<s>
IBMDOS.COM	O
is	O
the	O
filename	O
of	O
the	O
DOS	B-Device
kernel	B-Operating_System
.	O
</s>
<s>
Loaded	O
and	O
initially	O
invoked	O
by	O
the	O
DOS	B-Device
BIOS	O
in	O
IBMBIO.COM	O
during	O
the	O
boot	O
process	O
,	O
it	O
contains	O
the	O
hardware-independent	O
parts	O
of	O
the	O
operating	O
system	O
,	O
including	O
the	O
embedded	O
FAT12	B-Application
,	O
FAT16	B-Application
and	O
,	O
in	O
newer	O
versions	O
,	O
the	O
FAT32	B-Application
file	B-Application
system	I-Application
code	O
,	O
as	O
well	O
as	O
the	O
code	O
to	O
provide	O
the	O
DOS	B-Application
API	I-Application
to	O
applications	O
.	O
</s>
<s>
The	O
file	O
exists	O
in	O
PC	B-Operating_System
DOS	I-Operating_System
1.0	O
to	O
7.10	O
and	O
DR	O
DOS	B-Device
5.0	O
and	O
higher	O
(	O
except	O
for	O
DR-DOS	O
7.06	O
)	O
,	O
with	O
MS-DOS	B-Application
using	O
MSDOS.SYS	O
(	O
from	O
version	O
1.10	O
to	O
6.22	O
)	O
for	O
the	O
same	O
purpose	O
.	O
</s>
<s>
(	O
For	O
compatibility	O
purposes	O
with	O
some	O
DOS	B-Device
applications	O
the	O
IBMDOS.COM	O
file	O
name	O
was	O
briefly	O
also	O
used	O
by	O
the	O
IBM	O
version	O
of	O
OS/2	O
1.0	O
,	O
where	O
it	O
resembled	O
the	O
OS2DOS.COM	B-Device
OS/2	O
kernel	B-Operating_System
file	O
as	O
used	O
by	O
Microsoft	O
.	O
)	O
</s>
<s>
By	O
default	O
,	O
the	O
file	O
is	O
located	O
in	O
the	O
root	B-Application
directory	I-Application
of	O
the	O
bootable	O
drive/partition	O
(	O
normally	O
C:\	O
)	O
and	O
has	O
the	O
hidden	O
,	O
read-only	O
,	O
and	O
system	O
file	B-Application
attributes	I-Application
set	O
.	O
</s>
<s>
This	O
is	O
not	O
necessary	O
for	O
DR-DOS	O
7.02	O
and	O
higher	O
,	O
because	O
under	O
these	O
systems	O
the	O
file	O
is	O
a	O
fat	B-Application
binary	O
also	O
containing	O
a	O
tiny	O
COM-style	O
stub	O
just	O
displaying	O
some	O
version	O
info	O
and	O
exiting	O
gracefully	O
when	O
loaded	O
inappropriately	O
.	O
</s>
<s>
In	O
Digital	O
Research	O
terminology	O
,	O
the	O
kernel	B-Operating_System
component	O
of	O
the	O
operating	O
system	O
is	O
called	O
the	O
BDOS	O
(	O
Basic	B-Operating_System
Disk	I-Operating_System
Operating	I-Operating_System
System	I-Operating_System
)	O
,	O
a	O
term	O
originally	O
coined	O
by	O
Gary	O
Kildall	O
in	O
1975	O
for	O
CP/M	O
,	O
but	O
which	O
is	O
continued	O
to	O
be	O
used	O
in	O
all	O
other	O
DRI	O
operating	O
systems	O
(	O
except	O
for	O
Concurrent	B-Operating_System
DOS	I-Operating_System
286	I-Operating_System
and	O
FlexOS	B-Operating_System
)	O
.	O
</s>
<s>
Microsoft	O
has	O
used	O
this	O
name	O
as	O
well	O
when	O
referring	O
to	O
the	O
kernel	B-Operating_System
of	O
the	O
MSX-DOS	B-Operating_System
operating	O
system	O
.	O
</s>
<s>
The	O
FAT	B-Application
file	I-Application
system	I-Application
specific	O
code	O
is	O
called	O
the	O
FDOS	O
in	O
DRI	O
terminology	O
.	O
</s>
