<s>
D/CAS	B-General_Concept
(	O
Data/CASsette	O
)	O
,	O
also	O
known	O
as	O
a	O
streamer	B-General_Concept
cassette	I-General_Concept
,	O
is	O
a	O
now-obsolete	O
data	B-Protocol
backup	I-Protocol
technology	O
that	O
used	O
an	O
upgraded	O
version	O
of	O
the	O
common	O
audio	B-Device
cassette	I-Device
tape	I-Device
and	O
a	O
specialized	O
tape	O
drive	O
derived	O
from	O
an	O
audio	O
tape	O
transport	O
.	O
</s>
<s>
Holding	O
anywhere	O
from	O
200	O
to	O
600	O
megabytes	O
,	O
it	O
was	O
superseded	O
by	O
newer	O
data	B-Protocol
backup	I-Protocol
formats	O
such	O
as	O
Travan	B-Device
,	O
QIC	B-Device
,	O
DDS	B-Architecture
,	O
and	O
LTO	B-Operating_System
.	O
</s>
<s>
Streamer	B-General_Concept
cassettes	I-General_Concept
look	O
almost	O
like	O
a	O
standard	B-Device
audio	I-Device
cassette	I-Device
,	O
with	O
the	O
addition	O
of	O
a	O
notch	O
about	O
one	O
quarter	O
inch	O
wide	O
and	O
deep	O
,	O
situated	O
slightly	O
off-center	O
at	O
the	O
top	O
edge	O
of	O
the	O
cassette	O
.	O
</s>
<s>
Data	O
was	O
recorded	O
in	O
four	O
tracks	O
in	O
a	O
serpentine	O
manner	O
across	O
the	O
whole	O
width	O
of	O
the	O
tape	O
,	O
much	O
like	O
newer	O
formats	O
such	O
as	O
QIC	B-Device
or	O
Travan	B-Device
,	O
making	O
them	O
single-sided	O
.	O
</s>
<s>
Streamer	B-General_Concept
cassettes	I-General_Concept
can	O
be	O
used	O
in	O
an	O
audio	B-Device
cassette	I-Device
deck	O
,	O
but	O
the	O
formulation	O
of	O
tape	O
they	O
contain	O
is	O
optimized	O
only	O
for	O
full-saturation	O
square	O
wave	O
digital	O
data	O
,	O
resulting	O
in	O
audio	O
recordings	O
made	O
on	O
them	O
having	O
very	O
poor	O
audio	O
quality	O
and	O
a	O
large	O
amount	O
of	O
noise	O
and	O
distortion	O
.	O
</s>
