<s>
The	O
UNISERVO	B-Device
tape	O
drive	O
was	O
the	O
primary	O
I/O	B-General_Concept
device	I-General_Concept
on	O
the	B-Operating_System
UNIVAC	I-Operating_System
I	O
computer	O
.	O
</s>
<s>
The	O
UNISERVO	B-Device
used	O
metal	O
tape	O
:	O
a	O
thin	O
strip	O
of	O
nickel-plated	O
phosphor	O
bronze	O
(	O
called	O
Vicalloy	O
)	O
1200	O
feet	O
long	O
.	O
</s>
<s>
The	O
UNISERVO	B-Device
supported	O
both	O
forward	O
and	O
backward	O
modes	O
on	O
read	O
or	O
write	O
operation	O
.	O
</s>
<s>
This	O
offered	O
significant	O
advantages	O
in	O
data	O
sorting	B-Algorithm
and	O
merging	B-Algorithm
applications	O
.	O
</s>
<s>
The	O
data	O
transfers	O
to/from	O
the	B-Operating_System
UNIVAC	I-Operating_System
I	O
processor	O
were	O
fully	O
buffered	O
in	O
a	O
one	O
block	O
dedicated	O
memory	O
,	O
permitting	O
instruction	O
execution	O
in	O
parallel	O
with	O
tape	O
movement	O
and	O
data	O
transfer	O
.	O
</s>
<s>
UNIVAC	O
continued	O
to	O
use	O
the	O
name	O
UNISERVO	B-Device
for	O
later	O
models	O
of	O
tape	O
drive	O
(	O
e.g.	O
,	O
UNISERVO	B-Device
II	O
,	O
UNISERVO	B-Device
IIIC	O
,	O
UNISERVO	B-Device
VIII-C	O
)	O
for	O
later	O
computers	O
in	O
their	O
product	O
line	O
.	O
</s>
<s>
The	O
UNISERVO	B-Device
II	O
could	O
read	O
metal	O
tapes	O
from	O
the	B-Operating_System
UNIVAC	I-Operating_System
I	O
as	O
well	O
as	O
use	O
higher	O
density	O
PET	O
film	O
base/ferric	O
oxide	O
media	O
tapes	O
that	O
became	O
the	O
industry	O
standard	O
.	O
</s>
<s>
The	O
tape	O
motion	O
in	O
the	O
UNISERVO	B-Device
I	I-Device
was	O
controlled	O
by	O
a	O
single	O
capstan	O
connected	O
to	O
a	O
synchronous	O
motor	O
.	O
</s>
<s>
Supply	O
and	O
take-up	O
reel	O
motion	O
was	O
buffered	O
via	O
a	O
complex	O
pulley-string-spring	O
arrangement	O
,	O
as	O
the	O
design	O
was	O
prior	O
to	O
the	O
invention	O
of	O
the	O
vacuum	B-Device
column	I-Device
buffer	O
.	O
</s>
<s>
The	O
UNISERVO	B-Device
I	I-Device
had	O
a	O
high-speed	O
rewind	O
capability	O
,	O
and	O
multiple	O
drives	O
on	O
the	B-Operating_System
UNIVAC	I-Operating_System
I	O
could	O
rewind	O
while	O
others	O
continued	O
with	O
data	O
processing	O
reads	O
or	O
writes	O
.	O
</s>
<s>
The	O
later	O
UNISERVO	B-Device
IIA	O
and	O
IIIA	O
omitted	O
the	O
plastic	O
wear	O
tape	O
and	O
felt	O
wipers	O
,	O
since	O
they	O
were	O
primarily	O
used	O
with	O
PET	O
film-base	O
magnetic	O
tape	O
.	O
</s>
<s>
Both	O
continued	O
the	O
use	O
of	O
single	O
capstan	O
drives	O
and	O
were	O
vacuum	B-Device
column	I-Device
designs	O
.	O
</s>
<s>
The	O
IIIC	O
and	O
later	O
tapes	O
used	O
NRZI	O
encoding	O
to	O
be	O
compatible	O
with	O
the	O
IBM	B-Device
729	I-Device
series	O
tape	O
drives	O
which	O
set	O
the	O
industry	O
standard	O
for	O
data	O
interchange	O
.	O
</s>
