<s>
The	O
Thorn	B-Device
EMI	I-Device
Liberator	I-Device
was	O
a	O
laptop	B-Device
word	B-General_Concept
processor	I-General_Concept
,	O
produced	O
in	O
the	O
United	O
Kingdom	O
by	O
Thorn	O
EMI	O
Datatech	O
,	O
then	O
in	O
Feltham	O
Middlesex	O
,	O
primarily	O
intended	O
for	O
use	O
by	O
UK	O
Government	O
civil	O
servants	O
.	O
</s>
<s>
Released	O
in	O
1985	O
,	O
it	O
is	O
considered	O
to	O
be	O
the	O
first	O
mass-produced	O
British	O
laptop	B-Device
.	O
</s>
<s>
Thorn	O
EMI	O
Datatech	O
simultaneously	O
held	O
the	O
contracts	O
for	O
the	O
repair	O
of	O
the	O
Sinclair	B-Operating_System
ZX80	I-Operating_System
and	O
ZX81	O
.	O
</s>
<s>
Duncan	O
Smeed	O
wrote	O
the	O
low	O
level	O
system	O
software	O
and	O
worked	O
closely	O
with	O
Digital	O
Research	O
on	O
the	O
operating	B-General_Concept
system	I-General_Concept
implementation	O
.	O
</s>
<s>
John	O
Linney	O
created	O
the	O
embedded	O
word	B-General_Concept
processor	I-General_Concept
and	O
terminal	O
emulation	O
applications	O
.	O
</s>
<s>
The	O
Liberator	O
was	O
based	O
on	O
a	O
Zilog	B-General_Concept
Z80A	I-General_Concept
microprocessor	B-Architecture
and	O
a	O
Gate	O
array	O
implementing	O
the	O
screen	O
controller	O
,	O
keyboard	O
interface	O
and	O
other	O
I/O	O
logic	O
.	O
</s>
<s>
The	O
LCD	B-Device
display	I-Device
had	O
a	O
resolution	O
of	O
480	O
x	O
128	O
pixels	O
,	O
or	O
80	O
columns	O
by	O
16	O
lines	O
of	O
text	O
.	O
</s>
<s>
Interfaces	O
comprised	O
two	O
S5/8	O
serial	B-Protocol
ports	I-Protocol
and	O
two	O
expansion	O
buses	O
,	O
one	O
specifically	O
for	O
extra	O
RAM	O
.	O
</s>
<s>
Two	O
battery	O
packs	O
were	O
available	O
,	O
a	O
NiCad	O
rechargeable	O
pack	O
giving	O
12	O
hours	O
operation	O
,	O
or	O
one	O
holding	O
four	O
AA	B-Algorithm
cells	I-Algorithm
giving	O
16	O
hours	O
.	O
</s>
<s>
The	O
Liberator	O
had	O
40	O
kB	O
of	O
internal	O
RAM	O
as	O
standard	O
,	O
plus	O
an	O
optional	O
24	O
kB	O
which	O
could	O
be	O
write-protected	O
by	O
means	O
of	O
an	O
external	O
switch	O
and	O
had	O
its	O
own	O
button	B-Algorithm
cell	I-Algorithm
battery	O
to	O
provide	O
non-volatile	B-General_Concept
storage	I-General_Concept
.	O
</s>
<s>
Another	O
24	O
kB	O
of	O
non-volatile	B-General_Concept
RAM	O
could	O
be	O
plugged	O
into	O
the	O
external	O
RAM	O
expansion	O
bus	O
.	O
</s>
<s>
The	O
Liberator	O
's	O
custom	O
wordprocessing	O
software	O
ran	O
under	O
the	O
CP/M	B-Application
operating	I-Application
system	I-Application
.	O
</s>
