<s>
Disk	B-Operating_System
Copy	I-Operating_System
was	O
the	O
default	O
utility	O
for	O
handling	O
logical	B-Application
volume	I-Application
images	I-Application
in	O
System	B-Operating_System
7	I-Operating_System
through	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.2	I-Operating_System
(	O
usable	O
in	O
System	B-Operating_System
Software	I-Operating_System
6	I-Operating_System
as	O
well	O
)	O
.	O
</s>
<s>
In	O
later	O
versions	O
of	O
macOS	B-Application
it	O
has	O
been	O
replaced	O
by	O
DiskImageMounter	O
for	O
mounting	O
the	O
images	O
and	O
Disk	B-Application
Utility	I-Application
for	O
creating	O
them	O
.	O
</s>
<s>
"	O
Disk	B-Operating_System
Copy	I-Operating_System
4.2	O
"	O
(	O
DC42	O
)	O
is	O
the	O
common	O
name	O
used	O
to	O
refer	O
to	O
disk	B-Application
images	I-Application
of	O
floppy	B-Device
disks	I-Device
created	O
by	O
the	O
4.2	O
version	O
of	O
Disk	B-Operating_System
Copy	I-Operating_System
.	O
</s>
<s>
Disk	B-Operating_System
Copy	I-Operating_System
6.0	O
added	O
support	O
for	O
the	O
New	B-Operating_System
Disk	I-Operating_System
Image	I-Operating_System
Format	I-Operating_System
(	O
NDIF	B-Operating_System
)	O
.	O
</s>
<s>
Versions	O
of	O
Disk	B-Operating_System
Copy	I-Operating_System
in	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
added	O
support	O
for	O
the	O
newer	O
Universal	O
Disk	O
Format	O
(	O
UDIF	B-Operating_System
)	O
image	O
format	O
,	O
introduced	O
with	O
DMG	B-Operating_System
files	O
in	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
Although	O
the	O
last	O
official	O
public	O
release	O
of	O
Disk	B-Operating_System
Copy	I-Operating_System
for	O
Mac	B-Operating_System
OS	I-Operating_System
9	I-Operating_System
was	O
version	O
6.3.3	O
,	O
there	O
was	O
to	O
be	O
a	O
version	O
6.5	O
that	O
supported	O
OS	B-Operating_System
X	I-Operating_System
's	O
UDIF	B-Operating_System
image	O
format	O
.	O
</s>
<s>
But	O
because	O
Apple	O
had	O
stopped	O
support	O
for	O
OS	B-Operating_System
9	I-Operating_System
already	O
,	O
support	O
for	O
the	O
old	O
OS	O
was	O
eventually	O
removed	O
in	O
favor	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
As	O
such	O
the	O
OS	B-Operating_System
9	I-Operating_System
version	O
of	O
6.5	O
only	O
ever	O
made	O
it	O
to	O
beta	O
13	O
before	O
development	O
on	O
it	O
stopped	O
.	O
</s>
<s>
Although	O
version	O
6.4	O
and	O
6.5	O
will	O
read	O
DMG	B-Operating_System
images	O
when	O
the	O
system	O
is	O
booted	O
into	O
OS	B-Operating_System
9	I-Operating_System
,	O
they	O
can	O
only	O
do	O
so	O
if	O
the	O
image	O
is	O
not	O
compressed	O
.	O
</s>
<s>
Other	O
image	O
formats	O
supported	O
by	O
Disk	B-Operating_System
Copy	I-Operating_System
include	O
DiskSet	O
and	O
raw	B-General_Concept
disk	I-General_Concept
images	I-General_Concept
.	O
</s>
<s>
Disk	B-Operating_System
Copy	I-Operating_System
was	O
also	O
the	O
name	O
of	O
an	O
Apple	O
utility	O
distributed	O
with	O
some	O
of	O
the	O
earliest	O
versions	O
of	O
the	O
classic	B-Application
Mac	I-Application
OS	I-Application
.	O
</s>
<s>
In	O
order	O
to	O
copy	O
400K	O
floppy	B-Device
disks	I-Device
using	O
as	O
few	O
disk	O
swaps	O
as	O
possible	O
on	O
a	O
machine	O
with	O
only	O
128K	O
of	O
RAM	B-Architecture
,	O
the	O
original	O
Disk	B-Operating_System
Copy	I-Operating_System
used	O
the	O
screen	B-Algorithm
buffer	I-Algorithm
to	O
store	O
binary	O
data	O
from	O
the	O
disk	O
being	O
copied	O
;	O
as	O
a	O
result	O
,	O
the	O
screen	O
(	O
other	O
than	O
a	O
small	O
area	O
at	O
the	O
bottom	O
displaying	O
the	O
GUI	B-Application
)	O
filled	O
with	O
noise	O
while	O
copying	O
was	O
in	O
progress	O
.	O
</s>
