Bootable Floppy from CD?

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Thu May 25 03:18:05 2000

On May 24, 17:45, Chuck McManis wrote:
> In an effort to preserve all my miscellaneous driver floppies I've been
> copying them to CD-rom. I figured I should also do this for my DOS 6.3
> disks but realized that I don't know how to create a bootable DOS 6.3
> system disk from the disk itself. I've considered using dd(1) on unix to
> create just the disk image that I can later use dd to copy back out but
> was wondering if perhaps there was a better way.

As Roger pointed out, you're better to keep a boot floppy (or several
varieties) -- it's more reliable. Bootable CDs require BIOS support which
not all BIOSes have.

On May 25, 0:56, Eric Smith wrote:
> What I use on Linux to back up images of 1440K floppies is:
> dd if=/dev/fd0 of=floppy.img bs=18k
[...]
> There's a DOS program called "rawrite" that can recreate floppies

All true, and Chuck may find it useful to have several floppy images on a
CD, but that won't make the CD bootable.

An IDE CDROM doesn't look the same as an IDE hardrive, as far as the BIOS
is concerned, so 'dd' from a bootable harddrive won't work.

On Wed, 24 May 2000, Richard Erlacher wrote:
> don't know what the appropriate spec for a bootable CD would be. I do
> recall that ISO9660 or whatever it was is NOT the right format.

If you want a bootable CD for a PC, you *do* make it ISO 9660 format but
with an El Torito boot catalog addition (Carlos was right about the name).
 As far as I remember, what this actually does is make a CD that has an
image of a boot floppy embedded within it, but if you really want to know
how it works, look in Andy McFadden's CD-R FAQ, or check the standard at
 http://www.ptltd.com/techs/specs.html .

The "bootableness" isn't a function of DOS, by the way; it's a function of
the BIOS, and you would make a bootable Linux CD the same way.

On May 24, 20:47, Charles P. Hobbs (SoCalTip) wrote:
> "High Sierra"???

FYI, High Sierra is nothing to do with El Torito -- it's the name of the
format system used prior to the ISO 9660 standard, and from which the ISO
standard was derived.

-- 
Pete						Peter Turnbull
						Dept. of Computer Science
						University of York
Received on Thu May 25 2000 - 03:18:05 BST

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