, FDFORMAT
automatically determines the best interleave for you (1 or 2).
However you can set your interleave whatever you like, but the
only effect is, that your disk becomes slower.
Example: FDFORMAT A: /I:6 (format a very slow disk)
The Gnnn option - Specify GAP length
------------------------------------
The GAP length is the fill space between two sectors on one track.
As with the Interleave, FDFORMAT determines the best value for
you. You can reduce the GAP length to speed up your diskette. But
this reduces your safety, when storing data, unless you choose an
interleave of 2. And an interleave of drastically slows down your
disk performance. If you want to reduce your GAP length anyway, do
not set it below 32 for high density disks and not below 40 for
double density disks.
For the safety of your data, it is recommended not to modify the
GAP length. Sector sliding is a better method to speed up your
diskette performance and does not affect the safety of your data.
The Bnnn option - Setting the disk type Byte
This option affects to 80286/80386/80486 Computers only and needs
to be set, if you have an incompatible or older BIOS, which does
not support 1.44 MByte Drives. It is configurable in the
FDFORMAT.CFG file described later. This byte is made out of the
following components:
Group Decimal Hexadecimal Meaning
-----------------------------------------------------------------
0 0 Media Type unknown
1 16 10 Media Type known
-----------------------------------------------------------------
32 20 double stepping (40 Tracks)
2 0 0 single stepping (80 Tracks)
-----------------------------------------------------------------
0 0 Data-Transfer-Rate: 500 kBaud
64 40 Data-Transfer-Rate: 300 kBaud
3 128 80 Data-Transfer-Rate: 250 kBaud
-----------------------------------------------------------------
0 0 360 kB Disk in 360 kB Drive, unchecked
1 1 360 kB Disk in 1.2 MB Drive, unchecked
2 2 1.2 MB Disk in 1.2 MB Drive, unchecked
3 3 360 kB Disk in 360 kB Drive, checked
4 4 360 kB Disk in 1.2 MB Drive, checked
5 5 1.2 MB Disk in 1.2 MB Drive, checked
4 7 7 state not defined (3«"-Drive)
-----------------------------------------------------------------
To get the correct value for your format, select one Value out of
each group and add these values. Normally the media type byte is
set correctly, following these rules:
Group 1: Always set to 16
Group 2: 32, if tracks from 1-43, else 0
Group 3: high density disks: always 0
double density disks: 64 for 5¬"-Disks, 128 for 3«"-Disks
Group 4: always set to 3
Why set group 4 always to 3? There is a problem DTK-BIOS. DTK-BIOS
seems not to work with any other value than 3. All other BIOS
Versions I have tested, seem to ignore the Value of Group 4. So it
will be the best choice to set it always to 3. In some few cases.
Your System will not work with the default value. In this case,
try out any value from 0-7 for Group 4. It should work. If you
have determined the correct value, you can write it in the
FDFORMAT.CFG file.
CONFIGURING FDFORMAT WITH FDFORMAT.CFG
--------------------------------------
Before you start setting up a configuration file, you should try,
if all formats will work correctly. FDFORMAT normally
automatically determines the best options for you. If something
seems to fail, then set up a configuration file.
You must also create a configuration file, if you have one of the
following situations.
1) You have an XT with a high density controller to support 1.2
MByte or 1.44 MByte drives.
2) You have an AT and an 1.44 MByte drive, but you cannot install
it with your setup program (e.g. IBM/Advanced diagnostics).
3) You have an XT (like EPSON QX-16 or AT&T/Olivetti M24/M28),
which has one or more 720 kByte drives, that also supports 360
kByte diskettes.
4) You have an 5¬"-720 kByte drive in an AT.
Format of the configuration file FDFORMAT.CFG
---------------------------------------------
The general format for FDFORMAT.CFG is:
<drive>: [XT|AT] [BIOS] [40=n] [80=n] [F=n] [360=n] [720=n]
[1.2=n] [1.44=] [X=] [Y=]
Example for a configuration file:
REM Configure drive B: for 1.44 MByte
B: AT BIOS F=7 360=$B7 720=$97 1.44=$17 X=2 Y=2
REM Configure drive A: for 5¬"-720 kByte
A: AT F=2 BIOS 720=$54 X=0 Y=0
REM All Numbers preceded by a $-sign are hexadecimal
The options in detail:
XT : Tell FDFORMAT that your Computer is an XT or compatible and
does not perform any AT-BIOS functions. This option is only
needed, if FDFORMAT does not automatically recognizes, that
your computer is an XT. This option is also needed, if your
XT supports 720 kByte drives, that can handle 360 kByte
diskettes too.
AT : Tell FDFORMAT that your Computer is an 80286/386(SX) or
80486 Computer or an XT, that supports AT-BIOS functions.
This option is only needed, if FDFORMAT does not recognize,
that you can use AT-BIOS functions. A typical case, where
you need this parameter is, when you have an XT with a high
density controller installed.
BIOS: This option works only with AT-BIOS. It tells FDFORMAT not
to modify the disk type byte directly, as it is the default,
but try to change the format information via BIOS-Calls.
This option should only be used, if FDFORMAT does not work
without this option. The BIOS option has the typical
disadvantage that some BIOS-Versions do not support all
formats for all drives. In this case you must set the disk
type byte for the unsupported format in your configuration
file. This option is described later.
PC40: This option works only with a few XT-BIOS-Versions for 720
kByte drives. You can specify an offset to the physical
drive number, that indicates, that a 40 Track Diskette (360
kByte) is inserted, when calling BIOS-Disk I/O. Normally
this option is set to 0.
PC80: This option works with most XT-BIOS-Versions, that support
720 kByte Drives, who also can handle 360 kByte diskettes.
These are for example AT&T M24/M28 or EPSON-QX16. The most
often used offset is 64. Try 64 first, if it does not work
try 32, 16, 8, 4 or 2. Do not try any other values, it will
not work.
F : This option needs to be set only, if your BIOS does not
support the your type of disk drive. You need this option,
if you have an 1.44 MB drive installed and your BIOS does
not support it. If you want to install this option use the
following values: F=0 for 360 kByte Drive, F=1 for 1.2 MB
drive, F=3 for 720 kB Drive and F=7 for 1.44 MB drive.
360 : Use this option to use another disk type byte for 360 kB
diskettes than the default value of $73. If you have set the
BIOS option, the 360 kByte format will not be set by BIOS,
but directly using this disk type byte. Refer to the B
command line option to see how you can determine the correct
disk type byte.
720 : same as 360, but for 720 kB format.
1.2 : same as 360, but for 1.2 MB format.
1.44: same as 360, but for 1.44 MB format.
X : can be used to override the default of 0 for sector sliding,
when the head changes.
Y : can be used to override the default of 0 for sector sliding,
when the track changes.
Sample Configuration Files
--------------------------
A: XT PC80=64 720 kB drive in XT like AT&T M24
A: AT F=7 1.44 MB drive in AT or XT
A: AT F=1 1.2 MB drive in AT or XT
A: AT F=2 360=$74 720=$57 720 kB 5¬"-Drive in AT
A: AT F=2 360=$73 720=$53 720 kB 5¬"-Drive in AT & DTK-BIOS