<s>
Styx	B-Application
was	O
is	O
a	O
video	O
game	O
released	O
by	O
Windmill	O
Software	O
in	O
1983	O
as	O
a	O
copy-protected	B-Application
,	O
bootable	O
5.25	O
"	O
floppy	O
disk	O
for	O
the	O
IBM	B-Device
PC/XT	I-Device
.	O
</s>
<s>
It	O
is	O
a	O
clone	O
of	O
the	O
1981	B-Application
arcade	O
game	O
Qix	B-Device
.	O
</s>
<s>
There	O
are	O
three	O
significant	O
differences	O
from	O
Qix	B-Device
:	O
the	O
caterpillar	O
(	O
that	O
can	O
grow	O
in	O
size	O
in	O
later	O
rounds	O
)	O
,	O
the	O
introduction	O
of	O
diagonal	O
movement	O
,	O
and	O
the	O
X1/X5/X10	O
multiplier	O
that	O
would	O
color	O
a	O
claimed	O
area	O
corresponding	O
to	O
the	O
color	O
of	O
the	O
multiplier	O
(	O
also	O
awarding	O
that	O
many	O
points	O
)	O
.	O
</s>
<s>
Styx	B-Application
uses	O
the	O
same	O
game	O
engine	O
as	O
two	O
other	O
Windmill	O
Software	O
games	O
,	O
The	O
Exterminator	O
and	O
Moonbugs	O
,	O
and	O
these	O
were	O
some	O
of	O
the	O
few	O
programs	O
to	O
make	O
use	O
of	O
the	O
16-color	O
quasi-graphics	O
CGA	O
mode	O
(	O
normally	O
the	O
CGA	O
could	O
only	O
use	O
4	O
or	O
2	O
color	O
graphics	O
)	O
.	O
</s>
<s>
However	O
,	O
it	O
was	O
possible	O
to	O
play	O
on	O
a	O
monochrome	B-Device
monitor	I-Device
as	O
long	O
as	O
the	O
graphics	O
card	O
also	O
supported	O
color	O
graphics	O
(	O
e.g.	O
</s>
<s>
Styx	B-Application
,	O
The	O
Exterminator	O
,	O
and	O
Moonbugs	O
set	O
CGA	O
320x200x4	O
mode	O
on	O
the	O
title	O
screen	O
by	O
directly	O
manipulating	O
the	O
video	O
registers	O
;	O
this	O
causes	O
them	O
to	O
display	O
a	O
screen	O
full	O
of	O
garbage	O
on	O
later	O
video	O
cards	O
.	O
</s>
<s>
In	O
September	O
2004	O
the	O
source	O
code	O
of	O
the	O
game	O
became	O
available	O
"	O
for	O
historical	O
interest	O
"	O
(	O
with	O
other	O
Windmill	O
Software	O
games	O
such	O
as	O
Digger	B-Application
)	O
.	O
</s>
<s>
Also	O
,	O
there	O
is	O
a	O
reverse	O
engineered	O
variant	O
from	O
Andrew	O
Jenner	O
,	O
called	O
Styx	B-Application
Remastered	O
.	O
</s>
