<s>
The	O
TurboDuo	B-General_Concept
is	O
a	O
fourth-generation	B-Application
video	B-Device
game	I-Device
console	I-Device
developed	O
by	O
NEC	O
Home	O
Electronics	O
and	O
Hudson	O
Soft	O
for	O
the	O
North	O
American	O
market	O
.	O
</s>
<s>
The	O
TurboDuo	B-General_Concept
was	O
test-marketed	O
in	O
Los	O
Angeles	O
in	O
October	O
1992	O
,	O
before	O
a	O
nationwide	O
rollout	O
in	O
May	O
1993	O
.	O
</s>
<s>
It	O
is	O
the	O
North	O
American	O
version	O
of	O
the	O
Japanese	O
PC	B-General_Concept
Engine	I-General_Concept
Duo	I-General_Concept
game	O
console	O
which	O
was	O
released	O
in	O
September	O
1991	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
the	O
TurboDuo	B-General_Concept
was	O
marketed	O
by	O
Turbo	O
Technologies	O
,	O
Inc	O
.	O
(	O
or	O
TTI	O
)	O
of	O
Los	O
Angeles	O
,	O
a	O
joint	O
venture	O
of	O
NEC	O
Home	O
Electronics	O
and	O
Hudson	O
Soft	O
.	O
</s>
<s>
The	O
TurboDuo	B-General_Concept
integrates	O
the	O
capabilities	O
of	O
the	O
TurboGrafx-16	B-General_Concept
and	O
its	O
CD-ROM	B-Device
drive	O
(	O
the	O
TurboGrafx-CD	O
)	O
into	O
a	O
single	O
,	O
redesigned	O
unit	O
with	O
an	O
updated	O
BIOS	B-Operating_System
and	O
192	O
KB	O
of	O
additional	O
RAM	B-Architecture
.	O
</s>
<s>
TTI	O
also	O
offered	O
the	O
Super	O
System	O
Card	O
via	O
mail	O
order	O
,	O
which	O
provided	O
the	O
original	O
TurboGrafx-CD	O
with	O
the	O
192	O
KB	O
RAM	B-Architecture
upgrade	O
.	O
</s>
<s>
The	O
RAM	B-Architecture
increase	O
and	O
BIOS	B-Operating_System
update	O
afford	O
the	O
TurboDuo	B-General_Concept
and	O
PC	B-General_Concept
Engine	I-General_Concept
Duo	I-General_Concept
compatibility	O
with	O
all	O
CD-ROM²	O
and	O
Super	O
CD-ROM²	O
titles	O
(	O
Japanese	O
and	O
North	O
American	O
)	O
.	O
</s>
<s>
Like	O
the	O
TurboGrafx-CD	O
,	O
the	O
TurboDuo	B-General_Concept
can	O
read	O
Compact	O
Disc	O
Digital	O
Audio	O
and	O
CD+G	O
discs	O
.	O
</s>
<s>
The	O
TurboDuo	B-General_Concept
,	O
however	O
,	O
cannot	O
read	O
PC	B-General_Concept
Engine	I-General_Concept
HuCards	B-Device
without	O
modification	O
or	O
an	O
adapter	O
.	O
</s>
<s>
With	O
a	O
HuCard	B-Device
adapter	O
and	O
an	O
Arcade	O
Card	O
Duo	O
,	O
the	O
TurboDuo	B-General_Concept
can	O
also	O
read	O
Arcade	O
CD-ROM²	O
games	O
(	O
which	O
were	O
sold	O
only	O
in	O
Japan	O
)	O
.	O
</s>
<s>
When	O
the	O
PC	B-General_Concept
Engine	I-General_Concept
Duo	I-General_Concept
launched	O
in	O
Japan	O
on	O
September	O
21	O
,	O
1991	O
,	O
it	O
retailed	O
for	O
¥	O
59,800	O
.	O
</s>
<s>
The	O
Duo	O
R	O
omits	O
the	O
3.5	B-Device
mm	I-Device
phone	I-Device
connector	I-Device
for	O
headphones	B-Device
,	O
and	O
the	O
locking	O
switch	O
for	O
the	O
lid	O
of	O
the	O
Duo	O
's	O
top-loading	O
CD-ROM	B-Device
drive	O
.	O
</s>
<s>
NEC	O
released	O
its	O
final	O
variation	O
of	O
the	O
PC	B-General_Concept
Engine	I-General_Concept
Duo	I-General_Concept
on	O
June	O
25	O
,	O
1994	O
.	O
</s>
<s>
TTI	O
released	O
the	O
TurboDuo	B-General_Concept
to	O
consumers	O
in	O
North	O
America	O
in	O
October	O
1992	O
,	O
at	O
a	O
retail	O
price	O
of	O
US	O
$299.99	O
.	O
</s>
<s>
The	O
price	O
was	O
,	O
in	O
part	O
,	O
a	O
consequence	O
of	O
the	O
relatively	O
high	O
cost	O
of	O
CD-ROM	B-Device
drive	O
manufacturing	O
.	O
</s>
<s>
Since	O
TTI	O
understood	O
that	O
the	O
price	O
was	O
too	O
high	O
for	O
many	O
people	O
in	O
their	O
target	O
market	O
,	O
they	O
included	O
a	O
booklet	O
of	O
coupons	O
for	O
TurboDuo	B-General_Concept
games	O
and	O
accessories	O
,	O
plus	O
several	O
pack-in	O
games	O
on	O
two	O
CD-ROMs	B-Device
:	O
Ys	B-Application
Book	I-Application
I	I-Application
&	I-Application
II	I-Application
(	O
1990	O
)	O
and	O
a	O
Super	O
CD	O
compilation	O
of	O
four	O
of	O
Hudson	O
Soft	O
's	O
more	O
popular	O
TurboGrafx-16	B-General_Concept
titles	O
:	O
Bonk	B-Application
's	I-Application
Adventure	I-Application
(	O
1989	O
)	O
,	O
Bonk	B-Application
's	I-Application
Revenge	I-Application
(	O
1991	O
)	O
,	O
Gate	B-Application
of	I-Application
Thunder	I-Application
(	O
1992	O
)	O
,	O
and	O
Bomberman	B-Application
(	O
1983	O
)	O
.	O
</s>
<s>
(	O
Bomberman	B-Application
was	O
hidden	O
in	O
an	O
Easter	O
egg	O
.	O
)	O
</s>
<s>
The	O
package	O
also	O
included	O
one	O
TurboChip	B-Device
game	O
:	O
Dungeon	B-Application
Explorer	I-Application
(	O
Hudson	O
Soft	O
1989	O
)	O
.	O
</s>
<s>
Later	O
,	O
TTI	O
replaced	O
Dungeon	B-Application
Explorer	I-Application
with	O
one	O
of	O
a	O
variety	O
of	O
TurboChip	B-Device
titles	O
,	O
such	O
as	O
Ninja	B-Application
Spirit	I-Application
(	O
Irem	O
1988	O
)	O
and	O
Final	B-Application
Lap	I-Application
Twin	I-Application
(	O
Namco	O
1989	O
)	O
.	O
</s>
<s>
With	O
the	O
release	O
of	O
the	O
TurboDuo	B-General_Concept
,	O
TTI	O
reduced	O
the	O
retail	O
price	O
of	O
the	O
TurboGrafx-CD	O
peripheral	O
for	O
the	O
TurboGrafx-16	B-General_Concept
to	O
$150.00	O
,	O
and	O
began	O
marketing	O
the	O
Super	O
System	O
Card	O
,	O
which	O
enabled	O
the	O
TurboGrafx-CD	O
to	O
play	O
the	O
new	O
Super	O
CD	O
games	O
.	O
</s>
<s>
The	O
Super	O
System	O
Card	O
is	O
programmed	O
with	O
the	O
updated	O
v3.0	O
BIOS	B-Operating_System
,	O
and	O
increases	O
the	O
TurboGrafx-16	B-General_Concept
'	O
s	O
RAM	B-Architecture
by	O
192	O
kilobytes	O
.	O
</s>
<s>
The	O
TurboGrafx-CD	O
requires	O
the	O
updated	O
BIOS	B-Operating_System
to	O
read	O
Super	O
CD	O
discs	O
,	O
and	O
the	O
additional	O
RAM	B-Architecture
to	O
run	O
the	O
software	O
capably	O
.	O
</s>
<s>
The	O
Super	O
System	O
Card	O
retailed	O
for	O
US$65	O
or	O
,	O
when	O
bundled	O
with	O
the	O
TurboDuo	B-General_Concept
's	O
Super	O
CD	O
compilation	O
disc	O
,	O
US$95	O
.	O
</s>
<s>
For	O
the	O
TurboDuo	B-General_Concept
marketing	O
campaign	O
,	O
TTI	O
used	O
a	O
character	O
called	O
"	O
Johnny	O
Turbo	O
"	O
.	O
</s>
<s>
In	O
1998	O
,	O
Jonathan	O
J	O
.	O
Burtenshaw	O
of	O
GameSpy	O
described	O
the	O
advertising	O
campaign	O
as	O
"	O
petty	O
"	O
and	O
"	O
overly	O
confrontational	O
,	O
"	O
and	O
conjectured	O
that	O
the	O
campaign	O
hurt	O
TurboDuo	B-General_Concept
sales	O
.	O
</s>
<s>
The	O
Hudson	B-General_Concept
Soft	I-General_Concept
HuC6280	I-General_Concept
is	O
a	O
modified	O
65C02	B-General_Concept
with	O
an	O
effective	O
clock	O
rate	O
of	O
1.79	O
or	O
7.16	O
MHz	O
(	O
switchable	O
by	O
software	O
)	O
.	O
</s>
<s>
It	O
is	O
capable	O
of	O
block	O
transfer	O
instructions	O
,	O
as	O
well	O
as	O
dedicated	O
move	O
instructions	O
for	O
communicating	O
with	O
the	O
TurboDuo	B-General_Concept
's	O
video	B-General_Concept
display	I-General_Concept
controller	I-General_Concept
,	O
the	O
HuC6270A	B-General_Concept
.	O
</s>
<s>
One	O
16-bit	O
HuC6270A	B-General_Concept
video	B-General_Concept
display	I-General_Concept
controller	I-General_Concept
(	O
VDC	O
)	O
.	O
</s>
<s>
The	O
HuC6270A	B-General_Concept
VDC	O
can	O
display	O
one	O
sprite	O
layer	O
.	O
</s>
<s>
The	O
HuC6270A	B-General_Concept
VDC	O
can	O
display	O
one	O
background	O
layer	O
.	O
</s>
<s>
TurboChip	B-Device
(	O
called	O
HuCard	B-Device
in	O
Japan	O
)	O
,	O
a	O
thin	O
,	O
card-like	O
ROM	B-Protocol
cartridge	I-Protocol
.	O
</s>
<s>
CD-ROM²	O
(	O
pronounced	O
"	O
CD-ROM-ROM	O
"	O
in	O
Japan	O
)	O
,	O
a	O
proprietary	O
CD-ROM-based	O
media	O
.	O
</s>
<s>
Unlike	O
the	O
TurboGrafx-CD	O
add-on	O
,	O
the	O
TurboDuo	B-General_Concept
could	O
play	O
standard	O
CD-ROM²	O
discs	O
,	O
as	O
well	O
Super	O
CD-ROM²	O
discs	O
,	O
without	O
the	O
need	O
of	O
a	O
System	O
Card	O
.	O
</s>
<s>
Early	O
CD-ROM²	O
games	O
released	O
in	O
North	O
America	O
were	O
branded	O
as	O
TurboGrafx-CD	O
discs	O
,	O
but	O
this	O
relabeling	O
fell	O
into	O
disuse	O
after	O
the	O
launch	O
of	O
the	O
TurboDuo	B-General_Concept
in	O
favor	O
of	O
keeping	O
the	O
CD-ROM²	O
and	O
Super	O
CD-ROM²	O
labeling	O
used	O
in	O
Japan	O
.	O
</s>
