<s>
The	O
Macintosh	B-Device
Portable	I-Device
is	O
a	O
laptop	B-Device
designed	O
,	O
manufactured	O
,	O
and	O
sold	O
by	O
Apple	O
Computer	O
,	O
Inc	O
.	O
from	O
September	O
1989	O
to	O
October	O
1991	O
.	O
</s>
<s>
It	O
is	O
the	O
first	O
battery-powered	O
Macintosh	B-Device
,	O
which	O
garnered	O
significant	O
excitement	O
from	O
critics	O
,	O
but	O
sales	O
to	O
customers	O
were	O
quite	O
low	O
.	O
</s>
<s>
It	O
featured	O
a	O
fast	O
,	O
sharp	O
,	O
and	O
expensive	O
monochrome	O
active	B-Device
matrix	I-Device
LCD	I-Device
screen	O
in	O
a	O
hinged	O
design	O
that	O
covered	O
the	O
keyboard	O
when	O
the	O
machine	O
was	O
not	O
in	O
use	O
.	O
</s>
<s>
The	O
Portable	O
was	O
one	O
of	O
the	O
early	O
consumer	O
laptops	B-Device
to	O
employ	O
an	O
active	B-General_Concept
matrix	I-General_Concept
panel	O
—	O
only	O
the	O
most	O
expensive	O
of	O
the	O
initial	O
PowerBook	B-Device
line	O
,	O
the	O
PowerBook	B-Device
170	I-Device
,	O
had	O
such	O
a	O
panel	O
.	O
</s>
<s>
The	O
Portable	O
has	O
features	O
similar	O
to	O
the	O
Atari	B-Device
STacy	I-Device
,	O
a	O
version	O
of	O
their	O
Atari	B-Device
ST	I-Device
computer	O
which	O
contained	O
a	O
built	O
in	O
keyboard	O
and	O
monitor	O
.	O
</s>
<s>
Macintosh	B-Device
Portable	I-Device
can	O
run	O
Macintosh	O
System	O
6.0.4	O
through	O
System	B-Operating_System
7.5.5	I-Operating_System
.	O
</s>
<s>
The	O
pointer	O
was	O
a	O
built-in	O
trackball	B-Device
that	O
could	O
be	O
removed	O
and	O
located	O
on	O
either	O
side	O
of	O
the	O
keyboard	O
.	O
</s>
<s>
There	O
were	O
three	O
drive	O
configurations	O
available	O
for	O
Macintosh	B-Device
Portable	I-Device
.	O
</s>
<s>
A	O
Portable	O
could	O
ship	O
with	O
one	O
floppy	O
drive	O
,	O
with	O
two	O
floppy	O
drives	O
,	O
or	O
with	O
a	O
hard	B-Device
drive	I-Device
and	O
a	O
floppy	O
drive	O
.	O
</s>
<s>
Most	O
Macintosh	B-Device
Portable	I-Device
units	O
came	O
with	O
a	O
hard	B-Device
drive	I-Device
.	O
</s>
<s>
It	O
was	O
a	O
custom-engineered	O
Conner	O
CP-3045	O
(	O
known	O
by	O
Apple	O
as	O
"	O
Hard	B-Device
Disk	I-Device
40SC	O
"	O
)	O
.	O
</s>
<s>
It	O
holds	O
40	O
MB	O
of	O
data	O
,	O
consumes	O
less	O
power	O
compared	O
to	O
most	O
hard	B-Device
drives	I-Device
of	O
its	O
time	O
,	O
and	O
it	O
has	O
a	O
proprietary	O
SCSI	O
connector	O
;	O
adapters	O
that	O
allow	O
standard	O
SCSI	O
drives	O
to	O
be	O
used	O
on	O
the	O
Portable	O
exist	O
,	O
but	O
they	O
are	O
expensive	O
.	O
</s>
<s>
At	O
16	O
pounds	O
(	O
7.2	O
kilograms	O
)	O
and	O
4inches	O
(	O
10	O
centimetres	O
)	O
thick	O
,	O
the	O
Portable	O
was	O
a	O
heavy	O
and	O
bulky	O
portable	B-Device
computer	I-Device
.	O
</s>
<s>
The	O
main	O
contributor	O
to	O
the	O
Portable	O
's	O
weight	O
and	O
bulk	O
was	O
its	O
lead-acid	B-Device
battery	I-Device
.	O
</s>
<s>
Despite	O
the	O
dramatic	O
improvement	O
in	O
terms	O
of	O
ergonomics	O
offered	O
by	O
the	O
responsiveness	O
,	O
sharpness	O
,	O
and	O
uniformity	O
of	O
its	O
active	B-General_Concept
matrix	I-General_Concept
panel	O
,	O
one	O
of	O
the	O
primary	O
drawbacks	O
of	O
the	O
Portable	O
was	O
poor	O
readability	O
in	O
low-light	O
situations	O
.	O
</s>
<s>
Consequently	O
,	O
in	O
February	O
1991	O
,	O
Apple	O
introduced	O
a	O
backlit	O
Macintosh	B-Device
Portable	I-Device
(	O
model	O
M5126	O
)	O
.	O
</s>
<s>
The	O
backlight	O
feature	O
was	O
a	O
welcomed	O
improvement	O
,	O
but	O
it	O
reduced	O
the	O
battery	B-Architecture
life	O
by	O
about	O
a	O
half	O
.	O
</s>
<s>
An	O
upgrade	O
kit	O
was	O
also	O
offered	O
for	O
the	O
earlier	O
model	O
as	O
well	O
,	O
which	O
plugged	O
into	O
the	O
ROM	B-Device
expansion	O
slot	O
.	O
</s>
<s>
The	O
Portable	O
used	O
expensive	O
SRAM	B-Architecture
memory	O
in	O
an	O
effort	O
to	O
maximize	O
battery	B-Architecture
life	O
and	O
to	O
provide	O
an	O
"	O
instant	O
on	O
"	O
low-power	O
sleep	O
mode	O
.	O
</s>
<s>
In	O
the	O
newer	O
backlit	O
Portable	O
,	O
Apple	O
changed	O
SRAM	B-Architecture
memory	O
to	O
the	O
less	O
expensive	O
(	O
but	O
more	O
power-hungry	O
)	O
pseudo-SRAM	O
,	O
which	O
reduced	O
the	O
total	O
RAM	O
expansion	O
to	O
8MB	O
,	O
and	O
lowered	O
the	O
price	O
.	O
</s>
<s>
The	O
lead-acid	B-Device
battery	I-Device
on	O
the	O
non-backlit	O
Portable	O
offered	O
up	O
to	O
ten	O
hours	O
of	O
usage	O
time	O
,	O
and	O
the	O
Portable	O
draws	O
the	O
same	O
amount	O
of	O
power	O
when	O
turned	O
off	O
,	O
and	O
when	O
in	O
sleep	O
mode	O
.	O
</s>
<s>
Unlike	O
later	O
portable	B-Device
computers	I-Device
from	O
Apple	O
and	O
other	O
manufacturers	O
,	O
the	O
battery	B-Architecture
is	O
wired	O
in-series	O
with	O
the	O
AC	O
power	O
supply	O
.	O
</s>
<s>
There	O
being	O
no	O
possible	O
alternative	O
direct	O
connection	O
to	O
the	O
AC	O
supply	O
,	O
a	O
dead	O
battery	B-Architecture
meant	O
that	O
the	O
computer	O
could	O
not	O
be	O
operated	O
.	O
</s>
<s>
Several	O
popular	O
unauthorized	O
workarounds	O
were	O
devised	O
,	O
including	O
using	O
a	O
power	O
supply	O
from	O
the	O
PowerBook	B-Device
100	I-Device
series	O
,	O
which	O
provides	O
higher	O
output	O
.	O
</s>
<s>
As	O
with	O
automotive	O
batteries	O
,	O
the	O
sealed	O
lead-acid	B-Device
cells	I-Device
used	O
in	O
the	O
Portable	O
failed	O
if	O
they	O
were	O
fully	O
discharged	O
.	O
</s>
<s>
The	O
batteries	O
are	O
no	O
longer	O
manufactured	O
and	O
it	O
is	O
very	O
rare	O
to	O
find	O
an	O
original	O
battery	B-Architecture
that	O
will	O
hold	O
a	O
charge	O
and	O
allow	O
the	O
computer	O
to	O
start	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
repack	O
the	O
battery	B-Architecture
with	O
new	O
cells	O
,	O
or	O
use	O
alternative	O
6V	O
batteries	O
.	O
</s>
<s>
There	O
were	O
three	O
lead-acid	B-Device
cells	I-Device
inside	O
the	O
battery	B-Architecture
:	O
each	O
were	O
manufactured	O
by	O
Gates	O
Energy	O
Products	O
(	O
now	O
EnerSys	O
)	O
,	O
and	O
they	O
were	O
also	O
used	O
in	O
Quantum	O
1	O
battery	B-Architecture
packs	O
for	O
photographic	O
flash	O
use	O
.	O
</s>
<s>
There	O
is	O
some	O
indication	O
that	O
Apple	O
executives	O
at	O
the	O
time	O
,	O
particularly	O
,	O
Jean-Louis	O
Gassée	O
,	O
were	O
aware	O
of	O
the	O
design	O
problems	O
concerning	O
the	O
Macintosh	B-Device
Portable	I-Device
.	O
</s>
<s>
These	O
problems	O
,	O
combined	O
with	O
supply	O
issues	O
of	O
the	O
newly	O
developed	O
active	B-Device
matrix	I-Device
screen	I-Device
,	O
caused	O
numerous	O
delays	O
in	O
launching	O
the	O
computer	O
.	O
</s>
<s>
Initial	O
officially	O
announced	O
launch	O
dates	O
indicated	O
that	O
the	O
Macintosh	B-Device
Portable	I-Device
would	O
be	O
available	O
by	O
June	O
1988	O
.	O
</s>
<s>
The	O
Macintosh	B-Device
Portable	I-Device
itself	O
also	O
suggests	O
a	O
lengthy	O
development	O
time	O
with	O
a	O
silkscreen	O
date	O
stamp	O
of	O
1987	O
on	O
the	O
production	O
keyboard	O
PCB	O
,	O
indicating	O
a	O
close-to-final	O
design	O
was	O
likely	O
to	O
have	O
been	O
determined	O
by	O
then	O
.	O
</s>
<s>
The	O
Macintosh	B-Device
Portable	I-Device
product	O
launch	O
was	O
held	O
at	O
the	O
Universal	O
Amphitheater	O
in	O
Universal	O
City	O
,	O
California	O
at	O
an	O
estimated	O
cost	O
of	O
$1	O
million	O
with	O
over	O
5,000	O
guests	O
.	O
</s>
<s>
Others	O
noted	O
that	O
the	O
computer	O
seemed	O
behind	O
the	O
times	O
compared	O
to	O
competing	O
laptops	B-Device
,	O
stating	O
that	O
"	O
This	O
machine	O
would	O
have	O
been	O
OK	O
12	O
months	O
or	O
18	O
months	O
ago	O
.	O
</s>
<s>
Apple	O
then	O
reduced	O
the	O
price	O
of	O
the	O
Macintosh	B-Device
Portable	I-Device
by	O
$	O
1,000	O
in	O
1990	O
,	O
just	O
7	O
months	O
after	O
launch	O
,	O
and	O
discontinued	O
the	O
computer	O
in	O
1991	O
with	O
the	O
launch	O
of	O
its	O
replacement	O
,	O
the	O
PowerBook	B-Device
series	O
.	O
</s>
<s>
The	O
Outbound	B-Application
laptop	I-Application
was	O
a	O
Mac-compatible	O
laptop	B-Device
available	O
during	O
the	O
same	O
time	O
period	O
as	O
the	O
Portable	O
.	O
</s>
<s>
It	O
was	O
also	O
restricted	O
to	O
4	O
MB	O
of	O
RAM	O
,	O
due	O
to	O
the	O
requirement	O
that	O
users	O
install	O
a	O
ROM	B-Device
chip	I-Device
from	O
an	O
Apple	O
machine	O
such	O
as	O
Macintosh	B-Device
Plus	I-Device
.	O
</s>
