On Sun, Dec 11, 2005 at 07:17:43PM +0000, David Laight wrote:
> 
> Looks like (somehow) sector 0 doesn't contain code that the BIOS deems
> valid - although there are no well defined checks it can do.
> (The 'Not a system disk' output if you put a floppy in, is actually from
> the boot code on the floppy!)

ISTR that indeed the check is about the signature at the end of the boot
block (0xAA55) [little endian so appears as 0x55 0xAA]. That is the
previous stage trying to chain load another stage 1 (512 bytes) that
shall do the test. So the "Not a system disk" comes from the BIOS if the
signature is missing. AFAIK, if it is present it will load the block and
give it the control even if the block is just junk.

Cheers,
-- 
Thierry Laronde (Alceste) <tlaronde +AT+ polynum +dot+ com>
                 http://www.kergis.com/
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