<s>
The	O
Compaq	B-Device
Portable	I-Device
386	I-Device
is	O
a	O
computer	O
released	O
by	O
Compaq	O
Computer	O
Corporation	O
in	O
1987	O
.	O
</s>
<s>
It	O
was	O
equipped	O
with	O
a	O
Intel	B-General_Concept
80386	I-General_Concept
CPU	B-General_Concept
,	O
RAM	B-Architecture
,	O
ROM	O
,	O
floppy	B-Device
,	O
hard	B-Device
disk	I-Device
drive	I-Device
,	O
priced	O
at	O
respectively	O
,	O
and	O
a	O
gas-plasma	O
display	O
.	O
</s>
<s>
Early	O
versions	O
of	O
the	O
Compaq	B-Device
Portable	I-Device
386	I-Device
were	O
sold	O
with	O
the	O
Compaq	B-Device
Portable	I-Device
III	I-Device
case	O
and	O
badges	O
.	O
</s>
<s>
A	O
differing	O
screen	O
bezel	O
stating	O
"	O
386/20	O
"	O
was	O
the	O
only	O
externally	O
visible	O
change	O
.	O
</s>
<s>
Network	B-Protocol
General	I-Protocol
resold	O
a	O
customized	O
version	O
of	O
the	O
Compaq	B-Device
Portable	I-Device
386	I-Device
as	O
the	O
"	O
Sniffer	B-Protocol
"	O
Network	O
Analyzer	O
.	O
</s>
<s>
The	O
Portable	O
386	B-General_Concept
got	O
its	O
name	O
due	O
to	O
the	O
socketed	O
Intel	O
386DX	B-General_Concept
CPU	B-General_Concept
with	O
20MHz	O
.	O
</s>
<s>
There	O
is	O
also	O
an	O
additional	O
socket	O
for	O
a	O
20MHz	O
387	O
FPU	B-General_Concept
option	O
,	O
which	O
was	O
not	O
included	O
in	O
the	O
basic	O
configuration	O
of	O
the	O
Portable	O
.	O
</s>
<s>
Since	O
the	O
whole	O
system	O
bus	O
runs	O
with	O
CPU	B-General_Concept
frequency	O
,	O
there	O
is	O
no	O
way	O
to	O
improve	O
the	O
CPU	B-General_Concept
performance	O
by	O
installing	O
a	O
386DX	B-General_Concept
CPU	B-General_Concept
with	O
more	O
than	O
20MHz	O
other	O
than	O
the	O
rare	O
Cyrix	O
486DRx2	O
20/40	O
which	O
has	O
a	O
multiplicator	O
of	O
2	O
for	O
the	O
frequency	O
while	O
being	O
still	O
pinout	O
compatible	O
with	O
the	O
386	B-General_Concept
socket	O
.	O
</s>
<s>
The	O
mainboard	O
can	O
take	O
up	O
to	O
four	O
proprietary	O
512KB	O
SIMMs	O
which	O
were	O
called	O
SC-RAM	O
in	O
the	O
Portable	O
manual	O
.	O
</s>
<s>
Installing	O
the	O
so-called	O
32bit	O
Memory-/Modem	O
board	O
expansion	O
offers	O
a	O
socket	O
for	O
another	O
expansion	O
card	O
which	O
has	O
4MB	O
(	O
8×512	O
KB	O
80	O
ns	O
)	O
of	O
memory	O
and	O
another	O
expansion	O
socket	O
installed	O
on	O
which	O
the	O
user	O
can	O
install	O
a	O
3rd	O
expansion	O
card	O
with	O
another	O
4MB	O
(	O
again	O
8×512	O
KB	O
80	O
ns	O
)	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
These	O
RAM	B-Architecture
expansion	O
cards	O
were	O
available	O
through	O
Compaq	O
or	O
third	O
party	O
manufacturers	O
,	O
such	O
as	O
Kingston	O
Technology	O
.	O
</s>
<s>
The	O
graphics	O
card	O
can	O
be	O
configured	O
between	O
CGA	B-Device
and	O
MDA	B-Device
emulation	O
mode	O
whereas	O
the	O
CGA	B-Device
mode	O
is	O
mandatory	O
for	O
using	O
Microsoft	O
Windows	O
 '	O
Compaq	O
Plasma	O
Driver	O
and	O
graphic	O
capabilities	O
in	O
general	O
.	O
</s>
<s>
The	O
internal	O
CGA	B-Device
graphics	I-Device
card	O
is	O
able	O
to	O
display	O
a	O
resolution	O
up	O
to	O
640x400	O
pixels	O
with	O
a	O
color	O
depth	O
of	O
2	O
bits	O
(	O
monochrome	O
)	O
,	O
which	O
has	O
been	O
first	O
seen	O
in	O
the	O
AT&T	B-Operating_System
6300	I-Operating_System
built	O
by	O
Olivetti	O
,	O
surpassing	O
the	O
original	O
IBM	O
standard	O
by	O
200	O
pixels	O
in	O
height	O
while	O
remaining	O
fully	O
CGA	B-Device
compatible	O
elsewhere	O
.	O
</s>
<s>
The	O
Portable	O
offers	O
two	O
drive	B-Device
bays	I-Device
for	O
5.25	B-Device
"	I-Device
half-height	B-Device
drives	O
where	O
one	O
is	O
reserved	O
for	O
the	O
hard	B-Device
disk	I-Device
and	O
the	O
other	O
one	O
for	O
the	O
internal	O
floppy	B-Device
disk	I-Device
drive	I-Device
.	O
</s>
<s>
Compaq	O
originally	O
offered	O
a	O
40MB	O
and	O
100MB	O
hard	B-Device
disk	I-Device
option	O
.	O
</s>
<s>
Quite	O
common	O
back	O
in	O
the	O
days	O
,	O
the	O
BIOS	O
of	O
the	O
Compaq	O
only	O
offers	O
to	O
select	O
preconfigured	O
hard	B-Device
disk	I-Device
configurations	O
like	O
Type	O
17	O
for	O
40MB	O
or	O
42	O
for	O
504MB	O
.	O
</s>
<s>
There	O
is	O
no	O
detailed	O
information	O
about	O
the	O
underlying	O
CHS	B-Device
configuration	O
of	O
these	O
types	O
available	O
.	O
</s>
<s>
The	O
device	O
suffers	O
from	O
the	O
wide-spread	O
CHS	B-Device
barrier	I-Device
,	O
not	O
allowing	O
hard	B-Device
disk	I-Device
drives	I-Device
greater	O
than	O
504MB	O
.	O
</s>
<s>
In	O
its	O
basic	O
configuration	O
,	O
Compaq	O
offered	O
only	O
a	O
single	O
5.25	B-Device
"	I-Device
1.2MB	O
floppy	B-Device
disk	I-Device
drive	I-Device
aside	O
of	O
the	O
40MB	O
hard	B-Device
disk	I-Device
drive	I-Device
,	O
but	O
there	O
was	O
also	O
a	O
cheaper	O
option	O
for	O
a	O
secondary	O
5.25	B-Device
"	I-Device
360KB	O
floppy	B-Device
disk	I-Device
drive	I-Device
instead	O
of	O
the	O
hard	B-Device
disk	I-Device
.	O
</s>
<s>
Giving	O
the	O
fact	O
that	O
the	O
Portable	O
uses	O
a	O
standard	O
floppy	B-Device
drive	I-Device
connector	O
and	O
has	O
built-in	O
support	O
in	O
the	O
BIOS	O
,	O
one	O
can	O
easily	O
replace	O
the	O
5.25	B-Device
"	I-Device
with	O
a	O
3.5	B-Device
"	I-Device
1.44MB	O
drive	O
.	O
</s>
<s>
As	O
mentioned	O
before	O
,	O
there	O
is	O
an	O
expansion	O
unit	O
available	O
which	O
extends	O
the	O
Portable	O
by	O
two	O
full-size	O
16bit	O
ISA	B-Architecture
slots	I-Architecture
.	O
</s>
<s>
Compaq	O
advertised	O
ISA	B-Architecture
cards	I-Architecture
like	O
the	O
COMPAQ-VG-Controller	O
card	O
to	O
be	O
used	O
with	O
the	O
expansion	O
unit	O
.	O
</s>
<s>
There	O
was	O
also	O
an	O
expansion	O
unit	O
for	O
a	O
40MB	O
tape	O
drive	O
offered	O
,	O
which	O
looks	O
identical	O
to	O
the	O
ISA	B-Architecture
expansion	O
unit	O
from	O
outside	O
,	O
except	O
for	O
offering	O
only	O
a	O
slot	O
for	O
the	O
tape	O
drive	O
.	O
</s>
<s>
Compaq	O
offered	O
multiple	O
expansion	O
cards	O
for	O
the	O
Portable	O
386	B-General_Concept
,	O
which	O
can	O
be	O
installed	O
inside	O
the	O
main	O
housing	O
.	O
</s>
<s>
The	O
1-2MB	O
memory	O
expansion	O
must	O
be	O
installed	O
on	O
the	O
32bit	O
carrier	O
board	O
and	O
comes	O
with	O
1MB	O
of	O
RAM	B-Architecture
preinstalled	O
and	O
offers	O
two	O
more	O
SC-RAM	O
slots	O
for	O
1MB	O
SC-RAM	O
memory	O
modules	O
each	O
.	O
</s>
<s>
The	O
BIOS	O
setup	O
utility	O
is	O
not	O
preinstalled	O
in	O
an	O
EPROM	O
chip	O
,	O
but	O
comes	O
on	O
a	O
single	O
floppy	B-Device
disk	I-Device
.	O
</s>
<s>
Compaq	O
bundled	O
Compaq-DOS	B-Application
in	O
version	O
3.31	O
with	O
the	O
Portable	O
386	B-General_Concept
,	O
a	O
variant	O
of	O
MS-DOS	B-Application
3.2	O
which	O
already	O
offered	O
support	O
for	O
FAT16	O
and	O
hard	B-Device
disk	I-Device
partitions	O
with	O
more	O
than	O
32MB	O
.	O
</s>
<s>
A	O
Windows	O
2.01	O
OEM	O
version	O
was	O
also	O
available	O
which	O
makes	O
use	O
of	O
the	O
386	B-General_Concept
memory	O
management	O
.	O
</s>
<s>
There	O
was	O
also	O
a	O
User	O
Programs	O
disk	O
bundled	O
with	O
the	O
Portable	O
which	O
offers	O
tools	O
for	O
memory	O
management	O
and	O
adapting	O
the	O
CPU	B-General_Concept
speed	O
(	O
between	O
6	O
,	O
8	O
and	O
20MHz	O
)	O
:	O
</s>
<s>
ADAPT.COM	O
(	O
Advanced	O
Display	O
Attribute	O
Programming	O
Tool	O
)	O
a	O
TSR	O
application	O
to	O
configure	O
the	O
CGA/MDA	O
charsets	O
on	O
the	O
fly	O
.	O
</s>
<s>
CEMM.EXE	O
(	O
386	B-General_Concept
CPU	B-General_Concept
)	O
/	O
CEMMP.EXE	O
(	O
286	O
CPU	B-General_Concept
)	O
,	O
Compaq	O
Expanded	O
Memory	O
Manager	O
,	O
a	O
memory	O
manager	O
which	O
is	O
incompatible	O
with	O
Windows	O
3.x	O
.	O
</s>
<s>
MODE.COM	O
replaced	O
the	O
default	O
MODE.COM	O
application	O
of	O
MS-DOS	B-Application
and	O
allows	O
additional	O
commands	O
like	O
"	O
MODE	O
SEL	O
MDA	B-Device
"	O
,	O
"	O
MODE	O
SEL	O
CGA	B-Device
"	O
,	O
"	O
MODE	O
SPEED	O
HIGH	O
"	O
,	O
"	O
MODE	O
SPEED	O
LOW	O
"	O
to	O
switch	O
on	O
the	O
fly	O
between	O
the	O
Portable	O
's	O
graphics	O
and	O
CPU	B-General_Concept
frequency	O
modes	O
.	O
</s>
<s>
VDISK.SYS	O
is	O
a	O
virtual	B-Application
disk	I-Application
driver	O
which	O
makes	O
use	O
of	O
the	O
RAM	B-Architecture
.	O
</s>
