<s>
Dynamic	B-Device
drive	I-Device
overlay	I-Device
(	O
DDO	O
,	O
also	O
referred	O
to	O
as	O
:	O
software	O
translation	O
driver	O
)	O
is	O
a	O
software	O
technique	O
to	O
extend	O
a	O
system	B-Operating_System
BIOS	I-Operating_System
that	O
does	O
not	O
support	O
logical	B-Device
block	I-Device
addressing	I-Device
(	O
LBA	O
)	O
to	O
access	O
drives	O
larger	O
than	O
504	O
MiB	O
.	O
</s>
<s>
This	O
technique	O
overrides	O
some	O
of	O
the	O
motherboard	B-Device
BIOS	B-Operating_System
 '	O
hard	O
disk	O
controller	O
driver	O
in	O
RAM	B-Architecture
.	O
</s>
<s>
To	O
ensure	O
that	O
this	O
extension	O
gets	O
loaded	O
early	O
most	O
often	O
the	O
boot	B-Operating_System
disk	I-Operating_System
's	O
master	O
boot	O
record	O
is	O
modified	O
and	O
the	O
software	O
installed	O
at	O
the	O
beginning	O
of	O
the	O
disk	O
.	O
</s>
<s>
The	O
application	O
of	O
a	O
Dynamic	B-Device
Drive	I-Device
Overlay	I-Device
(	O
DDO	O
)	O
,	O
as	O
licensed	O
to	O
Samsung	O
Corporation	O
for	O
example	O
,	O
by	O
Kroll	O
Ontrack	O
's	O
version	O
in	O
their	O
Disk	O
Manager	O
program	O
is	O
for	O
the	O
installation	O
of	O
various	O
hard	O
drives	O
(	O
Ultra/Super	O
IDE/Parallel	O
ATA	O
)	O
in	O
computers	O
that	O
have	O
older	O
BIOS	B-Operating_System
chips	I-Operating_System
that	O
do	O
not	O
recognize	O
hard	O
disk	O
drives	O
larger	O
than	O
137.4	O
Gigabytes	O
.	O
</s>
<s>
The	O
interface	O
is	O
a	O
software	O
program	O
that	O
is	O
loaded	O
at	O
start-up	O
by	O
the	O
computer	O
and	O
augments	O
the	O
BIOS	B-Operating_System
code	O
,	O
thus	O
allowing	O
the	O
system	O
to	O
recognize	O
and	O
read	O
areas	O
of	O
the	O
hard	O
disk	O
drive	O
that	O
normally	O
would	O
not	O
be	O
accessible	O
by	O
the	O
older	O
BIOS	B-Operating_System
.	O
</s>
