Pascal Hambourg <pas...@plouf.fr.eu.org> writes:
> Le 06/05/2017 ? 05:59, Felix Miata a ?crit :
>
>
> The primary purpose of a boot flag is to be found by
> DOS/Windows/legacy-compatible MBR code, which can only make use of it
> if found
> on a primary partition that also contains a bootable filesystem or
> other
> bootloader code in the partition's PBR.
>
> A secondary purpose of a boot flag is for legacy operating systems to
> determine
> which primary partition is to be assigned a drive letter.
>
>
>
> Another purpose of a boot flag is to allow booting with broken BIOS which
> require that the boot disk has a partition table which defines a primary
> partition with the boot flag.
>
>
>
Thank you to everybody who has responded. I made some
more changes to the now working drive so I used dd to make
another copy. This time, I also added a bs=1000000 directive to the dd
command using 1-million bytes in each transfer rather than using
the default of 512 bytes. the source and target drives share the
same controller with the source drive being the second connector on
the ribbon cable.
After the much, much quicker copy, I removed the source
drive, changed the jumper to make it the boot master again and
put it back on the Optoplex. This time, there was no change in
the ability to boot so I am not sure what happened before as it
booted right up again.
I am thinking the BIOS has bugs in it and will get the service
tag. I am now reaping the whirlwind of putting it on a platform
about 60 CM below the ceiling where the rear panel is facing a
wall in a corner. Getting it down without dropping it is
Olympic-level gymnastics but I did it. I even got it back in it's
normal place about 23 CM or 9 inches below the ceiling, just
enough room to close the case without scraping the ceiling:
Serial Number: ON2TY
Model Number: DCM
Reference Number: 98054
BIOS Information
Vendor: Dell Computer Corporation
Version: A09
Release Date: 07/12/00
Address: 0xF0000
Runtime Size: 64 kB
ROM Size: 256 kB
Characteristics:
ISA is supported
PCI is supported
PNP is supported
APM is supported
BIOS is upgradeable
BIOS shadowing is allowed
ESCD support is available
Boot from CD is supported
Selectable boot is supported
EDD is supported
Japanese floppy for Toshiba 1.2 MB is supported (int 13h)
5.25"/360 kB floppy services are supported (int 13h)
5.25"/1.2 MB floppy services are supported (int 13h)
3.5"/720 kB floppy services are supported (int 13h)
3.5"/2.88 MB floppy services are supported (int 13h)
Print screen service is supported (int 5h)
8042 keyboard services are supported (int 9h)
Serial services are supported (int 14h)
Printer services are supported (int 17h)
CGA/mono video services are supported (int 10h)
AGP is supported
LS-120 boot is supported
ATAPI Zip drive boot is supported
