<s>
DR-DOS	O
(	O
written	O
as	O
DR	O
DOS	B-Device
,	O
without	O
a	O
hyphen	O
,	O
in	O
versions	O
up	O
to	O
and	O
including	O
6.0	O
)	O
is	O
a	O
disk	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
for	B-Language
IBM	B-Device
PC	I-Device
compatibles	O
.	O
</s>
<s>
Upon	O
its	O
introduction	O
in	O
1988	O
,	O
it	O
was	O
the	O
first	O
DOS	B-Device
attempting	O
to	O
be	O
compatible	O
with	O
IBM	B-Operating_System
PC	I-Operating_System
DOS	I-Operating_System
and	O
MS-DOS	B-Application
(	O
which	O
were	O
the	O
same	O
product	O
sold	O
under	O
different	O
names	O
)	O
.	O
</s>
<s>
DR-DOS	O
was	O
developed	O
by	O
Gary	O
A	O
.	O
Kildall	O
's	O
Digital	O
Research	O
and	O
derived	O
from	O
Concurrent	O
PC	O
DOS	B-Device
6.0	O
,	O
which	O
was	O
an	O
advanced	O
successor	O
of	O
CP/M	B-Operating_System
-86	I-Operating_System
.	O
</s>
<s>
As	O
ownership	O
changed	O
,	O
various	O
later	O
versions	O
were	O
produced	O
with	O
names	O
including	O
Novell	B-Operating_System
DOS	I-Operating_System
and	O
Caldera	O
OpenDOS	O
.	O
</s>
<s>
Digital	O
Research	O
's	O
original	O
CP/M	B-Application
for	B-Language
the	O
8-bit	O
Intel	B-General_Concept
8080	I-General_Concept
-	O
and	O
Z-80-based	O
systems	O
spawned	O
numerous	O
spin-off	O
versions	O
,	O
most	O
notably	O
CP/M	B-Operating_System
-86	I-Operating_System
for	B-Language
the	O
Intel	O
8086/8088	O
family	O
of	O
processors	O
.	O
</s>
<s>
Although	O
CP/M	B-Application
had	O
dominated	O
the	O
market	O
since	O
the	O
mid-1970s	O
,	O
and	O
was	O
shipped	O
with	O
the	O
vast	O
majority	O
of	O
non-proprietary-architecture	O
personal	O
computers	O
,	O
the	O
IBM	B-Device
PC	I-Device
in	O
1981	O
brought	O
the	O
beginning	O
of	O
what	O
was	O
eventually	O
to	O
be	O
a	O
massive	O
change	O
.	O
</s>
<s>
IBM	O
originally	O
approached	O
Digital	O
Research	O
in	O
1980	O
,	O
seeking	O
an	O
x86	B-Operating_System
version	O
of	O
CP/M	B-Application
.	O
</s>
<s>
Instead	O
,	O
a	O
deal	O
was	O
struck	O
with	O
Microsoft	O
,	O
who	O
purchased	O
another	O
operating	O
system	O
,	O
86-DOS	B-Operating_System
,	O
from	O
Seattle	O
Computer	O
Products	O
(	O
SCP	O
)	O
.	O
</s>
<s>
This	O
became	O
Microsoft	B-Application
MS-DOS	I-Application
and	O
IBM	B-Device
PC	I-Device
DOS	B-Device
.	O
</s>
<s>
86-DOS	B-Operating_System
'	O
s	O
command	B-Operating_System
structure	O
and	O
application	B-Application
programming	I-Application
interface	I-Application
imitated	O
that	O
of	O
CP/M	B-Application
2.2	O
(	O
with	O
BDOS	B-Operating_System
2.2	O
)	O
.	O
</s>
<s>
Digital	O
Research	O
threatened	O
legal	O
action	O
,	O
claiming	O
PCDOS/MS	O
-DOS	O
to	O
be	O
too	O
similar	O
to	O
CP/M	B-Application
.	O
</s>
<s>
In	O
early	O
1982	O
,	O
IBM	O
settled	O
by	O
agreeing	O
to	O
sell	O
Digital	O
Research	O
's	O
x86	B-Operating_System
version	O
of	O
CP/M	B-Application
,	O
CP/M	B-Operating_System
-86	I-Operating_System
,	O
alongside	O
PCDOS	B-Operating_System
.	O
</s>
<s>
However	O
,	O
PCDOS	B-Operating_System
sold	O
for	B-Language
while	O
CP/M	B-Operating_System
-86	I-Operating_System
had	O
a	O
$240	O
price	O
tag	O
.	O
</s>
<s>
The	O
proportion	O
of	O
PC	O
buyers	O
prepared	O
to	O
spend	O
six	O
times	O
as	O
much	O
to	O
buy	O
CP/M	B-Operating_System
-86	I-Operating_System
was	O
very	O
small	O
,	O
and	O
the	O
limited	O
availability	O
of	O
compatible	O
application	O
software	O
,	O
at	O
first	O
in	O
Digital	O
Research	O
's	O
favor	O
,	O
was	O
only	O
temporary	O
.	O
</s>
<s>
Digital	O
Research	O
fought	O
a	O
long	O
losing	O
battle	O
to	O
promote	O
CP/M	B-Operating_System
-86	I-Operating_System
and	O
its	O
multi-tasking	O
multi-user	O
successors	O
MP/M	B-Operating_System
-86	I-Operating_System
and	O
Concurrent	B-Operating_System
CP/M	I-Operating_System
-86	I-Operating_System
,	O
and	O
eventually	O
decided	O
that	O
they	O
could	O
not	O
beat	O
the	O
Microsoft-IBM	O
lead	O
in	O
application	O
software	O
availability	O
,	O
so	O
they	O
modified	O
Concurrent	B-Operating_System
CP/M	I-Operating_System
-86	I-Operating_System
to	O
allow	O
it	O
to	O
run	O
the	O
same	O
applications	O
as	O
MS-DOS	B-Application
and	O
PCDOS	B-Operating_System
.	O
</s>
<s>
This	O
was	O
shown	O
publicly	O
in	O
December	O
1983	O
and	O
shipped	O
in	O
March	O
1984	O
as	O
Concurrent	O
DOS	B-Device
3.1	O
(	O
a.k.a.	O
</s>
<s>
CDOS	O
with	O
BDOS	B-Operating_System
3.1	O
)	O
to	O
hardware	O
vendors	O
.	O
</s>
<s>
While	O
Concurrent	O
DOS	B-Device
continued	O
to	O
evolve	O
in	O
various	O
flavours	O
over	O
the	O
years	O
to	O
eventually	O
become	O
Multiuser	B-Operating_System
DOS	I-Operating_System
and	O
REAL/32	B-Operating_System
,	O
it	O
was	O
not	O
specifically	O
tailored	O
for	B-Language
the	O
desktop	O
market	O
and	O
too	O
expensive	O
for	B-Language
single-user	O
applications	O
.	O
</s>
<s>
Therefore	O
,	O
over	O
time	B-Device
two	O
attempts	O
were	O
made	O
to	O
sideline	O
the	O
product	O
:	O
</s>
<s>
In	O
1985	O
,	O
Digital	O
Research	O
developed	O
DOS	B-Device
Plus	O
1.0	O
to	O
2.1	O
,	O
a	O
stripped-down	O
and	O
modified	O
single-user	O
derivative	O
of	O
Concurrent	O
DOS	B-Device
4.1	O
and	O
5.0	O
,	O
which	O
ran	O
applications	O
for	B-Language
both	O
platforms	O
,	O
and	O
allowed	O
switching	O
between	O
several	O
tasks	O
as	O
did	O
the	O
original	O
CP/M	B-Operating_System
-86	I-Operating_System
.	O
</s>
<s>
Its	O
DOS	B-Device
compatibility	O
was	O
limited	O
,	O
and	O
Digital	O
Research	O
made	O
another	O
attempt	O
,	O
this	O
time	B-Device
a	O
native	O
DOS	B-Device
system	O
.	O
</s>
<s>
This	O
new	O
disk	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
was	O
launched	O
in	O
1988	O
as	O
DRDOS	O
.	O
</s>
<s>
Although	O
DRI	O
was	O
based	O
in	O
Pacific	O
Grove	O
and	O
later	O
in	O
Monterey	O
,	O
California	O
,	O
USA	O
,	O
the	O
work	O
on	O
DOSPlus	B-Operating_System
started	O
in	O
Newbury	O
,	O
Berkshire	O
in	O
the	O
UK	O
,	O
where	O
Digital	O
Research	O
Europe	O
had	O
its	O
OEM	O
Support	O
Group	O
located	O
since	O
1983	O
.	O
</s>
<s>
Beginning	O
in	O
1986	O
,	O
most	O
of	O
the	O
operating	O
system	O
work	O
on	O
Concurrent	B-Operating_System
DOS	I-Operating_System
386	I-Operating_System
and	O
XM	B-Operating_System
,	O
Multiuser	B-Operating_System
DOS	I-Operating_System
,	O
DRDOS	O
and	O
PalmDOS	O
was	O
done	O
in	O
Digital	O
Research	O
's	O
European	O
Development	O
Centre	O
(	O
EDC	O
)	O
in	O
Hungerford	O
,	O
Berkshire	O
.	O
</s>
<s>
As	O
requested	O
by	O
several	O
OEMs	O
,	O
Digital	O
Research	O
started	O
a	O
plan	O
to	O
develop	O
a	O
new	O
DOS	B-Device
operating	O
system	O
addressing	O
the	O
defects	O
left	O
by	O
MS-DOS	B-Application
in	O
1987	O
.	O
</s>
<s>
Of	O
particular	O
importance	O
was	O
a	O
million	O
dollar	O
deal	O
with	O
Kazuhiko	O
"	O
Kay	O
"	O
Nishi	O
of	O
ASCII	O
Corporation	O
,	O
who	O
had	O
previously	O
been	O
instrumental	O
in	O
opening	O
the	O
Japanese	O
OEM	O
market	O
for	B-Language
Microsoft	O
.	O
</s>
<s>
Version	O
numbers	O
were	O
chosen	O
to	O
reflect	O
features	O
relative	O
to	O
MS-DOS	B-Application
;	O
the	O
first	O
version	O
promoted	O
to	O
the	O
public	O
was	O
DRDOS	O
3.31	O
,	O
which	O
offered	O
features	O
comparable	O
to	O
Compaq	O
MS-DOS	B-Application
3.31	O
with	O
large	O
disk	O
support	O
(	O
FAT16B	B-Application
a.k.a.	O
</s>
<s>
DRDOS	O
3.31	O
reported	O
itself	O
as	O
"	O
IBM	O
PCDOS	B-Operating_System
3.31	O
"	O
,	O
while	O
the	O
internal	O
BDOS	B-Operating_System
(	O
Basic	B-Operating_System
Disk	I-Operating_System
Operating	I-Operating_System
System	I-Operating_System
)	O
kernel	O
version	O
was	O
reported	O
as	O
6.0	O
,	O
single-user	O
nature	O
,	O
reflecting	O
its	O
origin	O
as	O
derivative	O
of	O
Concurrent	O
DOS	B-Device
6.0	O
with	O
the	O
multitasking	O
and	O
multiuser	O
capabilities	O
as	O
well	O
as	O
CP/M	B-Application
API	B-Application
support	O
stripped	O
out	O
and	O
the	O
XIOS	B-Architecture
replaced	O
by	O
an	O
IBM-compatible	O
DOS-BIOS	O
.	O
</s>
<s>
The	O
system	O
files	O
were	O
named	O
DRBIOS.SYS	O
(	O
for	B-Language
the	O
DOS-BIOS	O
)	O
and	O
DRBDOS.SYS	O
(	O
for	B-Language
the	O
BDOS	B-Operating_System
kernel	O
)	O
,	O
the	O
disk	O
OEM	O
label	B-Device
used	O
was	O
"	O
DIGITAL␠	O
"	O
.	O
</s>
<s>
DRDOS	O
offered	O
some	O
extended	O
command	B-Application
line	I-Application
tools	I-Application
with	O
command	B-Application
line	I-Application
help	O
,	O
verbose	O
error	B-Device
messages	O
,	O
sophisticated	O
command	B-Application
line	I-Application
history	I-Application
and	O
editing	O
(	O
HISTORY	B-Device
directive	O
)	O
as	O
well	O
as	O
support	O
for	B-Language
file	O
and	O
directory	O
passwords	O
built	O
right	O
into	O
the	O
kernel	O
.	O
</s>
<s>
It	O
was	O
also	O
cheaper	O
to	O
license	B-License
than	O
MS-DOS	B-Application
,	O
and	O
was	O
ROMable	O
right	O
from	O
the	O
start	O
.	O
</s>
<s>
DRI	O
was	O
approached	O
by	O
a	O
number	O
of	O
PC	O
manufacturers	O
who	O
were	O
interested	O
in	O
a	O
third-party	O
DOS	B-Device
,	O
which	O
prompted	O
several	O
updates	O
to	O
the	O
system	O
.	O
</s>
<s>
At	O
this	O
time	B-Device
,	O
MS-DOS	B-Application
was	O
only	O
available	O
to	O
OEMs	O
bundled	O
with	O
hardware	O
.	O
</s>
<s>
Consequently	O
,	O
DRDOS	O
achieved	O
some	O
immediate	O
success	O
when	O
it	O
became	O
possible	O
for	B-Language
consumers	O
to	O
buy	O
it	O
through	O
normal	O
retail	O
channels	O
beginning	O
with	O
version	O
3.4x	O
.	O
</s>
<s>
Known	O
versions	O
are	O
DRDOS	O
3.31	O
(	O
BDOS	B-Operating_System
6.0	O
,	O
June	O
1988	O
,	O
OEM	O
only	O
)	O
,	O
3.32	O
(	O
BDOS	B-Operating_System
6.0	O
,	O
17	O
August	O
1988	O
,	O
OEM	O
only	O
)	O
,	O
3.33	O
(	O
BDOS	B-Operating_System
6.0	O
,	O
1	O
September	O
1988	O
,	O
OEM	O
only	O
)	O
,	O
3.34	O
(	O
BDOS	B-Operating_System
6.0	O
,	O
OEM	O
only	O
)	O
,	O
3.35	O
(	O
BDOS	B-Operating_System
6.0	O
,	O
21	O
October	O
1988	O
,	O
OEM	O
only	O
)	O
,	O
3.40	O
(	O
BDOS	B-Operating_System
6.0	O
,	O
25	O
January	O
1989	O
)	O
,	O
3.41	O
(	O
BDOS	B-Operating_System
6.3	O
,	O
June	O
1989	O
,	O
OEM	O
and	O
retail	O
)	O
.	O
</s>
<s>
Like	O
MS-DOS	B-Application
,	O
most	O
of	O
them	O
were	O
produced	O
in	O
several	O
variants	O
for	B-Language
different	O
hardware	O
.	O
</s>
<s>
While	O
most	O
OEMs	O
kept	O
the	O
DRDOS	O
name	O
designation	O
,	O
2001Sales	O
,	O
Inc	O
.	O
marketed	O
it	O
under	O
the	O
name	O
EZ-DOS	O
3.41	O
(	O
also	O
known	O
as	O
EZ-DOS	O
4.1	O
)	O
.	O
</s>
<s>
DRDOS	O
version	O
5.0	O
(	O
code-named	O
"	O
Leopard	O
"	O
)	O
was	O
released	O
in	O
May	O
1990	O
,	O
still	O
reporting	O
itself	O
as	O
"	O
PCDOS	B-Operating_System
3.31	O
"	O
for	B-Language
compatibility	O
purposes	O
,	O
but	O
internally	O
indicating	O
a	O
single-user	O
BDOS	B-Operating_System
6.4	O
kernel	O
.	O
</s>
<s>
(	O
Version	O
4	O
was	O
skipped	O
to	O
avoid	O
being	O
associated	O
with	O
the	O
relatively	O
unpopular	O
MS-DOS	B-Application
4.0	I-Application
.	O
)	O
</s>
<s>
This	O
introduced	O
ViewMAX	B-Application
,	O
a	O
GEM-based	O
GUI	B-Application
file	O
management	O
shell	O
.	O
</s>
<s>
ViewMAX	B-Application
's	O
startup	O
screen	O
would	O
present	O
the	O
slogan	O
"	O
Digital	O
Research	O
-	O
We	O
make	O
computers	O
work	O
"	O
.	O
</s>
<s>
DRDOS	O
5.0	O
also	O
introduced	O
the	O
patented	O
BatteryMAX	O
power	O
management	O
system	O
,	O
bundled	O
disk-caching	O
software	O
(	O
DRCACHE	O
)	O
,	O
a	O
remote	O
file	B-Protocol
transfer	I-Protocol
tool	O
(	O
FILELINK	O
)	O
,	O
a	O
cursor	O
shape	O
configuration	O
utility	O
(	O
CURSOR	O
)	O
,	O
and	O
offered	O
a	O
vastly	O
improved	O
memory	O
management	O
system	O
(	O
MemoryMAX	O
)	O
.	O
</s>
<s>
For	B-Language
compatibility	O
purposes	O
,	O
the	O
DRDOS	O
5.0	O
system	O
files	O
were	O
now	O
named	O
IBMBIO.COM	O
(	O
for	B-Language
the	O
DOS-BIOS	O
)	O
and	O
IBMDOS.COM	O
(	O
for	B-Language
the	O
BDOS	B-Operating_System
kernel	O
)	O
and	O
due	O
to	O
the	O
advanced	O
loader	O
in	O
the	O
boot	B-Device
sector	I-Device
could	O
be	O
physically	O
stored	O
anywhere	O
on	O
disk	O
.	O
</s>
<s>
The	O
OEM	O
label	B-Device
in	O
the	O
boot	B-Device
sectors	I-Device
was	O
changed	O
to	O
"	O
IBM␠␠	O
3.3	O
"	O
.	O
</s>
<s>
DRDOS	O
5.0	O
was	O
the	O
first	O
DOS	B-Device
to	O
include	O
load-high	O
capabilities	O
.	O
</s>
<s>
The	O
kernel	O
and	O
data	O
structures	O
such	O
as	O
disk	O
buffers	O
could	O
be	O
relocated	O
in	O
the	O
High	B-Device
Memory	I-Device
Area	I-Device
(	O
HMA	B-Device
)	O
,	O
the	O
first	O
64KB	O
of	O
extended	B-Device
memory	I-Device
which	O
are	O
accessible	O
in	O
real	B-Application
mode	I-Application
.	O
</s>
<s>
This	O
freed	O
up	O
the	O
equivalent	O
amount	O
of	O
critical	O
"	O
base	O
"	O
or	O
conventional	B-Device
memory	I-Device
,	O
the	O
first	O
640KB	O
of	O
the	O
PC	O
's	O
RAM	O
–	O
the	O
area	O
in	O
which	O
all	O
DOS	B-Device
applications	O
run	O
.	O
</s>
<s>
Additionally	O
,	O
on	O
Intel	B-General_Concept
80386	I-General_Concept
machines	O
,	O
DRDOS	O
's	O
EMS	O
memory	O
manager	O
allowed	O
the	O
operating	O
system	O
to	O
load	O
DOS	B-Device
device	O
drivers	O
into	O
upper	B-Device
memory	I-Device
blocks	I-Device
,	O
further	O
freeing	O
base	B-Device
memory	I-Device
.	O
</s>
<s>
DRDOS	O
5.0	O
was	O
the	O
first	O
DOS	B-Device
to	O
integrate	O
such	O
functionality	O
into	O
the	O
base	O
OS	O
(	O
loading	O
device	O
drivers	O
into	O
upper	B-Device
memory	I-Device
blocks	I-Device
was	O
already	O
possible	O
using	O
third-party	O
software	O
like	O
QEMM	B-Device
)	O
.	O
</s>
<s>
This	O
allowed	O
it	O
,	O
on	O
286	B-General_Concept
systems	O
with	O
supported	O
chipsets	O
and	O
on	O
386	B-General_Concept
systems	O
,	O
to	O
provide	O
significantly	O
more	B-Device
free	O
conventional	B-Device
memory	I-Device
than	O
any	O
other	O
DOS	B-Device
.	O
</s>
<s>
Once	O
drivers	O
for	B-Language
a	O
mouse	O
,	O
multimedia	O
hardware	O
and	O
a	O
network	O
stack	O
were	O
loaded	O
,	O
an	O
MS-DOS/PCDOS	O
machine	O
typically	O
might	O
only	O
have	O
had	O
300	O
to	O
400KB	O
of	O
free	O
conventional	B-Device
memory	I-Device
–	O
too	O
little	O
to	O
run	O
much	O
late-1980s	O
software	O
.	O
</s>
<s>
In	O
contrast	O
to	O
this	O
,	O
DRDOS	O
5.0	O
,	O
with	O
a	O
little	O
manual	O
tweaking	O
,	O
could	O
load	O
all	O
this	O
and	O
still	O
keep	O
all	O
of	O
its	O
conventional	B-Device
memory	I-Device
free	O
–	O
allowing	O
for	B-Language
some	O
necessary	O
DOS	B-Device
data	O
structures	O
,	O
as	O
much	O
as	O
620KB	O
out	O
of	O
the	O
640KB	O
.	O
</s>
<s>
With	O
MEMMAX+V	O
,	O
the	O
conventional	B-Device
memory	I-Device
region	O
could	O
even	O
be	O
extended	O
into	O
unused	O
portions	O
of	O
the	O
graphics	O
adapter	O
card	O
typically	O
providing	O
another	O
64	O
to	O
96KB	O
more	B-Device
free	B-Application
DOS	I-Application
memory	O
.	O
</s>
<s>
Because	O
DRDOS	O
left	O
so	O
much	O
conventional	B-Device
memory	I-Device
available	O
,	O
some	O
old	O
programs	O
utilizing	O
certain	O
address	O
wrapping	O
techniques	O
failed	O
to	O
run	O
properly	O
as	O
they	O
were	O
now	O
loaded	O
unexpectedly	O
(	O
or	O
,	O
under	O
MS-DOS	B-Application
,	O
"	O
impossibly	O
"	O
)	O
low	O
in	O
memory	O
–	O
inside	O
the	O
first	O
64KB	O
segment	O
(	O
known	O
as	O
"	O
low	B-Device
memory	I-Device
"	O
)	O
.	O
</s>
<s>
Therefore	O
,	O
DRDOS	O
5.0	O
'	O
s	O
new	O
MEMMAX-L	O
command	B-Operating_System
worked	O
around	O
this	O
by	O
pre-allocating	O
a	O
chunk	B-General_Concept
of	O
memory	O
at	O
the	O
start	O
of	O
the	O
memory	O
map	O
in	O
order	O
for	B-Language
programs	O
to	O
load	O
above	O
this	O
barrier	O
(	O
but	O
with	O
less	O
usable	O
conventional	B-Device
memory	I-Device
then	O
)	O
.	O
</s>
<s>
By	O
default	O
,	O
MEMMAX	O
was	O
configured	O
for	B-Language
+L	O
,	O
so	O
that	O
applications	O
could	O
take	O
advantage	O
of	O
the	O
extra	O
memory	O
.	O
</s>
<s>
Faced	O
with	O
substantial	O
competition	O
in	O
the	O
DOS	B-Device
arena	O
,	O
Microsoft	O
responded	O
with	O
an	O
announcement	O
of	O
a	O
yet-to-be	O
released	O
MS-DOS	B-Application
5.0	O
in	O
May	O
1990	O
.	O
</s>
<s>
DRDOS	O
6.0	O
,	O
while	O
already	O
at	O
BDOS	B-Operating_System
level	O
6.7	O
internally	O
,	O
would	O
still	O
report	O
itself	O
as	O
"	O
IBM	O
PCDOS	B-Operating_System
3.31	O
"	O
to	O
normal	O
DOS	B-Device
applications	O
for	B-Language
compatibility	O
purposes	O
.	O
</s>
<s>
DRDOS	O
6.0	O
also	O
included	O
a	O
task-switcher	O
named	O
TASKMAX	O
with	O
support	O
for	B-Language
the	O
industry-standard	O
task-switching	O
API	B-Application
to	O
run	O
multiple	O
applications	O
at	O
the	O
same	O
time	B-Device
.	O
</s>
<s>
In	O
contrast	O
to	O
Digital	O
Research	O
's	O
Multiuser	B-Operating_System
DOS	I-Operating_System
(	O
successor	O
of	O
Concurrent	O
DOS	B-Device
in	O
the	O
multi-user	O
products	O
line	O
)	O
,	O
which	O
would	O
run	O
DOS	B-Device
applications	O
in	O
pre-emptively	O
multitasked	O
virtual	O
DOS	B-Device
machines	O
,	O
the	O
DRDOS	O
6.0	O
task	O
switcher	O
would	O
freeze	O
background	O
applications	O
until	O
brought	O
back	O
into	O
the	O
foreground	O
.	O
</s>
<s>
While	O
it	O
ran	O
on	O
x86-machines	O
,	O
it	O
was	O
able	O
to	O
swap	O
to	O
XMS	B-Device
memory	I-Device
on	O
286+	O
machines	O
.	O
</s>
<s>
TASKMAX	O
did	O
support	O
some	O
Copy	B-General_Concept
&	I-General_Concept
Paste	I-General_Concept
facility	O
between	O
applications	O
.	O
</s>
<s>
Via	O
the	O
task-switcher	O
API	B-Application
,	O
graphical	B-Application
user	I-Application
interfaces	I-Application
such	O
as	O
ViewMAX	B-Application
or	O
PC/GEOS	B-Application
could	O
register	O
as	O
the	O
task	O
manager	O
menu	O
and	O
thereby	O
replace	B-Device
the	O
TASKMAX	O
text	O
mode	O
menu	O
,	O
so	O
that	O
users	O
could	O
switch	O
between	O
tasks	O
from	O
within	O
a	O
GUI	B-Application
.	O
</s>
<s>
Microsoft	O
responded	O
with	O
MS-DOS	B-Application
6.0	O
,	O
which	O
again	O
matched	O
some	O
features	O
of	O
DRDOS	O
6.0	O
.	O
</s>
<s>
In	O
December	O
1991	O
,	O
a	O
pre-release	O
version	O
of	O
Windows	B-Application
3.1	I-Application
was	O
found	O
to	O
return	O
a	O
non-fatal	O
error	B-Device
message	O
if	O
it	O
detected	O
a	O
non-Microsoft	O
DOS	O
.	O
</s>
<s>
It	O
was	O
a	O
simple	O
matter	O
for	B-Language
Digital	O
Research	O
to	O
patch	O
DRDOS	O
6.0	O
to	O
circumvent	O
the	O
AARD	O
code	O
'	O
authenticity	O
check	O
 '	O
in	O
the	O
Windows	B-Application
3.1	I-Application
beta	O
by	O
rearranging	O
the	O
order	O
of	O
two	O
internal	O
tables	O
in	O
memory	O
(	O
with	O
no	O
changes	O
in	O
functionality	O
)	O
,	O
and	O
the	O
patched	O
version	O
,	O
named	O
"	O
business	O
update	O
"	O
,	O
was	O
on	O
the	O
streets	O
within	O
six	O
weeks	O
of	O
the	O
release	O
of	O
Windows	B-Application
3.1	I-Application
.	O
</s>
<s>
With	O
the	O
detection	O
code	O
disabled	O
,	O
Windows	B-Application
ran	O
perfectly	O
under	O
DRDOS	O
and	O
its	O
successor	O
Novell	B-Operating_System
DOS	I-Operating_System
.	O
</s>
<s>
The	O
code	O
was	O
present	O
but	O
disabled	O
in	O
the	O
released	O
version	O
of	O
Windows	B-Application
3.1	I-Application
.	O
</s>
<s>
In	O
July	O
1992	O
,	O
Digital	O
Research	O
Japan	O
released	O
DRDOS	O
6.0/V	O
,	O
a	O
Japanese	O
DOS/V	B-Application
compatible	O
version	O
of	O
DRDOS	O
6.0	O
.	O
</s>
<s>
In	O
1992	O
Digital	O
Research	O
,	O
still	O
under	O
its	O
old	O
name	O
but	O
already	O
bought	O
by	O
Novell	O
in	O
July	O
1991	O
,	O
also	O
embarked	O
on	O
a	O
spin-off	O
product	O
code-named	O
"	O
Merlin	O
"	O
and	O
later	O
released	O
as	O
NetWare	B-Operating_System
PalmDOS	O
1	O
,	O
which	O
,	O
as	O
its	O
name	O
implies	O
,	O
was	O
a	O
very	O
resource-light	O
DRDOS	O
6.0	O
derivative	O
aimed	O
at	O
the	O
emerging	O
Palmtop/PDA	O
market	O
.	O
</s>
<s>
PalmDOS	O
was	O
the	O
first	O
operating	O
system	O
in	O
the	O
family	O
to	O
support	O
the	O
new	O
BDOS	B-Operating_System
7.0	O
kernel	O
with	O
native	O
DOS	B-Device
compatible	O
internal	O
data	O
structures	O
instead	O
of	O
emulations	O
thereof	O
.	O
</s>
<s>
Replacing	O
the	O
DOS	B-Device
emulation	O
on	O
top	O
of	O
a	O
CP/M	B-Application
kernel	O
by	O
a	O
true	O
DOS	B-Device
compatible	O
kernel	O
helped	O
a	O
lot	O
in	O
improving	O
compatibility	O
with	O
some	O
applications	O
using	O
some	O
of	O
DOS	B-Device
 '	O
internal	O
data	O
structures	O
and	O
also	O
was	O
the	O
key	O
in	O
reducing	O
the	O
resident	O
size	O
of	O
the	O
kernel	O
code	O
even	O
further	O
—	O
a	O
particular	O
requirement	O
for	B-Language
the	O
PDA	B-Application
market	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
introducing	O
a	O
genuine	O
Current	B-Application
Directory	I-Application
Structure	O
(	O
CDS	B-Application
)	O
imposed	O
a	O
limit	O
on	O
the	O
depth	O
of	O
working	B-Application
directories	I-Application
down	O
to	O
66	O
characters	O
(	O
as	O
in	O
MS-DOS/PCDOS	O
)	O
,	O
whereas	O
previous	O
issues	O
of	O
DRDOS	O
had	O
no	O
such	O
limitation	O
due	O
to	O
their	O
internal	O
organization	O
of	O
directories	O
as	O
relative	O
links	O
to	O
parent	O
directories	O
instead	O
of	O
as	O
absolute	O
paths	O
.	O
</s>
<s>
PalmDOS	O
still	O
reported	O
itself	O
as	O
"	O
PCDOS	B-Operating_System
3.31	O
"	O
to	O
applications	O
in	O
order	O
to	O
keep	O
the	O
kernel	O
small	O
and	O
not	O
run	O
into	O
compatibility	O
problems	O
with	O
Windows	B-Application
,	O
which	O
would	O
expect	O
the	O
DOSMGR	O
API	B-Application
to	O
be	O
implemented	O
for	B-Language
any	O
DOS	B-Device
version	O
since	O
5.0	O
.	O
</s>
<s>
As	O
well	O
as	O
a	O
ROM-executing	O
kernel	O
,	O
PalmDOS	O
had	O
palmtop-type	O
support	O
for	B-Language
features	O
such	O
as	O
PCMCIA	B-Architecture
PC	I-Architecture
Cards	I-Architecture
(	O
with	O
DPMS	O
support	O
)	O
,	O
power	O
management	O
(	O
BatteryMAX	O
and	O
the	O
device	O
driver	O
with	O
its	O
patented	O
dynamic	O
idle	O
detection	O
by	O
Gross	O
and	O
John	O
P	O
.	O
Constant	O
)	O
,	O
MINIMAX	B-Algorithm
task	O
switcher	O
support	O
for	B-Language
PIM	O
(	O
Personal	O
Information	O
Modules	O
)	O
applications	O
stored	O
and	O
executed	O
from	O
ROM	O
via	O
XIP	B-Application
(	O
Execute-In-Place	B-Application
)	O
,	O
etc	O
.	O
</s>
<s>
The	O
PCMCIA	B-Architecture
stack	O
for	B-Language
PalmDOS	O
was	O
partially	O
written	O
by	O
Ian	O
H	O
.	O
S	O
.	O
Cullimore	O
.	O
</s>
<s>
Novell	B-Operating_System
DOS	I-Operating_System
was	O
Novell	O
Corporation	O
's	O
name	O
for	B-Language
DRDOS	O
during	O
the	O
period	O
when	O
Novell	O
sold	O
DRDOS	O
,	O
after	O
the	O
acquisition	O
of	O
Digital	O
Research	O
in	O
1991	O
.	O
</s>
<s>
Regarding	O
features	O
and	O
performance	O
,	O
it	O
was	O
typically	O
at	O
least	O
one	O
release	O
ahead	O
of	O
MS-DOS	B-Application
.	O
</s>
<s>
In	O
1993	O
,	O
PC	O
DOS	B-Device
6.1	O
,	O
MS-DOS	B-Application
6.2	O
and	O
PC	O
DOS	B-Device
6.3	O
were	O
trumped	O
by	O
Novell	O
's	O
.	O
</s>
<s>
Novell	O
CEO	O
Robert	O
J	O
.	O
Frankenberg	O
's	O
strategy	O
included	O
"	O
major	O
trimming	O
"	O
,	O
selling	O
off	O
products	O
like	O
transactional	O
database	O
Btrieve	B-Application
and	O
killing	O
others	O
such	O
as	O
Novell	B-Operating_System
DOS	I-Operating_System
and	O
WordPerfect	B-Application
's	O
multimedia	O
Main	O
Street	O
children	O
's	O
titles	O
.	O
</s>
<s>
Novell	O
licensed	O
technology	O
from	O
Stac	O
Electronics	O
for	B-Language
use	O
in	O
Novell	B-Operating_System
DOS	I-Operating_System
and	O
its	O
Network	B-Protocol
operating	I-Protocol
system	I-Protocol
,	O
NetWare	B-Operating_System
.	O
</s>
<s>
Novell	O
sold	O
the	O
product	O
line	O
off	O
to	O
Caldera	O
on	O
23	O
July	O
1996	O
,	O
after	O
it	O
approached	O
Novell	O
looking	O
for	B-Language
a	O
DOS	B-Device
operating	O
system	O
to	O
bundle	O
with	O
its	O
OpenLinux	B-Operating_System
distribution	O
.	O
</s>
<s>
(	O
This	O
was	O
part	O
of	O
a	O
massive	O
and	O
ultimately	O
disastrous	O
spending	O
spree	O
for	B-Language
Novell	O
:	O
they	O
bought	O
WordPerfect	B-Application
Corporation	I-Application
at	O
about	O
the	O
same	O
time	B-Device
,	O
some	O
of	O
Borland	O
's	O
products	O
,	O
and	O
invested	O
heavily	O
in	O
Unix	B-Application
as	O
well	O
.	O
)	O
</s>
<s>
The	O
planned	O
"	O
DRDOS	O
7.0	O
"	O
,	O
internally	O
named	O
"	O
Panther	O
"	O
,	O
intended	O
to	O
trump	O
Microsoft	O
's	O
troubled	O
MS-DOS	B-Application
6.0	O
,	O
was	O
repeatedly	O
delayed	O
,	O
while	O
Novell	O
was	O
working	O
on	O
an	O
optionally	O
loadable	O
Unix-like	O
multi-user	O
security	O
extension	O
(	O
with	O
,	O
if	O
loaded	O
,	O
file	O
commands	B-Application
like	O
BACKUP	B-Application
,	O
DELPURGE	O
,	O
MOVE	B-Device
,	O
TOUCH	B-Application
,	O
TREE	B-Device
,	O
UNDELETE	O
,	O
XATTRIB	O
,	O
XCOPY	O
,	O
XDEL	O
and	O
XDIR	B-Device
supporting	O
an	O
otherwise	O
disabled	O
/U:name	O
command	B-Application
line	I-Application
option	O
to	O
select	O
specific	O
users	O
or	O
groups	O
,	O
compatible	O
with	O
Multiuser	B-Operating_System
DOS	I-Operating_System
)	O
and	O
two	O
new	O
graphical	B-Application
user	I-Application
interfaces	I-Application
(	O
ViewMAX	B-Application
3	O
,	O
a	O
derivative	O
of	O
GEM	B-Application
,	O
and	O
"	O
Star	B-Operating_System
Trek	I-Operating_System
"	O
,	O
a	O
true	O
port	O
of	O
Apple	O
's	O
System	B-Operating_System
7.1	I-Operating_System
to	O
run	O
under	O
the	O
new	O
DRDOS	O
multitasker	O
named	O
"	O
Vladivar	O
"	O
)	O
.	O
</s>
<s>
When	O
DRDOS	O
eventually	O
arrived	O
in	O
December	O
1993	O
(	O
with	O
localized	O
versions	O
released	O
in	O
March	O
1994	O
)	O
,	O
renamed	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
(	O
a.k.a.	O
</s>
<s>
It	O
was	O
larger	O
and	O
lacked	O
some	O
finishing	O
touches	O
,	O
but	O
was	O
nevertheless	O
seen	O
as	O
best	O
DOS	B-Device
by	O
many	O
industry	O
experts	O
.	O
</s>
<s>
In	O
Germany	O
,	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
was	O
aggressively	O
marketed	O
with	O
the	O
slogan	O
""	O
(	O
Do	O
n't	O
trust	O
any	O
DOS	B-Device
below	O
7	O
)	O
in	O
the	O
press	O
and	O
with	O
free	O
demo	O
floppies	O
in	O
computer	O
magazines	O
.	O
</s>
<s>
The	O
campaign	O
aimed	O
at	O
20%	O
of	O
the	O
DOS	B-Device
market	O
and	O
resulted	O
in	O
about	O
1.5	O
million	O
copies	O
sold	O
until	O
February	O
1994	O
and	O
more	B-Device
than	O
3000	O
dealers	O
interested	O
to	O
carry	O
the	O
product	O
.	O
</s>
<s>
Novell	B-Operating_System
DOS	I-Operating_System
7	O
was	O
available	O
through	O
various	O
OEMs	O
,	O
a	O
dedicated	O
mail	O
order	O
shop	O
and	O
authorized	O
dealers	O
.	O
</s>
<s>
A	O
major	O
functional	O
addition	O
was	O
Novell	O
's	O
second	O
attempt	O
at	O
a	O
peer-to-peer	O
networking	O
system	O
,	O
Personal	B-Application
NetWare	I-Application
(	O
PNW	O
)	O
.	O
</s>
<s>
This	O
was	O
better	O
than	O
its	O
predecessor	O
,	O
NetWare	B-Application
Lite	I-Application
(	O
NWL	O
)	O
,	O
but	O
it	O
was	O
incompatible	O
with	O
Microsoft	O
's	O
networking	O
system	O
,	O
now	O
growing	O
popular	O
with	O
support	O
in	O
Windows	B-Application
for	B-Language
Workgroups	O
,	O
OS/2	B-Application
,	O
and	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
A	O
considerable	O
amount	O
of	O
manual	O
configuration	O
was	O
needed	O
to	O
get	O
both	O
to	O
co-exist	O
on	O
the	O
same	O
PC	O
,	O
and	O
Personal	B-Application
NetWare	I-Application
never	O
achieved	O
much	O
success	O
.	O
</s>
<s>
Since	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
implemented	O
the	O
DOSMGR	O
API	B-Application
and	O
internal	O
data	O
structures	O
had	O
been	O
updated	O
,	O
its	O
BDOS	B-Operating_System
7.2	O
kernel	O
could	O
report	O
with	O
a	O
DOS	B-Device
version	O
of	O
6.0	O
and	O
OEM	O
ID	O
"	O
IBM	O
"	O
without	O
risking	O
compatibility	O
problems	O
with	O
Windows	B-Application
.	O
</s>
<s>
Most	O
tools	O
would	O
report	O
this	O
as	O
"	O
PCDOS	B-Operating_System
6.1	O
"	O
,	O
because	O
IBM	O
PCDOS	B-Operating_System
6.1	O
also	O
reported	O
as	O
DOS	B-Device
6.0	O
to	O
applications	O
.	O
</s>
<s>
Novell	B-Operating_System
DOS	I-Operating_System
7	O
introduced	O
much	O
advanced	O
memory	O
management	O
including	O
new	O
support	O
for	B-Language
DPMI	O
(	O
DOS	B-Device
Protected	O
Mode	O
Interface	O
)	O
and	O
DPMS	O
(	O
DOS	B-Device
Protected	O
Mode	O
Services	O
)	O
as	O
well	O
as	O
more	B-Device
flexible	O
loadhigh	O
options	O
.	O
</s>
<s>
It	O
also	O
introduced	O
support	O
for	B-Language
"	O
true	O
"	O
pre-emptive	O
multitasking	O
of	O
multiple	O
DOS	B-Device
applications	O
in	O
virtual	O
DOS	B-Device
machines	O
(	O
VDM	O
)	O
,	O
a	O
component	O
originally	O
named	O
MultiMAX	O
.	O
</s>
<s>
This	O
was	O
similar	O
to	O
Multiuser	B-Operating_System
DOS	I-Operating_System
,	O
but	O
now	O
on	O
the	O
basis	O
of	O
a	O
natively	O
DOS	B-Device
compatible	O
environment	O
,	O
similar	O
to	O
Windows	B-Application
386	B-General_Concept
Enhanced	O
Mode	O
,	O
but	O
without	O
a	O
GUI	B-Application
.	O
</s>
<s>
However	O
,	O
if	O
EMM386	B-Device
was	O
loaded	O
with	O
the	O
option	O
/MULTI	O
,	O
EMM386	B-Device
would	O
load	O
a	O
natively	O
32-bit	O
386	B-General_Concept
Protected	O
Mode	O
operating	O
system	O
core	O
providing	O
API	B-Application
support	O
for	B-Language
pre-emptive	O
multitasking	O
,	O
multi-threading	O
,	O
hardware	O
virtualization	O
and	O
domain	O
management	O
of	O
virtual	O
DOS	B-Device
machines	O
.	O
</s>
<s>
This	O
API	B-Application
could	O
be	O
used	O
by	O
DRDOS-aware	O
applications	O
.	O
</s>
<s>
If	O
TASKMGR	O
was	O
run	O
later	O
on	O
,	O
it	O
would	O
use	O
this	O
API	B-Application
to	O
instance	O
the	O
current	O
16-bit	O
DOS	B-Device
system	O
environment	O
,	O
create	O
virtual	O
DOS	B-Device
machines	O
and	O
run	O
applications	O
in	O
them	O
instead	O
of	O
using	O
its	O
own	O
Real	B-Application
Mode	I-Application
task-switcher	O
support	O
.	O
</s>
<s>
The	O
multitasker	O
was	O
compatible	O
with	O
Windows	B-Application
,	O
so	O
that	O
tasks	O
started	O
before	O
launching	O
Windows	B-Application
could	O
be	O
seen	O
as	O
tasks	O
under	O
Windows	B-Application
as	O
well	O
.	O
</s>
<s>
Novell	B-Operating_System
DOS	I-Operating_System
7	O
and	O
Personal	B-Application
NetWare	I-Application
1.0	O
also	O
shipped	O
with	O
NetWars	B-Application
,	O
a	O
network-enabled	O
3D	O
arcade	O
game	O
.	O
</s>
<s>
Novell	B-Operating_System
DOS	I-Operating_System
7	O
and	O
Personal	B-Application
NetWare	I-Application
required	O
several	O
bug-fix	O
releases	O
(	O
D70xyy	O
with	O
x	O
=	O
language	O
,	O
yy	O
=	O
number	O
)	O
and	O
were	O
not	O
completely	O
stable	O
when	O
the	O
next	O
development	O
occurred	O
.	O
</s>
<s>
With	O
beta	O
versions	O
of	O
Microsoft	O
's	O
"	O
Chicago	O
"	O
(	O
what	O
would	O
later	O
become	O
Windows	B-Application
95	I-Application
)	O
in	O
sight	O
,	O
Novell	O
wound	O
down	O
further	O
development	O
on	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
in	O
September	O
1994	O
and	O
stopped	O
maintenance	O
in	O
January	O
1996	O
after	O
more	B-Device
than	O
15	O
updates	O
.	O
</s>
<s>
When	O
Caldera	O
approached	O
Novell	O
looking	O
for	B-Language
a	O
DOS	B-Device
operating	O
system	O
to	O
bundle	O
with	O
their	O
OpenLinux	B-Operating_System
distribution	O
,	O
Novell	O
sold	O
the	O
product	O
line	O
off	O
to	O
Caldera	O
on	O
23	O
July	O
1996	O
,	O
by	O
which	O
time	B-Device
it	O
was	O
of	O
little	O
commercial	O
value	O
to	O
them	O
.	O
</s>
<s>
Between	O
the	O
Caldera-owned	O
DR-DOS	O
and	O
competition	O
from	O
IBM	O
's	O
PCDOS	B-Operating_System
6.3	O
,	O
Microsoft	O
moved	O
to	O
make	O
it	O
impossible	O
to	O
use	O
or	O
buy	O
the	O
subsequent	O
Windows	B-Application
version	O
,	O
Windows	B-Application
95	I-Application
,	O
with	O
any	O
DOS	B-Device
product	O
other	O
than	O
their	O
own	O
.	O
</s>
<s>
Immediately	O
after	O
the	O
completion	O
of	O
the	O
pre-trial	O
deposition	O
stage	O
(	O
where	O
the	O
parties	O
list	O
the	O
evidence	O
they	O
intend	O
to	O
present	O
)	O
,	O
there	O
was	O
an	O
out-of-court	O
settlement	O
on	O
7	O
January	O
2000	O
for	B-Language
an	O
undisclosed	O
sum	O
.	O
</s>
<s>
Gross	O
,	O
one	O
of	O
the	O
original	O
DR-DOS	O
engineers	O
,	O
with	O
a	O
proposal	O
to	O
restart	O
DR-DOS	O
development	O
and	O
to	O
make	O
Windows	B-Application
95	I-Application
run	O
on	O
DR-DOS	O
which	O
would	O
help	O
the	O
court	O
case	O
.	O
</s>
<s>
Besides	O
other	O
improvements	O
and	O
enhancements	O
all	O
over	O
the	O
system	O
,	O
a	O
string	O
of	O
new	O
key	O
features	O
were	O
added	O
subsequently	O
over	O
the	O
course	O
of	O
the	O
next	O
two	O
years	O
,	O
including	O
a	O
TCP/IP	B-Protocol
stack	I-Protocol
(	O
derived	O
from	O
LAN	O
WorkPlace	O
for	B-Language
DOS	B-Device
/	O
NetWare	B-Operating_System
Mobile	O
)	O
,	O
a	O
graphical	O
32-bit	O
DOS	B-Device
Protected	O
Mode	O
HTML	O
3.2	O
web-browser	O
DR-WebSpyder	B-Application
(	O
originally	O
based	O
on	O
source	O
code	O
from	O
the	O
Arachne	B-Language
web	I-Language
browser	I-Language
by	O
Michal	B-Language
Polák	I-Language
)	O
with	O
LAN	O
and	O
modem	O
dialup	O
,	O
a	O
POSIX	O
Pthreads	B-Operating_System
extension	O
to	O
the	O
multi-tasker	O
by	O
Andy	O
T	O
.	O
Wightman	O
,	O
long	O
filename	O
(	O
LONGNAME	O
)	O
support	O
by	O
Edward	O
N	O
.	O
Hill	O
,	O
Jr.	O
,	O
as	O
well	O
as	O
LBA	B-Device
and	O
FAT32	B-Application
support	O
(	O
DRFAT32	O
)	O
by	O
Matthias	O
R	O
.	O
Paul	O
.	O
</s>
<s>
Gross	O
also	O
hired	O
Andrew	O
Schulman	O
(	O
who	O
had	O
been	O
,	O
with	O
Geoff	O
Chappell	O
,	O
instrumental	O
in	O
identifying	O
the	O
AARD	O
code	O
in	O
1992	O
)	O
to	O
work	O
as	O
a	O
consultant	O
and	O
,	O
in	O
Andover	O
,	O
assist	O
Paul	O
in	O
his	O
work	O
on	O
"	O
WinGlue	O
"	O
,	O
a	O
secret	O
project	O
to	O
create	O
a	O
version	O
of	O
DR-DOS	O
compatible	O
with	O
Windows	B-Application
95	I-Application
,	O
98	B-Device
and	O
98	B-Device
SE	O
and	O
replace	B-Device
its	O
MS-DOS	O
7.xx	O
component	O
.	O
</s>
<s>
This	O
was	O
demonstrated	O
at	O
CeBIT	O
in	O
March	O
1998	O
,	O
and	O
later	O
,	O
in	O
a	O
small	O
team	O
,	O
developed	O
into	O
"	O
WinBolt	O
"	O
,	O
both	O
versions	O
of	O
DR-DOS	O
,	O
which	O
remained	O
unreleased	O
,	O
but	O
played	O
an	O
important	O
role	O
in	O
the	O
court	O
case	O
.	O
</s>
<s>
Caldera	O
UK	O
officially	O
released	O
Caldera	O
OpenDOS	O
7.01	O
on	O
3	O
February	O
1997	O
,	O
but	O
this	O
version	O
was	O
just	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
update	O
10	O
(	O
as	O
of	O
December	O
1994	O
)	O
compiled	O
only	O
with	O
the	O
necessary	O
adaptations	O
to	O
incorporate	O
the	O
new	O
name	O
in	O
display	O
messages	O
as	O
well	O
as	O
in	O
environment	O
variables	O
and	O
file	O
names	O
.	O
</s>
<s>
It	O
was	O
missing	O
a	O
year	O
's	O
worth	O
of	O
patches	O
which	O
had	O
been	O
developed	O
for	B-Language
the	O
Novell	B-Operating_System
DOS	I-Operating_System
updates	O
11	O
(	O
January	O
1995	O
)	O
to	O
15.2	O
(	O
January	O
1996	O
)	O
.	O
</s>
<s>
This	O
was	O
due	O
to	O
parts	O
of	O
the	O
Novell	B-Operating_System
DOS	I-Operating_System
sources	O
having	O
been	O
lost	O
at	O
Novell	O
meanwhile	O
.	O
</s>
<s>
Consequently	O
,	O
this	O
version	O
still	O
reported	O
an	O
internal	O
BDOS	B-Operating_System
version	O
of	O
7.2	O
,	O
identical	O
to	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
.	O
</s>
<s>
The	O
new	O
suite	O
also	O
lacked	O
the	O
SETFIFO	O
command	B-Operating_System
,	O
which	O
had	O
been	O
added	O
with	O
one	O
of	O
the	O
Novell	B-Operating_System
DOS	I-Operating_System
updates	O
,	O
as	O
well	O
as	O
Fifth	O
Generation	O
's	O
Search&Destroy	O
virus	O
scanner	O
and	O
FastBack	O
Plus	O
2.0	O
utility	O
,	O
which	O
previously	O
came	O
bundled	O
with	O
Novell	B-Operating_System
DOS	I-Operating_System
.	O
</s>
<s>
Instead	O
it	O
came	O
bundled	O
with	O
a	O
newer	O
version	O
of	O
PNUNPACK	B-Application
and	O
brought	O
a	O
much	O
advanced	O
version	O
of	O
NetWars	B-Application
.	O
</s>
<s>
Parts	O
of	O
OpenDOS	O
7.01	O
were	O
released	O
as	O
open	B-Application
source	I-Application
in	O
form	O
of	O
the	O
M.R.S.	O
</s>
<s>
kit	O
(	O
for	B-Language
Machine	O
Readable	O
Sources	O
)	O
in	O
May	O
1997	O
,	O
but	O
with	O
license	B-License
terms	O
mostly	O
incompatible	O
with	O
existing	O
open-source	B-Application
licenses	O
.	O
</s>
<s>
The	O
source	O
was	O
then	O
closed	B-Application
again	O
as	O
Gross	O
felt	O
this	O
would	O
undermine	O
the	O
commercial	O
aspirations	O
of	O
the	O
system	O
.	O
</s>
<s>
After	O
beta	O
releases	O
in	O
September	O
and	O
November	O
1997	O
,	O
the	O
next	O
official	O
release	O
came	O
in	O
December	O
1997	O
,	O
with	O
the	O
name	O
changed	O
to	O
Caldera	O
DR-OpenDOS	O
7.02	O
,	O
soon	O
followed	O
by	O
a	O
further	O
release	O
in	O
March	O
1998	O
,	O
when	O
the	O
DR-DOS	O
name	O
returned	O
as	O
Caldera	O
DR-DOS	O
7.02	O
,	O
now	O
for	B-Language
the	O
first	O
time	B-Device
written	O
with	O
a	O
hyphen	O
.	O
</s>
<s>
Version	O
7.02	O
(	O
now	O
reporting	O
itself	O
as	O
BDOS	B-Operating_System
7.3	O
)	O
incorporated	O
improved	O
BIOS	O
and	O
BDOS	B-Operating_System
issues	O
,	O
developed	O
by	O
Paul	O
,	O
adding	O
many	O
new	O
boot	B-Operating_System
and	O
configuration	O
options	O
,	O
integrating	O
many	O
compatibility	O
enhancements	O
,	O
bug-fixes	O
and	O
optimizations	O
for	B-Language
size	O
and	O
speed	O
,	O
and	O
re-implementing	O
all	O
fixes	O
of	O
the	O
missing	O
Novell	B-Operating_System
DOS	I-Operating_System
updates	O
.	O
</s>
<s>
The	O
BIOS	O
improved	O
the	O
coexistence	O
of	O
DR-DOS	O
with	O
Windows	B-Application
9x	O
and	O
its	O
support	O
for	B-Language
third-party	O
disk	O
compression	O
drivers	O
such	O
as	O
Microsoft	O
's	O
DriveSpace	B-General_Concept
.	O
</s>
<s>
It	O
introduced	O
a	O
diagnostics	O
mode	O
(	O
activated	O
by	O
Scroll	B-Device
Lock	I-Device
)	O
,	O
integrated	O
debugger	O
support	O
(	O
with	O
DEBUG	B-Device
=	I-Device
ON	I-Device
and	O
a	O
debugger	O
loaded	O
before	O
or	O
from	O
within	O
CONFIG.SYS	B-Device
)	O
and	O
more	B-Device
flexible	O
CONFIG.SYS	B-Device
tracing	O
capabilities	O
via	O
the	O
///	O
hotkeys	O
and	O
the	O
TRACE	B-Device
and	O
TIMEOUT	B-Device
commands	B-Application
,	O
thereby	O
also	O
improving	O
the	O
integration	O
of	O
alternative	O
command	B-Application
line	I-Application
shells	O
such	O
as	O
4DOS	B-Application
.	O
</s>
<s>
Together	O
with	O
LOADER	O
,	O
SYS	B-Language
/DR:ext	O
and	O
the	O
CHAIN	B-Device
directive	O
,	O
it	O
brought	O
enhanced	O
multi-configuration	O
support	O
for	B-Language
DR/D/CONFIG.ext	B-Device
files	O
and	O
came	O
with	O
enhancements	O
to	O
the	O
BASIC-like	O
CONFIG.SYS	B-Device
language	O
for	B-Language
more	B-Device
powerful	O
boot	B-Operating_System
menus	I-Operating_System
,	O
convenient	O
user	O
interaction	O
and	O
programmatical	O
acting	O
upon	O
conditions	O
(	O
CPU386	B-Device
)	O
,	O
return	O
codes	O
and	O
error	B-Device
levels	O
(	O
ERROR	B-Device
,	O
ONERROR	B-Device
)	O
.	O
</s>
<s>
It	O
also	O
allowed	O
to	O
change	O
the	O
SCROLLOCK	B-Device
,	O
CAPSLOCK	B-Device
,	O
INSERT	B-Device
and	O
VERIFY	B-Device
settings	O
as	O
well	O
as	O
the	O
SWITCHAR	B-Device
,	O
YESCHAR	B-Device
,	O
NOCHAR	B-Device
and	O
RESUMECHAR	B-Device
characters	O
.	O
</s>
<s>
Various	O
behavioural	O
details	O
could	O
be	O
controlled	O
with	O
new	O
parameters	O
/Q	O
(	O
Quiet	O
)	O
,	O
/L	O
(	O
Lowercase	O
)	O
,	O
/Y	O
(	O
Yes	O
)	O
and	O
/S	O
(	O
Switch	O
)	O
for	B-Language
SWITCHES	B-Device
.	O
</s>
<s>
Further	O
,	O
it	O
provided	O
optional	O
support	O
for	B-Language
a	O
LPT4	O
:	O
device	O
and	O
allowed	O
to	O
configure	O
the	O
built-in	O
COMx	B-Device
:	I-Device
and	O
LPTx	B-Device
:	I-Device
devices	O
as	O
well	O
as	O
to	O
change	O
the	O
PRN	B-Device
:	I-Device
and	O
AUX	B-Device
:	I-Device
defaults	O
.	O
</s>
<s>
The	O
handling	O
of	O
environment	O
variables	O
in	O
CONFIG.SYS	B-Device
was	O
improved	O
and	O
new	O
load-high	O
facilities	O
included	O
such	O
as	O
the	O
HIFILES/FILESHIGH	O
and	O
HIFCBS/FCBSHIGH	O
options	O
to	O
relocate	B-Library
file	O
handles	O
and	O
FCB	O
structures	O
into	O
UMBs	O
,	O
which	O
typically	O
gave	O
between	O
1	O
and	O
4KB	O
(	O
and	O
up	O
to	O
15KB	O
)	O
more	B-Device
free	O
conventional	B-Device
memory	I-Device
compared	O
to	O
previous	O
versions	O
,	O
or	O
the	O
HISHELL/SHELLHIGH	O
SIZE	O
directive	O
to	O
control	O
the	O
pre-allocation	O
of	O
HMA	B-Device
memory	O
for	B-Language
COMMAND.COM	B-Operating_System
,	O
which	O
helped	O
to	O
avoid	O
memory	O
fragmentation	O
and	O
thereby	O
typically	O
gave	O
between	O
5	O
and	O
8KB	O
more	B-Device
continuous	O
HMA	B-Device
memory	O
for	B-Language
HMA-capable	O
third-party	O
drivers	O
to	O
work	O
with	O
in	O
conjunction	O
with	O
third-party	O
command	B-Application
line	I-Application
shells	O
,	O
which	O
could	O
not	O
load	O
into	O
the	O
HMA	B-Device
as	O
COMMAND.COM	B-Operating_System
with	O
its	O
/MH	O
option	O
.	O
</s>
<s>
At	O
a	O
reduced	O
memory	O
footprint	O
version	O
7.02	O
also	O
brought	O
an	O
enhanced	O
NLS	B-General_Concept
4.xx	O
sub-system	O
by	O
Paul	O
to	O
allow	O
multiple	O
,	O
distributed	O
and	O
possibly	O
user-configured	O
COUNTRY.SYS	O
files	O
to	O
be	O
used	O
by	O
the	O
system	O
at	O
the	O
same	O
time	B-Device
in	O
a	O
hierarchical	O
model	O
.	O
</s>
<s>
This	O
also	O
gave	O
dynamic	O
parser	O
support	O
for	B-Language
MS-DOS/PCDOS	O
COUNTRY.SYS	O
file	O
formats	O
in	O
addition	O
to	O
DR-DOS	O
'	O
own	O
COUNTRY.SYS	O
formats	O
,	O
and	O
it	O
introduced	O
support	O
for	B-Language
the	O
ISO	O
8601	O
international	O
date	O
format	B-Application
(	O
including	O
automatic	O
detection	O
)	O
and	O
the	O
then-new	O
Euro	O
currency	O
.	O
</s>
<s>
Some	O
DR-DOS	O
files	O
such	O
as	O
IBMBIO.COM	O
,	O
IBMDOS.COM	O
and	O
COUNTRY.SYS	O
carried	O
misleading	O
file	O
extensions	O
for	B-Language
compatibility	O
reasons	O
;	O
with	O
DR-DOS	O
7.02	O
they	O
were	O
enhanced	O
to	O
incorporate	O
a	O
fat	B-Application
binary-style	O
safety	O
feature	O
devised	O
by	O
Paul	O
so	O
that	O
they	O
would	O
exit	B-Device
gracefully	O
when	O
called	O
inappropriately	O
.	O
</s>
<s>
DR-DOS	O
7.02	O
was	O
fully	O
Year	B-Error_Name
2000	I-Error_Name
compliant	O
and	O
provided	O
special	O
support	O
to	O
work	O
with	O
buggy	O
system	O
BIOSes	O
.	O
</s>
<s>
It	O
also	O
came	O
with	O
an	O
updated	O
FDISK	B-Application
,	O
which	O
could	O
partition	O
and	O
format	B-Application
FAT32	B-Application
volumes	O
(	O
but	O
not	O
yet	O
work	O
with	O
LBA	B-Device
)	O
.	O
</s>
<s>
The	O
sources	O
of	O
the	O
Novell	O
patches	O
for	B-Language
the	O
external	O
tools	O
and	O
drivers	O
had	O
meanwhile	O
been	O
found	O
in	O
Germany	O
and	O
could	O
thus	O
be	O
retro-fitted	O
into	O
the	O
system	O
as	O
well	O
,	O
so	O
that	O
DR-DOS	O
7.02	O
finally	O
not	O
only	O
caught	O
up	O
with	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
,	O
but	O
was	O
a	O
true	O
step	O
forward	O
.	O
</s>
<s>
The	O
updated	O
internal	O
BDOS	B-Operating_System
version	O
number	O
introduced	O
a	O
new	O
problem	O
:	O
some	O
legacy	O
third-party	O
applications	O
with	O
special	O
support	O
for	B-Language
Novell	B-Operating_System
DOS	I-Operating_System
,	O
which	O
were	O
no	O
longer	O
being	O
updated	O
,	O
stopped	O
working	O
.	O
</s>
<s>
SETVER	B-Operating_System
already	O
allowed	O
Novell	B-Operating_System
DOS	I-Operating_System
to	O
disguise	O
itself	O
as	O
DOS	B-Device
versions	O
by	O
file	O
name	O
and	O
globally	O
and	O
,	O
specifying	O
a	O
magic	O
sub-version	O
of	O
255	O
,	O
it	O
would	O
even	O
disable	O
its	O
own	O
internal	O
BDOS	B-Operating_System
version	O
check	O
in	O
order	O
to	O
cope	O
with	O
programs	O
specifically	O
probing	O
for	B-Language
"	O
DR-DOS	O
"	O
.	O
</s>
<s>
The	O
modified	O
kernel	O
and	O
SETVER	B-Operating_System
driver	O
by	O
Paul	O
would	O
,	O
in	O
an	O
hierarchical	O
model	O
,	O
also	O
support	O
load	O
paths	O
in	O
order	O
to	O
distinguish	O
between	O
multiple	O
executables	O
of	O
the	O
same	O
file	O
name	O
,	O
and	O
it	O
introduced	O
an	O
extended	O
mode	O
,	O
in	O
which	O
SETVER	B-Operating_System
could	O
not	O
only	O
fake	O
DOS	B-Device
versions	O
,	O
but	O
also	O
BDOS	B-Operating_System
kernel	O
versions	O
.	O
</s>
<s>
Sub-versions	O
of	O
128	O
to	O
255	O
would	O
be	O
reported	O
as	O
DOS	B-Device
sub-versions	O
0	O
to	O
127	O
to	O
applications	O
,	O
but	O
with	O
the	O
BDOS	B-Operating_System
version	O
check	O
disabled	O
,	O
while	O
sub-versions	O
100	O
to	O
127	O
could	O
be	O
used	O
to	O
fake	O
different	O
BDOS	B-Operating_System
versions	O
,	O
whereas	O
the	O
DOS	B-Device
revision	O
number	O
(	O
typically	O
set	O
to	O
0	O
in	O
a	O
static	O
,	O
pre-boot	O
patchable	O
data	O
structure	O
)	O
would	O
be	O
taken	O
as	O
the	O
reported	O
sub-version	O
instead	O
,	O
so	O
that	O
SETVER	B-Operating_System
/G	O
/X	O
6.114	O
would	O
allow	O
versions	O
of	O
DR-DOS	O
since	O
7.02	O
to	O
still	O
report	O
themselves	O
as	O
a	O
"	O
DOS	B-Device
6.0	O
"	O
and	O
with	O
a	O
faked	O
BDOS	B-Operating_System
version	O
7.2	O
(	O
114	O
decimal	O
=	O
72	O
hexadecimal	O
)	O
,	O
thereby	O
masquerading	O
as	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
/	O
OpenDOS	O
7.01	O
.	O
</s>
<s>
While	O
otherwise	O
beneficial	O
,	O
the	O
new	O
HIFILES	B-Device
triggered	O
a	O
compatibility	O
problem	O
in	O
the	O
DOS-UP	O
feature	O
of	O
the	O
third-party	O
memory	O
manager	O
QEMM	B-Device
8	O
,	O
which	O
was	O
hard-wired	O
to	O
expect	O
a	O
chunk	B-General_Concept
of	O
five	O
handle	O
structures	O
in	O
conventional	B-Device
memory	I-Device
under	O
DR-DOS	O
(	O
as	O
with	O
previous	O
versions	O
up	O
to	O
7.01	O
)	O
,	O
whereas	O
version	O
7.02	O
by	O
design	O
left	O
eight	O
handles	O
in	O
low	B-Device
memory	I-Device
when	O
loading	O
high	O
files	O
in	O
order	O
to	O
maintain	O
full	O
compatibility	O
with	O
older	O
versions	O
of	O
Windows	B-Application
3.xx	O
.	O
</s>
<s>
Compatibility	O
with	O
Windows	B-Application
for	B-Language
Workgroups	O
3.11	O
had	O
not	O
been	O
affected	O
by	O
this	O
.	O
</s>
<s>
A	O
maintenance	O
fix	O
was	O
devised	O
to	O
patch	O
a	O
single	O
byte	O
in	O
IBMBIO.COM	O
in	O
order	O
to	O
switch	O
the	O
behaviour	O
and	O
optionally	O
re-invoke	O
the	O
old	O
chunking	B-General_Concept
.	O
</s>
<s>
This	O
freed	O
some	O
150	O
bytes	O
of	O
conventional	B-Device
memory	I-Device
and	O
enabled	O
full	O
compatibility	O
with	O
DOS-UP	O
,	O
but	O
at	O
the	O
same	O
time	B-Device
broke	O
compatibility	O
with	O
older	O
versions	O
of	O
Windows	B-Application
3.xx	O
when	O
using	O
the	O
HIFILES	B-Device
feature	O
,	O
and	O
vice	O
versa	O
.	O
</s>
<s>
The	O
patch	O
named	O
IBMBIO85.SCR	O
continued	O
to	O
work	O
with	O
newer	O
versions	O
of	O
DR-DOS	O
.	O
</s>
<s>
In	O
August	O
1998	O
the	O
US-based	O
Caldera	O
,	O
Inc	O
.	O
created	O
two	O
new	O
subsidiaries	O
,	O
Caldera	O
Systems	O
,	O
Inc	O
.	O
for	B-Language
the	O
Linux	B-Application
business	O
,	O
and	O
Caldera	O
Thin	O
Clients	O
,	O
Inc	O
.	O
for	B-Language
the	O
embedded	O
and	O
thin-client	O
market	O
.	O
</s>
<s>
Another	O
version	O
,	O
DR-DOS	O
7.03	O
(	O
still	O
with	O
BDOS	B-Operating_System
7.3	O
and	O
reporting	O
itself	O
to	O
applications	O
as	O
"	O
PCDOS	B-Operating_System
6.0	O
"	O
for	B-Language
compatibility	O
purposes	O
)	O
,	O
was	O
pre-released	O
at	O
Christmas	O
1998	O
and	O
then	O
officially	O
released	O
on	O
6	O
January	O
1999	O
by	O
Caldera	O
UK	O
.	O
</s>
<s>
It	O
came	O
with	O
significantly	O
improved	O
memory	O
managers	O
(	O
in	O
particular	O
enhanced	O
DPMI	O
support	O
in	O
conjunction	O
with	O
the	O
multitasker	O
)	O
and	O
other	O
enhancements	O
,	O
such	O
as	O
added	O
DEVLOAD	O
and	O
DRMOUSE	O
utilities	O
,	O
but	O
a	O
changed	O
OEM	O
label	B-Device
in	O
the	O
boot	B-Device
sector	I-Device
of	O
volumes	O
formatted	O
under	O
DR-DOS	O
could	O
also	O
cause	O
problems	O
under	O
other	O
operating	O
systems	O
(	O
which	O
can	O
be	O
circumvented	O
by	O
NOVOLTRK	O
)	O
.	O
</s>
<s>
DR-DOS	O
7.03	O
would	O
become	O
the	O
last	O
version	O
of	O
DR-DOS	O
also	O
tailored	O
for	B-Language
desktop	O
use	O
.	O
</s>
<s>
Caldera	O
,	O
Inc	O
.	O
wanted	O
to	O
relocate	B-Library
the	O
DR-DOS	O
business	O
into	O
the	O
US	O
and	O
closed	B-Application
the	O
highly	O
successful	O
UK	O
operation	O
in	O
February	O
1999	O
after	O
Gross	O
resigned	O
and	O
set	O
up	O
iCentrix	B-Protocol
to	O
develop	O
the	O
MarioNet	B-Protocol
split	I-Protocol
web	I-Protocol
browser	I-Protocol
.	O
</s>
<s>
Development	O
was	O
then	O
moved	O
into	O
the	O
US	O
(	O
which	O
never	O
worked	O
out	O
due	O
to	O
a	O
total	O
lack	O
of	O
expertise	O
in	O
this	O
field	O
at	O
Caldera	O
US	O
)	O
,	O
and	O
the	O
DR-DOS	O
line	O
fell	O
to	O
its	O
branch	O
company	O
,	O
Caldera	O
Thin	O
Clients	O
,	O
which	O
was	O
renamed	O
Lineo	O
,	O
Inc	O
.	O
on	O
20	O
July	O
1999	O
.	O
</s>
<s>
DR-WebSpyder	B-Application
was	O
renamed	O
Embrowser	B-Protocol
and	O
was	O
said	O
to	O
be	O
ported	O
to	O
Linux	B-Application
.	O
</s>
<s>
Lineo	O
re-released	O
DR-DOS	O
7.03	O
in	O
June	O
and	O
September	O
1999	O
,	O
still	O
branded	O
as	O
"	O
Caldera	O
DR-DOS	O
"	O
and	O
without	O
any	O
changes	O
,	O
but	O
otherwise	O
focussed	O
on	O
Linux	B-Application
for	I-Application
embedded	I-Application
systems	I-Application
,	O
based	O
on	O
a	O
stripped-down	O
version	O
of	O
OpenLinux	B-Operating_System
named	O
Embedix	O
.	O
</s>
<s>
Among	O
the	O
latest	O
and	O
independently	O
developed	O
versions	O
of	O
DR-DOS	O
were	O
OEM	O
DR-DOS	O
7.04	O
(	O
as	O
of	O
19	O
August	O
1999	O
)	O
and	O
7.05	O
(	O
as	O
of	O
30	O
November	O
1999	O
)	O
,	O
still	O
branded	O
as	O
"	O
Caldera	O
DR-DOS	O
"	O
.	O
</s>
<s>
These	O
were	O
variants	O
of	O
the	O
system	O
consisting	O
only	O
of	O
the	O
kernel	O
and	O
command	B-Operating_System
shell	O
.	O
</s>
<s>
With	O
a	O
specialized	O
native	O
implementation	O
of	O
FAT32	B-Application
and	O
large	O
hard	O
disk	O
support	O
they	O
could	O
be	O
found	O
bundled	O
with	O
Ontrack	O
's	O
Easy	O
Recovery	O
5	O
in	O
2000	O
,	O
replacing	O
the	O
dynamically-loadable	O
DRFAT32	O
redirector	O
driver	O
,	O
which	O
still	O
came	O
with	O
Easy	O
Recovery	O
4	O
.	O
</s>
<s>
They	O
were	O
also	O
used	O
for	B-Language
Seagate	O
Technology	O
's	O
SeaTools	B-Application
and	O
the	O
CD	B-Application
imaging	O
software	O
Nero	B-Application
Burning	I-Application
ROM	I-Application
.	O
</s>
<s>
While	O
still	O
reporting	O
a	O
BDOS	B-Operating_System
7.3	O
internally	O
,	O
these	O
were	O
the	O
first	O
versions	O
to	O
report	O
themselves	O
as	O
"	O
PCDOS	B-Operating_System
7.10	O
"	O
to	O
applications	O
in	O
order	O
to	O
indicate	O
integrated	O
FAT32	B-Application
support	O
.	O
</s>
<s>
Designed	O
to	O
be	O
mostly	O
backwards-compatible	O
,	O
the	O
DR-DOS	O
7.04/7.05	O
IBMBIO.COM	O
could	O
be	O
combined	O
with	O
the	O
DR-DOS	O
7.03	O
IBMDOS.COM	O
in	O
order	O
to	O
give	O
the	O
desktop-approved	O
DR-DOS	O
7.03	O
kernel	O
LBA	B-Device
capabilities	O
and	O
work	O
with	O
drives	O
larger	O
than	O
8	O
GB	O
.	O
</s>
<s>
For	B-Language
specific	O
OEM	O
requirements	O
,	O
DR-DOS	O
7.06	O
(	O
as	O
of	O
14	O
December	O
1999	O
)	O
by	O
Wightman	O
combined	O
the	O
kernel	O
files	O
into	O
a	O
single	O
binary	O
executable	O
,	O
so	O
that	O
,	O
similar	O
to	O
IO.SYS	O
of	O
Windows	B-Device
98	I-Device
,	O
it	O
could	O
be	O
booted	O
by	O
MS-DOS	O
7.10	O
boot	B-Device
sectors	I-Device
(	O
but	O
no	O
longer	O
by	O
DR-DOS	O
boot	B-Device
sectors	I-Device
)	O
.	O
</s>
<s>
DR-DOS	O
7.07	O
(	O
with	O
BDOS	B-Operating_System
7.4/7.7	O
)	O
by	O
Paul	O
introduced	O
new	O
bootstrap	B-Operating_System
loaders	I-Operating_System
and	O
updated	O
disk	O
tools	O
in	O
order	O
to	O
combine	O
support	O
for	B-Language
CHS	B-Device
and	O
LBA	B-Device
disk	O
access	O
,	O
the	O
FAT12	B-Application
,	O
FAT16	B-Application
and	O
FAT32	B-Application
file	O
systems	O
,	O
and	O
the	O
differing	O
bootstrapping	O
conventions	O
of	O
DR-DOS	O
,	O
PCDOS	B-Operating_System
,	O
MS-DOS	B-Application
,	O
Windows	B-Application
,	O
REAL/32	B-Operating_System
and	O
LOADER	O
into	O
a	O
single	O
NEWLDR	O
MBR	B-Device
and	O
boot	B-Device
sector	I-Device
,	O
so	O
that	O
the	O
code	O
would	O
continue	O
to	O
load	O
any	O
version	O
of	O
DR-DOS	O
down	O
to	O
3.31	O
(	O
and	O
since	O
DR-DOS	O
7.04	O
also	O
with	O
FAT32	B-Application
support	O
)	O
,	O
but	O
could	O
also	O
be	O
used	O
to	O
launch	O
the	O
PCDOS	B-Operating_System
or	O
MS-DOS	B-Application
system	O
files	O
,	O
including	O
those	O
of	O
Windows	B-Application
9x	O
and	O
PCDOS	B-Operating_System
7.10	O
.	O
</s>
<s>
At	O
the	O
same	O
time	B-Device
the	O
kernel	O
could	O
not	O
only	O
be	O
booted	O
by	O
the	O
new	O
sectors	O
,	O
but	O
also	O
by	O
any	O
previously	O
DR-DOS	O
formatted	O
disks	O
,	O
as	O
well	O
as	O
off	O
disks	O
with	O
existing	O
PCDOS	B-Operating_System
or	O
MS-DOS	B-Application
boot	B-Device
sectors	I-Device
and	O
a	O
variety	O
of	O
other	O
boot-loaders	O
,	O
thereby	O
easing	O
the	O
coexistence	O
and	O
setup	O
of	O
multi-boot	B-Operating_System
scenarios	O
in	O
conjunction	O
with	O
other	O
operating	O
systems	O
.	O
</s>
<s>
They	O
have	O
continued	O
to	O
sell	O
DR-DOS	O
for	B-Language
use	O
in	O
embedded	O
systems	O
.	O
</s>
<s>
DR-DOS	O
8.0	O
was	O
released	O
on	O
30	O
March	O
2004	O
featuring	O
FAT32	B-Application
and	O
large	O
disk	O
support	O
,	O
the	O
ability	O
to	O
boot	B-Operating_System
from	O
ROM	O
or	O
Flash	O
,	O
multitasking	O
and	O
a	O
DPMI	O
memory	O
manager	O
.	O
</s>
<s>
The	O
company	O
later	O
released	O
DR-DOS	O
8.1	O
(	O
with	O
better	O
FAT32	B-Application
support	O
)	O
in	O
autumn	O
2005	O
.	O
</s>
<s>
DR-DOS	O
8.1	O
was	O
withdrawn	O
for	B-Language
GPL	B-License
violations	O
(	O
see	O
Controversies	O
)	O
.	O
</s>
<s>
The	O
OpenDOS	O
7.01	O
source	O
code	O
was	O
a	O
base	O
for	B-Language
The	O
DR-DOS/OpenDOS	O
Enhancement	O
Project	O
,	O
set	O
up	O
in	O
July	O
2002	O
in	O
an	O
attempt	O
to	O
bring	O
the	O
functionality	O
of	O
DR-DOS	O
up	O
to	O
parity	O
with	O
modern	O
PC	O
non-Windows	O
operating	O
systems	O
.	O
</s>
<s>
The	O
project	O
's	O
added	O
native	O
support	O
for	B-Language
large	O
disks	O
(	O
LBA	B-Device
)	O
and	O
the	O
FAT32	B-Application
file	O
system	O
,	O
and	O
several	O
other	O
enhancements	O
,	O
including	O
improved	O
memory	O
management	O
and	O
support	O
for	B-Language
the	O
new	O
FAT32+	B-Application
file	O
system	O
extension	O
which	O
allows	O
files	O
of	O
up	O
to	O
256	O
GB	O
in	O
size	O
on	O
normal	O
FAT	B-Application
partitions	I-Application
.	O
</s>
<s>
DR-DOS	O
7.01.08	O
was	O
released	O
on	O
21	O
July	O
2011	O
.	O
</s>
<s>
In	O
October	O
2005	O
,	O
it	O
was	O
discovered	O
that	O
DR-DOS	O
8.1	O
included	O
several	O
utilities	O
from	O
FreeDOS	B-Application
as	O
well	O
as	O
other	O
sources	O
,	O
and	O
that	O
the	O
kernel	O
was	O
an	O
outdated	O
version	O
of	O
the	O
Enhanced	O
DR-DOS	O
kernel	O
.	O
</s>
<s>
DRDOS	O
,	O
Inc	O
.	O
failed	O
to	O
comply	O
with	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
by	O
not	O
crediting	O
the	O
FreeDOS	B-Application
utilities	O
to	O
their	O
authors	O
and	O
including	O
the	O
source	O
code	O
.	O
</s>
<s>
After	O
complaints	O
from	O
FreeDOS	B-Application
developers	O
(	O
including	O
the	O
suggestion	O
to	O
provide	O
the	O
source	O
code	O
,	O
and	O
hence	O
comply	O
with	O
the	O
GPL	B-License
)	O
,	O
DRDOS	O
,	O
Inc	O
.	O
instead	O
withdrew	O
version	O
8.1	O
,	O
and	O
also	O
the	O
unaffected	O
8.0	O
,	O
from	O
its	O
website	O
.	O
</s>
<s>
APPEND	O
,	O
ASSIGN	O
,	O
BATCH	O
,	O
DBG	O
,	O
DELQ	B-Device
,	O
ERA	B-Device
,	O
ERAQ	B-Device
,	O
MORE	B-Device
and	O
SUBST	O
have	O
been	O
among	O
the	O
internal	O
commands	B-Application
supported	O
since	O
DRDOS	O
3.31	O
.	O
</s>
<s>
GOSUB	O
,	O
IDLE	O
,	O
RETURN	O
and	O
SWITCH	O
were	O
added	O
as	O
internal	O
commands	B-Application
with	O
DRDOS	O
6.0	O
.	O
</s>
<s>
ASSIGN	O
and	O
SUBST	O
were	O
changed	O
to	O
become	O
external	O
commands	B-Application
with	O
DRDOS	O
6.0	O
.	O
</s>
<s>
ECHOERR	O
and	O
PAUSEERR	O
existed	O
as	O
internal	O
commands	B-Application
in	O
DRDOS	O
6.0	O
(	O
and	O
in	O
Multiuser	B-Operating_System
DOS	I-Operating_System
)	O
,	O
but	O
were	O
not	O
normally	O
enabled	O
.	O
</s>
<s>
MORE	B-Device
remained	O
an	O
internal	O
command	B-Operating_System
up	O
to	O
including	O
PalmDOS	O
,	O
but	O
was	O
changed	O
to	O
an	O
external	O
command	B-Operating_System
with	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
.	O
</s>
<s>
DBG	O
was	O
removed	O
with	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
,	O
LOADHIGH	O
,	O
LH	O
and	O
TRUENAME	O
were	O
added	O
as	O
internal	O
commands	B-Application
.	O
</s>
<s>
APPEND	O
was	O
still	O
an	O
internal	O
command	B-Operating_System
in	O
DRDOS	O
6.0	O
,	O
but	O
was	O
changed	O
to	O
an	O
external	O
command	B-Operating_System
with	O
Novell	B-Operating_System
DOS	I-Operating_System
7	O
.	O
</s>
<s>
The	O
following	O
list	O
of	O
internal	O
commands	B-Application
is	O
supported	O
by	O
DR	O
DOS	B-Device
6.0	O
:	O
</s>
<s>
Batch	O
processing	O
subcommands	O
of	O
DR	O
DOS	B-Device
6.0	O
include	O
:	O
</s>
<s>
DR	O
DOS	B-Device
6.0	O
supports	O
the	O
following	O
external	O
commands	B-Application
:	O
</s>
