<s>
Introduced	O
in	O
the	O
early	O
1990s	O
,	O
the	O
Micro	B-Device
Solutions	I-Device
Backpack	I-Device
was	O
a	O
device	O
allowing	O
users	O
to	O
attach	O
a	O
peripheral	O
drive	O
,	O
namely	O
hard	B-Device
drives	I-Device
,	O
CD-ROM	B-Device
drives	I-Device
,	O
and	O
DVD±RW	O
drives	O
,	O
to	O
their	O
system	O
.	O
</s>
<s>
When	O
the	O
original	O
model	O
was	O
released	O
,	O
USB	B-Protocol
ports	O
did	O
not	O
yet	O
exist	O
,	O
so	O
the	O
drive	O
plugged	O
into	O
a	O
system	O
's	O
printer	B-Device
port	I-Device
.	O
</s>
<s>
Backpacks	O
could	O
be	O
daisy-chained	B-Application
and	O
still	O
allow	O
for	O
printer	O
usage	O
.	O
</s>
<s>
Later	O
models	O
introduced	O
faster	O
connectivity	O
to	O
the	O
host	O
system	O
by	O
means	O
of	O
a	O
proprietary	O
PC	O
Card	O
,	O
and	O
later	O
USB	B-Protocol
.	O
</s>
