[syslinux] Re: Trying to figure out why my Cruzer Micro 512"MB" won't boot.

Nazo nazosan at gmail.com
Tue May 2 08:33:39 PDT 2006

The HP tool, so far as I know, essentially makes it USB-HDD
architecture with no changes to geometry/etc (I think, I'm not sure
about this part.)  It definitely does not do anything like the USB-ZIP

Anyway, the real reason I'm replying now is to say that I have
discovered some of the systems in my school actually don't have a
password on the BIOS, but, simply appeared to be.  I tested the option
to boot the flashdrive, and as nearly as I can tell they sucessfully
booted it as USB-HDD (I'm sorry, these are the only test systems I
have, and I can't be 100% sure, but, the BIOS did act like it was a
harddrive -- in fact, it didn't say "USB Harddrive" or anything like
that, but, actually showed "Cruzer Micro" in the list of harddrives to
boot.)  I'm 99% sure that it did boot as USB-HDD despite the
uncertainty involved here.  Really, I always thought it made sense
that it should though.  I mean, a ZIP disk does follow the basic
standards for a harddrive, it just adds that one little signature
peice of weirdness with the only partition being the last primary for
some reason (makes me wonder if they intended for you to be able to
place another primary partition or something for hidden data or
perhaps for extra diagnostic utilities or something.  I have a grand
total of 0 zip disks or drives available to actually test such a
theory on.)

Actually, I have a request.  I think that this means it is 100% safe
to use the USB-ZIP trick, and if so, I think that it should be
generally recommended that people use that method while their drives
are still clean after buying -- before it can get to be troublesome to
change things.  Obviously this is no good if it is not true though. 
Does anyone else have a BIOS which supports booting USB-HDD and a
little time?  If so, could you be kind enough to test your flashdrive
with the mkdiskimage fake ZIP drive trick and see if the BIOS will
sucessfully boot in USB-HDD mode?  IMO, if they all work like this,
there is no reason not to just go straight to USB-ZIP for maximum
compatibilitie (after all, you never know when you may need to use it
on a system which does not support USB-HDD, such as maybe a friend's
computer or something.)

On 4/27/06, Josh Lehan <jlehan at scyld.com> wrote:
> Nazo wrote:
> > Actually, I had a real purpose for replying, not just to say that.  I
> > actually would like to ask for anyone who might know if they can tell
> > me if a flashdrive emulating USB-ZIP can be booted under USB-HDD mode.
> I believe that it can.  USB-ZIP is simply USB-HDD with stricter
> requirements, I believe.
> USB-HDD + use of partition #4 + use of */64/32 geometry = USB-ZIP.
> For partition order, it should not matter what one of the 4 partitions
> in the MBR you use, as long as only one is marked as active.
> Most MBR assembly code I've seen just scans down the table of 4
> partitions, in order, and honor the first one that has the active byte
> set to 0x80.  The other 3 partitions should have their active bytes set
> to 0x00.
> The other USB-ZIP requirement is */64/32 CHS geometry.  End your
> partition on a full cylinder boundary, so that the ending sector CHS
> head and sector numbers are maxed out.
> The HP formatter tool doesn't have an option to enable USB-ZIP,
> surprisingly.  Might try to merge them somehow, perhaps using the HP
> formatter first on a blank USB key, and then editing the partition table
> to force it into USB-ZIP compliance, and then see if you have success.
> Josh

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