<s>
The	O
is	O
a	O
home	B-Device
video	I-Device
game	I-Device
console	I-Device
manufactured	O
by	O
Sega	O
.	O
</s>
<s>
Developed	O
in	O
response	O
to	O
a	O
downturn	O
in	O
arcades	O
starting	O
in	O
1982	O
,	O
the	O
SG-1000	B-Operating_System
was	O
created	O
on	O
the	O
advice	O
of	O
Hayao	O
Nakayama	O
,	O
president	O
of	O
Sega	O
's	O
Japanese	O
arm	O
,	O
and	O
was	O
released	O
on	O
July	O
15	O
,	O
1983	O
,	O
the	O
same	O
day	O
that	O
Nintendo	O
released	O
the	O
Family	O
Computer	O
in	O
Japan	O
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
was	O
released	O
in	O
several	O
forms	O
,	O
including	O
the	O
SC-3000	O
computer	O
and	O
the	O
redesigned	O
SG-1000	B-Operating_System
II	I-Operating_System
released	O
in	O
1984	O
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
and	O
the	O
SC-3000	O
both	O
support	O
a	O
library	O
of	O
76	O
ROM	B-Protocol
cartridge	I-Protocol
games	O
and	O
29	O
Sega	B-Device
My	I-Device
Card	I-Device
games	O
.	O
</s>
<s>
A	O
third	B-Application
iteration	O
of	O
the	O
console	O
,	O
the	O
Sega	O
Mark	O
III	O
,	O
was	O
released	O
in	O
1985	B-Application
.	O
</s>
<s>
It	O
provided	O
an	O
improved	O
custom	O
video	O
display	O
processor	O
over	O
previous	O
iterations	O
and	O
served	O
as	O
the	O
basis	O
for	O
the	O
Master	O
System	O
in	O
1986	B-Application
,	O
Sega	O
's	O
first	O
internationally	O
released	O
console	O
.	O
</s>
<s>
All	O
SG-1000	B-Operating_System
games	O
are	O
fully	O
compatible	O
with	O
the	O
Mark	O
III	O
and	O
the	O
Japanese	O
version	O
of	O
the	O
Master	O
System	O
.	O
</s>
<s>
A	O
downturn	O
in	O
the	O
arcade	B-Application
business	I-Application
starting	O
in	O
1982	O
seriously	O
hurt	O
the	O
company	O
,	O
leading	O
Gulf	O
and	O
Western	O
to	O
sell	O
its	O
North	O
American	O
arcade	O
manufacturing	O
organization	O
and	O
the	O
licensing	O
rights	O
for	O
its	O
arcade	O
games	O
to	O
Bally	O
Manufacturing	O
.	O
</s>
<s>
The	O
company	O
retained	O
Sega	O
's	O
North	O
American	O
R&D	O
operation	O
,	O
as	O
well	O
as	O
its	O
Japanese	O
subsidiary	O
,	O
Sega	O
Enterprises	O
,	O
Ltd	O
.	O
With	O
its	O
arcade	B-Application
business	I-Application
in	O
decline	O
,	O
Sega	O
Enterprises	O
,	O
Ltd	O
.	O
president	O
Hayao	O
Nakayama	O
advocated	O
that	O
the	O
company	O
leverage	O
its	O
hardware	O
expertise	O
to	O
move	O
into	O
the	O
home	B-Device
console	I-Device
market	O
in	O
Japan	O
,	O
which	O
was	O
in	O
its	O
infancy	O
at	O
the	O
time	O
.	O
</s>
<s>
The	O
first	O
model	O
to	O
be	O
developed	O
was	O
the	O
SC-3000	O
,	O
a	O
computer	O
with	O
a	O
built-in	O
keyboard	O
,	O
but	O
when	O
Sega	O
learned	O
of	O
Nintendo	O
's	O
plans	O
to	O
release	O
a	O
games-only	O
console	O
,	O
they	O
began	O
developing	O
the	O
SG-1000	B-Operating_System
alongside	O
the	O
SC-3000	O
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
was	O
first	O
released	O
in	O
Japan	O
on	O
July	O
15	O
,	O
1983	O
,	O
at	O
¥	O
15,000	O
.	O
</s>
<s>
Though	O
Sega	O
themselves	O
only	O
released	O
the	O
SG-1000	B-Operating_System
in	O
Japan	O
,	O
rebranded	O
versions	O
were	O
released	O
in	O
several	O
other	O
markets	O
worldwide	O
.	O
</s>
<s>
Released	O
at	O
nearly	O
the	O
same	O
time	O
as	O
the	O
Japanese	O
version	O
,	O
the	O
SG-1000	B-Operating_System
was	O
released	O
in	O
Australia	O
through	O
John	O
Sands	O
Electronics	O
and	O
in	O
New	O
Zealand	O
by	O
Grandstand	O
Leisure	O
.	O
</s>
<s>
Despite	O
this	O
,	O
an	O
unauthorized	O
clone	B-General_Concept
system	O
known	O
as	O
the	O
Telegames	B-Device
Personal	I-Device
Arcade	I-Device
was	O
produced	O
and	O
made	O
available	O
in	O
the	O
United	O
States	O
and	O
Taiwan	O
,	O
and	O
is	O
able	O
to	O
play	O
SG-1000	B-Operating_System
and	O
ColecoVision	B-Device
games	O
.	O
</s>
<s>
An	O
additional	O
release	O
of	O
the	O
SG-1000	B-Operating_System
in	O
Taiwan	O
was	O
done	O
by	O
Aaronix	O
.	O
</s>
<s>
The	O
console	O
enjoyed	O
a	O
brief	O
period	O
of	O
popularity	O
in	O
Taiwan	O
before	O
the	O
market	O
was	O
taken	O
over	O
by	O
cheaper	O
Famicom	B-Operating_System
clones	I-Operating_System
.	O
</s>
<s>
Due	O
in	O
part	O
to	O
the	O
SG-1000	B-Operating_System
'	O
s	O
steadier	O
stream	O
of	O
releases	O
(	O
21	O
SG-1000	B-Operating_System
games	O
by	O
the	O
end	O
of	O
1983	O
,	O
as	O
compared	O
to	O
only	O
9	O
Famicom	O
games	O
)	O
,	O
and	O
in	O
part	O
to	O
a	O
recall	O
on	O
Famicom	O
units	O
necessitated	O
by	O
a	O
faulty	O
circuit	O
,	O
the	O
SG-1000	B-Operating_System
chalked	O
up	O
160,000	O
units	O
in	O
sales	O
in	O
1983	O
,	O
far	O
exceeding	O
Sega	O
's	O
projection	O
of	O
50,000	O
units	O
.	O
</s>
<s>
Former	O
Sega	O
consumer	O
hardware	O
development	O
head	O
Hideki	O
Sato	O
stated	O
that	O
because	O
Sega	O
had	O
not	O
predicted	O
the	O
SG-1000	B-Operating_System
would	O
sell	O
so	O
well	O
,	O
the	O
company	O
became	O
more	O
enamored	O
with	O
developing	O
video	B-Application
game	I-Application
consoles	I-Application
.	O
</s>
<s>
Despite	O
this	O
,	O
the	O
three	O
launch	O
games	O
,	O
all	O
of	O
which	O
were	O
ported	O
from	O
Sega	B-Application
's	I-Application
VIC	I-Application
dual-arcade	I-Application
board	I-Application
,	O
lacked	O
the	O
name	O
recognition	O
of	O
Famicom	O
launch	O
games	O
Donkey	B-Application
Kong	I-Application
,	O
Donkey	B-Application
Kong	I-Application
Jr.	I-Application
,	O
and	O
Popeye	B-Application
.	O
</s>
<s>
Following	O
the	O
buyout	O
,	O
Sega	O
released	O
another	O
console	O
,	O
the	O
SG-1000	B-Operating_System
II	I-Operating_System
,	O
on	O
July	O
31	O
,	O
1984	O
at	O
¥	O
15,000	O
.	O
</s>
<s>
It	O
is	O
sometimes	O
referred	O
to	O
as	O
the	O
"	O
SG-1000	B-Operating_System
Mark	O
II	O
"	O
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
II	I-Operating_System
replaced	O
the	O
hardwired	O
joystick	B-Device
with	O
two	O
detachable	O
joypads	O
.	O
</s>
<s>
Sato	O
disliked	O
the	O
original	O
cartridges	B-Protocol
,	O
saying	O
they	O
looked	O
like	O
"	O
small	O
black	O
tombstones	O
"	O
when	O
inserted	O
in	O
the	O
console	O
,	O
and	O
later	O
remarked	O
that	O
his	O
proudest	O
achievement	O
of	O
the	O
SG-1000	B-Operating_System
era	O
was	O
replacing	O
them	O
with	O
the	O
"	O
cheerier	O
"	O
,	O
pocket-sized	O
Sega	O
My	B-Device
Cards	I-Device
.	O
</s>
<s>
By	O
1984	O
,	O
the	O
Famicom	O
's	O
success	O
began	O
to	O
outpace	O
the	O
SG-1000	B-Operating_System
.	O
</s>
<s>
The	O
Famicom	O
had	O
more	O
advanced	O
hardware	O
,	O
allowing	O
it	O
to	O
perform	O
smoother	O
scrolling	O
and	O
more	O
colorful	O
sprites	O
,	O
and	O
Nintendo	O
boosted	O
its	O
games	O
library	O
by	O
courting	O
third-party	O
developers	O
,	O
whereas	O
Sega	O
was	O
less	O
than	O
eager	O
to	O
collaborate	O
with	O
the	O
same	O
companies	O
they	O
were	O
competing	O
with	O
in	O
arcades	O
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
was	O
also	O
coming	O
up	O
against	O
game	O
consoles	O
from	O
companies	O
including	O
Tomy	O
and	O
Bandai	O
.	O
</s>
<s>
This	O
would	O
result	O
in	O
the	O
release	O
of	O
the	O
Sega	O
Mark	O
III	O
in	O
Japan	O
in	O
1985	B-Application
,	O
which	O
later	O
became	O
the	O
Master	O
System	O
worldwide	O
.	O
</s>
<s>
The	O
last	O
cartridge	B-Protocol
released	O
was	O
Portrait	O
of	O
Loretta	O
on	O
February	O
18	O
,	O
1987	B-Application
.	O
</s>
<s>
In	O
2006	O
,	O
the	O
GameTap	B-Operating_System
subscription	O
gaming	O
service	O
added	O
an	O
emulator	B-Application
of	O
the	O
SG-1000	B-Operating_System
,	O
and	O
several	O
playable	O
titles	O
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
is	O
powered	O
by	O
an	O
8-bit	O
Zilog	B-General_Concept
Z80	I-General_Concept
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
running	O
at	O
3.58MHz	O
for	O
the	O
SG-1000	B-Operating_System
and	O
SG-1000	B-Operating_System
II	I-Operating_System
,	O
and	O
at	O
4MHz	O
for	O
the	O
SC-3000	O
.	O
</s>
<s>
Its	O
video	O
processor	O
is	O
a	O
Texas	B-Architecture
Instruments	I-Architecture
TMS9918A	I-Architecture
,	O
capable	O
of	O
displaying	O
up	O
to	O
16	O
colors	O
,	O
and	O
its	O
sound	O
processor	O
is	O
a	O
Texas	B-Device
Instruments	I-Device
SN76489	I-Device
.	O
</s>
<s>
The	O
system	O
includes	O
8kbit	O
(	O
1KB	O
)	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
The	O
controller	O
is	O
hardwired	O
to	O
the	O
system	O
in	O
the	O
original	O
model	O
,	O
and	O
detachable	O
in	O
the	O
SG-1000	B-Operating_System
II	I-Operating_System
.	O
</s>
<s>
Video	O
and	O
audio	O
output	O
are	O
supplied	O
through	O
an	O
RF	B-Algorithm
switch	I-Algorithm
.	O
</s>
<s>
Several	O
peripherals	O
exist	O
for	O
the	O
SG-1000	B-Operating_System
series	O
.	O
</s>
<s>
Multiple	O
controllers	B-Device
were	O
created	O
,	O
including	O
the	O
SJ-200	O
joystick	B-Device
attached	O
to	O
the	O
SG-1000	B-Operating_System
,	O
and	O
the	O
SJ-150	O
joypad	O
,	O
made	O
for	O
use	O
with	O
the	O
SG-1000	B-Operating_System
II	I-Operating_System
.	O
</s>
<s>
A	O
racing	O
wheel	O
known	O
as	O
the	O
SH-400	O
was	O
made	O
for	O
use	O
with	O
games	O
such	O
as	O
Monaco	B-Application
GP	I-Application
.	O
</s>
<s>
The	O
C-1000	O
Card	O
Catcher	O
,	O
sold	O
at	O
¥1	O
,	O
000	O
,	O
allows	O
players	O
to	O
play	O
Sega	B-Device
My	I-Device
Card	I-Device
titles	O
.	O
</s>
<s>
Additional	O
accessories	O
existed	O
solely	O
for	O
use	O
with	O
the	O
SC-3000	O
,	O
including	O
the	O
SR-1000	O
cassette	O
deck	O
,	O
the	O
SP-400	O
4-color	O
plotter	B-Operating_System
printer	I-Operating_System
,	O
and	O
the	O
SF-7000	O
expansion	O
device	O
which	O
adds	O
a	O
floppy	B-Device
disk	I-Device
drive	I-Device
and	O
additional	O
memory	O
.	O
</s>
<s>
Sega	O
's	O
software	O
library	O
for	O
the	O
SG-1000	B-Operating_System
and	O
SC-3000	O
comprises	O
42	O
game	B-Protocol
cartridges	I-Protocol
and	O
29	O
Sega	B-Device
My	I-Device
Card	I-Device
releases	O
that	O
required	O
the	O
Card	O
Catcher	O
add-on	O
.	O
</s>
<s>
There	O
were	O
also	O
26	O
educational	O
and	O
programming	O
cartridges	B-Protocol
for	O
the	O
SC-3000	O
that	O
could	O
only	O
be	O
played	O
on	O
the	O
SG-1000	B-Operating_System
with	O
the	O
SK-1100	O
keyboard	O
peripheral	O
.	O
</s>
<s>
Titles	O
for	O
the	O
system	O
include	O
Flicky	B-Application
,	O
Congo	B-Application
Bongo	I-Application
,	O
Sega-Galaga	B-Application
,	O
and	O
Girl	B-Application
's	I-Application
Garden	I-Application
,	O
the	O
first	O
video	O
game	O
programmed	O
by	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
developer	O
Yuji	O
Naka	O
.	O
</s>
<s>
Packaging	O
and	O
game	O
manuals	O
came	O
with	O
both	O
Japanese	O
and	O
English	O
text	O
until	O
1984	O
,	O
when	O
manuals	O
were	O
switched	O
to	O
Japanese	O
only	O
and	O
the	O
size	O
of	O
the	O
cartridge	B-Protocol
box	O
was	O
reduced	O
.	O
</s>
<s>
SC-3000/SG	O
-1000	O
games	O
were	O
continued	O
to	O
be	O
produced	O
after	O
the	O
launch	O
of	O
the	O
Mark	O
III	O
in	O
1985	B-Application
.	O
</s>
<s>
The	O
last	O
two	O
SC-3000/SG	O
-1000	O
cartridge	B-Protocol
games	O
were	O
The	B-Application
Castle	I-Application
in	O
1986	B-Application
and	O
Portrait	O
of	O
Loretta	O
in	O
1987	B-Application
.	O
</s>
<s>
The	O
final	O
Sega	B-Device
My	I-Device
Card	I-Device
game	O
for	O
the	O
SC-3000/SG	O
-1000	O
was	O
The	B-Application
Black	I-Application
Onyx	I-Application
,	O
also	O
in	O
1987	B-Application
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
console	O
series	O
(	O
including	O
the	O
Mark	O
III	O
)	O
sold	O
over	O
units	O
in	O
Japan	O
,	O
with	O
the	O
original	O
SG-1000	B-Operating_System
model	O
having	O
sold	O
400,000	O
units	O
in	O
Japan	O
.	O
</s>
<s>
The	O
SG-1000	B-Operating_System
made	O
little	O
impact	O
on	O
the	O
video	O
game	O
industry	O
,	O
but	O
has	O
been	O
recognized	O
for	O
being	O
Sega	O
's	O
first	O
video	B-Application
game	I-Application
console	I-Application
.	O
</s>
<s>
Retro	O
Gamer	O
writer	O
Damien	O
McFerran	O
said	O
it	O
was	O
an	O
"	O
abject	O
failure	O
"	O
,	O
but	O
called	O
it	O
and	O
the	O
SG-1000	B-Operating_System
II	I-Operating_System
"	O
the	O
Japanese	O
forefathers	O
of	O
the	O
Master	O
System	O
"	O
.	O
</s>
<s>
Writing	O
for	O
Wired	O
,	O
Chris	O
Kohler	O
criticized	O
the	O
poor	O
response	O
of	O
the	O
controller	O
's	O
joystick	B-Device
and	O
the	O
lack	O
of	O
an	O
RCA	B-Protocol
output	O
.	O
</s>
<s>
He	O
said	O
the	O
release	O
timing	O
hurt	O
its	O
success	O
;	O
"[al]though	O
its	O
graphics	O
were	O
of	O
better	O
quality	O
than	O
most	O
consoles	O
on	O
the	O
market	O
,	O
it	O
had	O
the	O
bad	O
luck	O
to	O
be	O
released	O
in	O
the	O
same	O
month	O
as	O
Nintendo	O
's	O
world-changing	O
Famicom	O
,	O
which	O
had	O
killer	O
apps	O
like	O
Donkey	B-Application
Kong	I-Application
and	O
could	O
run	O
circles	O
around	O
Sega	O
's	O
hardware.	O
"	O
</s>
<s>
By	O
contrast	O
,	O
Luke	O
Plunkett	O
of	O
Kotaku	O
recognized	O
that	O
"	O
while	O
all	O
this	O
makes	O
it	O
sound	O
like	O
the	O
SG-1000	B-Operating_System
was	O
a	O
bit	O
of	O
a	O
misfire	O
,	O
it	O
was	O
still	O
important	O
in	O
the	O
development	O
of	O
Sega	O
's	O
home	B-Device
console	I-Device
business.	O
"	O
</s>
<s>
Hideki	O
Sato	O
reflected	O
positively	O
on	O
the	O
innovations	O
in	O
the	O
development	O
of	O
the	O
SG-1000	B-Operating_System
,	O
but	O
admitted	O
that	O
the	O
console	O
had	O
limitations	O
because	O
of	O
how	O
new	O
the	O
market	O
was	O
and	O
that	O
Sega	O
was	O
inexperienced	O
in	O
developing	O
for	O
a	O
video	B-Application
game	I-Application
console	I-Application
at	O
the	O
time	O
.	O
</s>
