Downloading "tomsrtbt"
Root Boot Disk and
How to Install It

Copyright©2002 by Daniel B. Sedory

The version used on my Linux/UNIX Commands page is:
tomsrtbt 2.0.103

  1) If you run a DOS (or MS-Windows) OS, then download one of the "" files. For example:
  2) If you run a Linux/GNU OS, then get one of the ".tar.gz" archive files. For example: tomsrtbt-2.0.103.tar.gz
Tom's rtbt can be found at various mirrors all over the world. You should begin at Tom's own web site for a list of various locations:
NOTE: The actual download pages may contain many other files (the ibiblio site had over 60 files), so you may need to search a bit to get the tomsrtbt file.

Installing "tomsrtbt" to a Floppy Disk

NOTE: Although virtually all 3.5 inch floppy drives in use today support the creation of 1722 kb floppy diskettes, Tom added a note in his FAQ stating: "... it is possible for an extended format to break a floppy drive, use tomsrtbt at your own risk." Perhaps 'break' is a bit too strong. If you have some old or nonstandard floppy drive or you're just really worried about this, then keep your finger on the POWER or RESET button and look for error messages while listening for any 'bad sounds' while the floppy drive is running, but please don't blame me for any damages!
      (See below: For more info on 1722 kb diskettes.)
IF you really want to practice using Linux/UNIX commands, but refuse to try using tomsrtbt, then send me an email for some alternative disk sets.

For Windows/DOS Users:
    Unzip the files from the .zip archive into a new folder (directory) named: C:\tomsrtbt (so you won't forget where they are). Now you must restart Windows in REAL DOS (not just open a DOS box in Windows!) because we're going to run a small Linux OS in your computer's memory!
    Once you're at a DOS prompt (such as C:\> ) type this:  cd\tomsrtbt   and press the ENTER key. You should then see:
C:\tomsrtbt> . Now you can ENTER  install   to run install.bat (a batch program) which will first load Linux and then start a script file that guides you through the tomsrtbt Boot Disk creation. Place any 3.5 inch HD (high density) floppy diskette into your A: drive. It doesn't matter if it's been formatted or not, since the install program will be formatting it differently anyway.

For Linux/GNU users:
    Extract files from .tar.gz archive and then make sure you're logged in as 'root' before proceeding. Open a console ( if you're using X-windows / KDE / Gnome / or whatever ) at the directory containing the files. Place a 3.5 inch HD floppy in fd0, and ENTER at the prompt:   ./install.s
( make sure to 'umount' any previous floppy diskette, but do not mount this one! If there's a problem, read section "4) GNU/Linux installation" and following of the file, " tomsrtbt.FAQ " ).

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    The 1722 KiB (about 1.68 MiB) diskette (also incorrectly called a 1.72 or 1.722 mb following the usage of "1.44 mb" for 3.5 inch - 1440 KiB diskettes!) has a total of 3,444 sectors and a capacity of about 19.6% more than a 1440 kb floppy disk.

      So what is it about this diskette that might cause a problem in some floppy drives? Well, instead of using only 80 tracks (concentric rings of magnetic data) like a 1440 kb diskette, this one uses 82 tracks. Since the spacing between these tracks is the same for both diskettes, the drive heads must move a bit closer towards the center of the media to read tracks 81 and 82. If a drive has some kind of physical 'stop' that won't allow the heads to travel far enough (or possibly a controller chip telling the PC it can't seek higher than 81 tracks), then there'd be a problem! As we said above though, almost any drive being sold today should be able to handle 82-track and even 83-track diskettes without any problems ( I have to wonder if it's because these drives don't have any 'stops' at all).

    But simply adding two extra tracks would yield just another 72 sectors (that's 18 sectors per track x 4; remember there are 2 sides). In order to get 564 more sectors (3,444 - 2,880) onto a 3.5 inch diskette, the number of sectors per track must be increased to 21 (apparently the limit for MS-DOS compatibility). So, the total capacity of a 1722 kb diskette can now be computed as follows:

21 sectors/track x 82 tracks/side x 2 sides = 3,444 sectors.
512 bytes/sector x 3,444 sectors = 1,763,328 bytes.
1,763,328 bytes ÷ 1024 bytes/KiB = 1722 KiB
1,763,328 bytes ÷ 1,048,576 bytes/MiB = 1.681640625 MiB

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Last Updated: 26 AUG 2002.