<s>
The	O
IBM	B-Device
Portable	I-Device
Personal	I-Device
Computer	I-Device
5155	O
model	O
68	O
is	O
an	O
early	O
portable	B-Device
computer	I-Device
developed	O
by	O
IBM	O
after	O
the	O
success	O
of	O
the	O
suitcase-size	O
Compaq	B-Device
Portable	I-Device
.	O
</s>
<s>
It	O
was	O
released	O
in	O
February	O
1984	O
and	O
was	O
quickly	O
replaced	O
by	O
the	O
IBM	B-Device
Convertible	I-Device
,	O
only	O
roughly	O
two	O
years	O
after	O
its	O
debut	O
.	O
</s>
<s>
The	O
Portable	O
was	O
basically	O
a	O
PC/XT	B-Device
motherboard	O
,	O
transplanted	O
into	O
a	O
Compaq-style	O
luggable	B-Device
case	O
.	O
</s>
<s>
The	O
system	O
featured	O
256	O
kilobytes	O
of	O
memory	O
(	O
expandable	O
to	O
640KB	O
)	O
,	O
an	O
added	O
CGA	B-Device
card	O
connected	O
to	O
an	O
internal	O
monochrome	O
amber	O
composite	O
monitor	O
,	O
and	O
one	O
or	O
two	O
half-height	O
-inch	O
360KB	O
floppy	B-Device
disk	I-Device
drives	I-Device
,	O
manufactured	O
by	O
Qume	O
.	O
</s>
<s>
Unlike	O
the	O
Compaq	B-Device
Portable	I-Device
,	O
which	O
used	O
a	O
dual-mode	O
monitor	O
and	O
special	O
display	O
card	O
,	O
IBM	O
used	O
a	O
stock	O
CGA	B-Device
card	O
and	O
a	O
9-inch	O
amber	O
monochrome	O
composite	O
monitor	O
,	O
which	O
had	O
lower	O
resolution	O
.	O
</s>
<s>
Experts	O
stated	O
that	O
IBM	O
developed	O
the	O
Portable	O
in	O
part	O
because	O
its	O
sales	O
force	O
needed	O
a	O
computer	O
that	O
would	O
compete	O
against	O
the	O
Compaq	B-Device
Portable	I-Device
.	O
</s>
<s>
Typically	O
in	O
a	O
two-drive	O
context	O
,	O
floppy	B-Device
drive	I-Device
A	O
:	O
ran	O
the	O
operating	O
system	O
,	O
and	O
drive	O
B	O
:	O
would	O
be	O
used	O
for	O
application	O
and	O
data	O
diskettes	B-Device
.	O
</s>
<s>
At	O
thirty	O
pounds	O
,	O
it	O
may	O
have	O
been	O
difficult	O
to	O
carry	O
for	O
some	O
,	O
and	O
was	O
often	O
referred	O
to	O
as	O
“	O
luggable	B-Device
”	O
.	O
</s>
