<s>
The	B-Application
Fourth	I-Application
Protocol	I-Application
is	O
an	O
interactive	O
fiction	O
video	O
game	O
based	O
on	O
Frederick	O
Forsyth	O
's	O
1984	O
spy	O
novel	O
The	B-Application
Fourth	I-Application
Protocol	I-Application
.	O
</s>
<s>
The	O
game	O
was	O
released	O
for	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
in	O
July	O
1985	O
,	O
with	O
the	O
Commodore	O
64	O
release	O
following	O
one	O
month	O
later	O
,	O
and	O
the	O
Amstrad	B-Device
CPC	I-Device
conversion	O
in	O
1986	B-Application
.	O
</s>
<s>
The	O
IBM	B-Device
PC	I-Device
version	O
was	O
developed	O
for	O
the	O
Electronic	O
Pencil	O
company	O
,	O
by	O
a	O
developer	O
named	O
Brian	O
Mallett	O
.	O
</s>
<s>
Macintosh-like	O
icons	B-Device
are	O
used	O
to	O
assign	O
watchers	O
and	O
navigate	O
until	O
text-based	O
interaction	O
becomes	O
available	O
in	O
the	O
third	O
section	O
.	O
</s>
<s>
The	O
Cencom	O
icon	B-Device
offers	O
access	O
to	O
Preston	O
's	O
personal	O
files	O
where	O
the	O
player	O
can	O
store	O
information	O
throughout	O
the	O
first	O
part	O
of	O
the	O
game	O
.	O
</s>
<s>
The	O
Assessment	O
icon	B-Device
gives	O
the	O
player	O
an	O
idea	O
of	O
their	O
progress	O
,	O
telling	O
the	O
player	O
how	O
much	O
of	O
the	O
first	O
stage	O
they	O
have	O
solved	O
and	O
their	O
current	O
rating	O
at	O
MI5	O
.	O
</s>
<s>
Using	O
surveillance	O
the	O
player	O
can	O
assign	O
'	O
watchers	O
 '	O
to	O
targets	O
;	O
these	O
are	O
informants	O
who	O
provide	O
valuable	O
information	O
,	O
in	O
addition	O
to	O
memos	O
and	O
reports	O
,	O
which	O
will	O
be	O
brought	O
to	O
the	O
player	O
's	O
attention	O
via	O
the	O
sitreps	O
icon	B-Device
.	O
</s>
<s>
The	O
calendar	O
icon	B-Device
lets	O
the	O
player	O
know	O
how	O
much	O
time	O
has	O
passed	O
.	O
</s>
<s>
The	O
telephone	O
icon	B-Device
allows	O
the	O
player	O
to	O
accept	O
calls	O
or	O
call	O
out	O
.	O
</s>
<s>
This	O
section	O
adds	O
additional	O
icons	B-Device
to	O
control	O
movement	O
,	O
along	O
with	O
a	O
manipulate	O
icon	B-Device
to	O
take	O
,	O
drop	O
and	O
use	O
objects	O
.	O
</s>
<s>
The	O
communicate	O
icon	B-Device
allows	O
the	O
player	O
to	O
talk	O
to	O
others	O
,	O
via	O
the	O
phone	O
if	O
needed	O
.	O
</s>
