MKBT, Make Bootable

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Create any boot- floppy/image from any win32 platform with any media size...

Version 2.0
Last updated on Jan 7, 2003

- What is MKBT?
- Download
- On what platforms can MKBT be run?
- What is the command line syntax?
- What is so unique about MKBT?
- Are there any other bootsector installers?
- Where can I find the latest version?
- How to build a bootable floppy
- How to build a bootable 2.88MB floppy image file (without the drive)
- How does MKBT work? (technical)
- Bootsector installation
- Bootsector copy (-c)
- Change log

What is MKBT?

MKBT is used for installing bootsectors. It supports FAT, NTFS and RAW bootsectors.

Download

To download MKBT use this link: MKBT v2.0 (30KB)

On what platforms can MKBT be run?

MKBT is compiled as a win32 executable and runs on:

Windows 95/98/ME (FAT)
Windows NT4/2000/XP (FAT and NTFS)

What is the command line syntax?

MKBT usage
Usage: mkbt [switches] <source> <target> <source> The source file/drive which contains the bootsector to install <target> The target file/drive to install the bootsector on Switches: -v Verbose mode -c Copy mode (no install) used for copying the bootsector(s) -x Expert mode (do not check drive A or B only) USE WITH CAUTION! -l=<xxx> Set Volume Label to <xxx> Returns errorlevel 0 when OK, 1 when some error occurred. Examples: To install bootsector from file "bootsect.bin" onto drive A: -> mkbt c:\os\dos622\bootsect.bin a: To install bootsector from file "bootsect.bin" onto floppy image "288.img" -> mkbt c:\os\dos622\bootsect.bin c:\tmp\288.img To copy bootsector from a bootable floppy in drive A: to a file called "bootsect.bin" -> mkbt -c a: c:\os\dos622\bootsect.bin

MKBT usage


Usage:
  mkbt [switches] <source> <target>

  <source>  The source file/drive which contains the bootsector to install
  <target>  The target file/drive to install the bootsector on

  Switches: -v        Verbose mode
            -c        Copy mode (no install) used for copying the
                      bootsector(s)
            -x        Expert mode (do not check drive A or B only)
                      USE WITH CAUTION!
            -l=<xxx>  Set Volume Label to <xxx>

  Returns errorlevel 0 when OK, 1 when some error occurred.

  Examples:
    To install bootsector from file "bootsect.bin" onto drive A:
    -> mkbt c:\os\dos622\bootsect.bin a:

    To install bootsector from file "bootsect.bin" onto floppy image "288.img"
    -> mkbt c:\os\dos622\bootsect.bin c:\tmp\288.img

    To copy bootsector from a bootable floppy in drive A: to a file called
    "bootsect.bin"
    -> mkbt -c a: c:\os\dos622\bootsect.bin

What is so unique about MKBT?

Unique things about MKBT are:

It supports transferring a bootsector to floppy images. This allows you to create a bootable 2.88MB floppy image without needing a 2.88MB floppy drive. See How to build a bootable floppy image file
It is a win32 executable (not Dos)

Are there any other bootsector installers?

Yes, I've found one other bootsector installer, "bootable.exe"written by Alexei A. Frounze. It is a Dos executable and only supports transferring a bootsector from file to floppy drive (A: or B:).

Where can I find the latest version?

The latest version can be found on http://www.nu2.nu/mkbt/

How to build a bootable floppy

You can use any Dos version, any Dos supported floppy disk size to build your bootable floppy. For each Dos version you must have the following 4 boot files:

The bootsector in a file called "bootsect.bin"
You can capture the bootsector to a file using: mkbt -c a: bootsect.bin
IO.SYS (or IBMBIO.COM for Novell Dos)
MSDOS.SYS (or IBMDOS.COM for Novell Dos)
COMMAND.COM

For this example we will use MS-Windows 98 (version 4.10.1998), therefor we put the files in a folder called "4101998". They must have "normal" attributes (not hidden/system/readonly!).

You can now use makeboot.bat (which is include with the MKBT download zipfile).
makeboot.bat takes one parameter, that is the directory where the Dos bootfiles can be found.

Example: makeboot c:\os\4101998
or when your in the "c:\os" folder, just makeboot 4101998

How to build a bootable 2.88MB floppy image file (without the drive)

Use bfi - Build Floppy Image.

How does MKBT work? (technical)

MKBT copies parts of the bootsector. The bootsector, the very first sector of a floppy disk, is 512 bytes long and looks like this:

FAT Boot sector
Offset	Length	Meaning
0x0	3 bytes	Jump instruction
0x3	8 bytes	OEM Name
0xB	25 bytes	BIOS parameter block
0x24	26 bytes	Extended BIOS parameter block
0x3E	448 bytes	Bootstrap code
0x1FE	2 bytes	End of sector marker

The BIOS parameter block and extended BIOS parameter block contains the information:

BIOS parameter block for FAT volumes
Offset	Length	Meaning
0xB	2 bytes	Bytes per sector
0xD	1 byte	Sectors per cluster
0x0E	2 bytes	Reserved sectors
0x10	1 byte	Number of FATs
0x11	2 bytes	Root entries
0x13	2 bytes	Small sectors
0x15	1 byte	Media type
0x16	2 bytes	Sectors per FAT
0x18	2 bytes	Sectors per track
0x1A	2 bytes	Number of heads
0x1C	4 bytes	Hidden sectors
0x20	4 bytes	Large sectors

Extended BIOS parameter block for FAT volumes
Offset	Length	Meaning
0x24	1 byte	Physical disk number
0x25	1 byte	Dos: Current head NT: Dirty flag
0x26	1 byte	Signature
0x27	4 bytes	Volume serial number
0x2B	11 bytes	Volume label
0x36	8 bytes	Filesystem ID

Bootsector installation

Below are the steps MKBT takes to install a bootsector:

Steps for bootsector installation
Step	Source sector	Buffer 1	Buffer 2	Target sector
1.	Read source sector in buffer 1
2.			Read target sector in buffer 2
3.		Transfer bootsector parts from buffer 1 to buffer 2
4.			Write buffer 2 to target sector

Bootsector copy (-c)

MKBT v1.3 (and higher) copy bootsector option copies the complete bootsector!
(previous versions only copied those sections that where needed to install it)

Change log

Change log for MKBT