<s>
The	O
Atari	B-General_Concept
7800	I-General_Concept
ProSystem	O
,	O
or	O
simply	O
the	O
Atari	B-General_Concept
7800	I-General_Concept
,	O
is	O
a	O
home	B-Device
video	I-Device
game	I-Device
console	I-Device
officially	O
released	O
by	O
Atari	O
Corporation	O
in	O
1986	O
as	O
the	O
successor	O
to	O
both	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
and	O
Atari	B-General_Concept
5200	I-General_Concept
.	O
</s>
<s>
It	O
can	O
run	O
almost	O
all	O
Atari	B-General_Concept
2600	I-General_Concept
cartridges	B-Protocol
,	O
making	O
it	O
one	O
of	O
the	O
first	O
consoles	O
with	O
backward	B-General_Concept
compatibility	I-General_Concept
.	O
</s>
<s>
It	O
shipped	O
with	O
a	O
different	O
model	O
of	O
joystick	B-Device
from	O
the	O
2600-standard	O
CX40	B-Device
and	O
Pole	B-Application
Position	I-Application
II	I-Application
as	O
the	O
pack-in	O
game	O
.	O
</s>
<s>
Most	O
of	O
the	O
announced	O
titles	O
at	O
launch	O
were	O
ports	O
of	O
1981	O
–	O
83	O
arcade	B-Application
video	I-Application
games	I-Application
.	O
</s>
<s>
Designed	O
by	O
General	O
Computer	O
Corporation	O
,	O
the	O
7800	O
has	O
significantly	O
improved	O
graphics	O
hardware	O
over	O
Atari	O
's	O
previous	O
consoles	O
,	O
but	O
the	O
same	O
Television	B-General_Concept
Interface	I-General_Concept
Adaptor	I-General_Concept
chip	O
that	O
launched	O
with	O
the	O
2600	O
in	O
1977	O
is	O
used	O
to	O
generate	O
audio	O
.	O
</s>
<s>
In	O
an	O
effort	O
to	O
prevent	O
the	O
flood	O
of	O
poor	O
quality	O
games	O
that	O
contributed	O
to	O
the	O
video	O
game	O
crash	O
of	O
1983	O
,	O
cartridges	B-Protocol
had	O
to	O
be	O
digitally	O
signed	O
by	O
Atari	O
.	O
</s>
<s>
The	O
Atari	B-General_Concept
7800	I-General_Concept
was	O
first	O
announced	O
by	O
Atari	O
,	O
Inc	O
.	O
on	O
May	O
21	O
,	O
1984	O
,	O
but	O
a	O
general	O
release	O
was	O
shelved	O
until	O
May	O
1986	O
due	O
to	O
the	O
sale	O
of	O
the	O
company	O
.	O
</s>
<s>
Atari	O
Corporation	O
dropped	O
support	O
for	O
the	O
7800	O
,	O
along	O
with	O
the	O
2600	O
and	O
the	O
Atari	B-Device
8-bit	I-Device
family	I-Device
,	O
on	O
January	O
1	O
,	O
1992	O
.	O
</s>
<s>
Atari	O
had	O
been	O
facing	O
pressure	O
from	O
Coleco	O
and	O
its	O
ColecoVision	B-Device
console	O
,	O
which	O
supported	O
graphics	O
that	O
more	O
closely	O
mirrored	O
arcade	O
games	O
of	O
the	O
time	O
than	O
either	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
or	O
5200	O
.	O
</s>
<s>
The	O
Atari	B-General_Concept
5200	I-General_Concept
(	O
released	O
as	O
a	O
successor	O
to	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
)	O
was	O
criticized	O
for	O
not	O
being	O
able	O
to	O
play	O
2600	B-Application
games	I-Application
without	O
an	O
adapter	O
.	O
</s>
<s>
The	O
Atari	B-General_Concept
7800	I-General_Concept
ProSystem	O
was	O
the	O
first	O
console	O
from	O
Atari	O
,	O
Inc	O
.	O
designed	O
by	O
an	O
outside	O
company	O
,	O
General	O
Computer	O
Corporation	O
.	O
</s>
<s>
With	O
a	O
background	O
in	O
creating	O
arcade	O
games	O
such	O
as	O
Food	B-Application
Fight	I-Application
,	O
GCC	O
designed	O
the	O
new	O
system	O
with	O
a	O
graphics	O
architecture	O
similar	O
to	O
arcade	O
machines	O
of	O
the	O
time	O
.	O
</s>
<s>
The	O
CPU	O
is	O
a	O
slightly	O
customized	O
6502	B-General_Concept
processor	I-General_Concept
,	O
the	O
Atari	B-Device
SALLY	I-Device
,	O
running	O
at	O
1.79MHz	O
.	O
</s>
<s>
It	O
uses	O
the	O
2600	O
's	O
Television	B-General_Concept
Interface	I-General_Concept
Adaptor	I-General_Concept
chip	O
,	O
with	O
the	O
same	O
restrictions	O
,	O
for	O
generating	O
two-channels	O
of	O
audio	O
.	O
</s>
<s>
Thirteen	O
games	O
were	O
announced	O
for	O
the	O
system	O
's	O
launch	O
:	O
Ms.	B-Application
Pac-Man	I-Application
,	O
Pole	B-Application
Position	I-Application
II	I-Application
,	O
Centipede	B-Application
,	O
Joust	B-Application
,	O
Dig	B-Application
Dug	I-Application
,	O
Nile	O
Flyer	O
(	O
eventually	O
released	O
as	O
Desert	B-Application
Falcon	I-Application
)	O
,	O
Robotron	B-Application
:	I-Application
2084	I-Application
,	O
Galaga	B-Application
,	O
Food	B-Application
Fight	I-Application
,	O
Ballblazer	B-Application
,	O
Rescue	O
on	O
Fractalus	O
!,	O
Track	B-Application
&	I-Application
Field	I-Application
,	O
and	O
Xevious	B-Application
.	O
</s>
<s>
The	O
original	O
production	O
run	O
of	O
the	O
Atari	B-General_Concept
7800	I-General_Concept
languished	O
in	O
warehouses	O
until	O
it	O
was	O
introduced	O
in	O
January	O
1986	O
.	O
</s>
<s>
The	O
keyboard	O
and	O
high	O
score	O
cartridge	B-Protocol
planned	O
by	O
Warner	O
were	O
cancelled	O
.	O
</s>
<s>
In	O
February	O
1987	O
,	O
Computer	O
Entertainer	O
reported	O
that	O
100,000	O
Atari	B-General_Concept
7800	I-General_Concept
consoles	O
had	O
been	O
sold	O
in	O
the	O
United	O
States	O
,	O
including	O
those	O
which	O
had	O
been	O
warehoused	O
since	O
1984	O
.	O
</s>
<s>
Galaga	B-Application
in	O
August	O
was	O
followed	O
by	O
Xevious	B-Application
in	O
November	O
.	O
</s>
<s>
On	O
January	O
1	O
,	O
1992	O
,	O
Atari	O
Corporation	O
announced	O
the	O
end	O
of	O
production	O
and	O
support	O
for	O
the	O
7800	O
,	O
2600	O
,	O
and	O
the	O
8-bit	O
computer	O
family	O
including	O
the	O
Atari	B-General_Concept
XEGS	I-General_Concept
.	O
</s>
<s>
At	O
least	O
one	O
game	O
,	O
an	O
unreleased	O
port	O
of	O
Toki	B-Application
,	O
was	O
worked	O
on	O
past	O
this	O
date	O
.	O
</s>
<s>
Unlike	O
a	O
standard	O
6502	B-General_Concept
,	O
SALLY	B-Device
can	O
be	O
halted	O
in	O
a	O
known	O
state	O
with	O
a	O
single	O
pin	O
to	O
let	O
other	O
devices	O
control	O
the	O
bus	O
.	O
</s>
<s>
Sound	O
:	O
TIA	B-General_Concept
as	O
used	O
in	O
the	O
2600	O
for	O
video	O
and	O
sound	O
.	O
</s>
<s>
At	O
least	O
two	O
games	O
include	O
a	O
POKEY	B-Device
sound	O
chip	O
for	O
improved	O
audio	O
.	O
</s>
<s>
Graphics	O
are	O
generated	O
by	O
the	O
custom	O
MARIA	O
chip	O
,	O
which	O
uses	O
an	O
approach	O
common	O
in	O
contemporary	O
arcade	O
system	O
boards	O
and	O
is	O
different	O
from	O
other	O
second	B-Application
and	O
third	B-Application
generation	I-Application
consoles	O
.	O
</s>
<s>
In	O
total	O
,	O
25	O
colors	O
can	O
appear	O
on	O
a	O
scan	B-Algorithm
line	I-Algorithm
.	O
</s>
<s>
The	O
graphics	O
resolution	O
,	O
color	O
palettes	O
,	O
and	O
background	O
color	O
can	O
be	O
adjusted	O
between	O
scan	B-Algorithm
lines	I-Algorithm
.	O
</s>
<s>
The	O
7800	O
uses	O
the	O
TIA	B-General_Concept
chip	O
for	O
two	O
channel	O
audio	O
,	O
the	O
same	O
chip	O
used	O
in	O
the	O
1977	O
Atari	B-General_Concept
VCS	I-General_Concept
,	O
and	O
the	O
sound	O
is	O
of	O
the	O
same	O
quality	O
as	O
that	O
system	O
.	O
</s>
<s>
To	O
compensate	O
,	O
GCC	O
's	O
engineers	O
allowed	O
games	O
to	O
include	O
a	O
POKEY	B-Device
audio	I-Device
chip	I-Device
in	O
the	O
cartridge	B-Protocol
.	O
</s>
<s>
Only	O
Ballblazer	B-Application
and	O
Commando	B-Application
do	O
this	O
.	O
</s>
<s>
GCC	O
planned	O
to	O
make	O
a	O
low-cost	O
,	O
high	O
performance	O
sound	O
chip	O
,	O
GUMBY	O
,	O
which	O
could	O
also	O
be	O
placed	O
in	O
7800	O
cartridges	B-Protocol
to	O
enhance	O
its	O
sound	O
capabilities	O
further	O
.	O
</s>
<s>
Following	O
the	O
large	O
number	O
of	O
low	O
quality	O
,	O
third	B-Application
party	O
games	O
for	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
,	O
Atari	O
required	O
that	O
cartridges	B-Protocol
for	O
the	O
7800	O
be	O
digitally	O
signed	O
.	O
</s>
<s>
When	O
a	O
cartridge	B-Protocol
is	O
inserted	O
into	O
the	O
system	O
,	O
the	O
BIOS	B-Operating_System
generates	O
a	O
signature	O
of	O
the	O
cartridge	B-Protocol
ROM	B-Device
and	O
compares	O
it	O
to	O
the	O
one	O
stored	O
on	O
the	O
cartridge	B-Protocol
.	O
</s>
<s>
This	O
digital	O
signature	O
code	O
is	O
not	O
present	O
in	O
PAL	B-Language
7800s	O
,	O
which	O
use	O
various	O
heuristics	O
to	O
detect	O
2600	O
cartridges	B-Protocol
,	O
due	O
to	O
export	O
restrictions	O
.	O
</s>
<s>
The	O
7800	O
's	O
compatibility	O
with	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
is	O
made	O
possible	O
by	O
including	O
many	O
of	O
the	O
same	O
chips	O
used	O
in	O
the	O
2600	O
.	O
</s>
<s>
When	O
playing	O
an	O
Atari	B-General_Concept
2600	I-General_Concept
game	O
,	O
the	O
7800	O
uses	O
a	O
Television	B-General_Concept
Interface	I-General_Concept
Adapter	I-General_Concept
chip	O
to	O
generate	O
graphics	O
and	O
sound	O
.	O
</s>
<s>
RAM	B-Architecture
is	O
limited	O
to	O
128	O
bytes	O
and	O
cartridge	B-Protocol
data	O
is	O
accessed	O
in	O
4K	O
blocks	O
.	O
</s>
<s>
All	O
system	O
RAM	B-Architecture
is	O
available	O
and	O
cartridge	B-Protocol
data	O
is	O
accessed	O
in	O
larger	O
48K	O
blocks	O
.	O
</s>
<s>
The	O
system	O
's	O
SALLY	B-Device
6502	B-General_Concept
runs	O
at	O
its	O
normal	O
1.79MHz	O
.	O
</s>
<s>
Initial	O
version	O
:	O
two	O
joystick	B-Device
ports	O
on	O
lower	O
front	O
panel	O
.	O
</s>
<s>
Bundled	O
with	O
two	O
CX24	O
Pro-Line	O
joysticks	B-Device
,	O
AC	O
adapter	O
,	O
switchbox	O
,	O
RCA	O
connecting	O
cable	O
,	O
and	O
Pole	B-Application
Position	I-Application
II	I-Application
cartridge	B-Protocol
.	O
</s>
<s>
Second	B-Application
revision	O
:	O
Slightly	O
revised	O
motherboard	O
.	O
</s>
<s>
Third	B-Application
revision	O
:	O
Same	O
as	O
above	O
but	O
with	O
only	O
a	O
small	O
blemish	O
on	O
the	O
shell	O
where	O
the	O
expansion	O
port	O
was	O
.	O
</s>
<s>
The	O
Atari	B-General_Concept
7800	I-General_Concept
came	O
bundled	O
with	O
the	O
Atari	O
Pro-Line	O
Joystick	B-Device
,	O
a	O
two-button	O
controller	O
with	O
a	O
joystick	B-Device
for	O
movement	O
.	O
</s>
<s>
The	O
right	O
fire	O
button	O
only	O
works	O
as	O
a	O
separate	O
fire	O
button	O
for	O
certain	O
7800	B-Application
games	I-Application
;	O
otherwise	O
,	O
it	O
duplicates	O
the	O
left	O
fire	O
button	O
,	O
allowing	O
either	O
button	O
to	O
be	O
used	O
for	O
2600	B-Application
games	I-Application
.	O
</s>
<s>
The	O
Atari	B-Device
XG-1	I-Device
light	I-Device
gun	I-Device
,	O
bundled	O
with	O
the	O
Atari	B-General_Concept
XEGS	I-General_Concept
and	O
also	O
sold	O
separately	O
,	O
is	O
compatible	O
with	O
the	O
7800	O
.	O
</s>
<s>
Atari	O
released	O
five	O
7800	O
light	O
gun	O
games	O
:	O
Alien	B-Application
Brigade	I-Application
,	O
Barnyard	B-Application
Blaster	I-Application
,	O
Crossbow	B-Application
,	O
Meltdown	B-Application
,	O
and	O
Sentinel	O
.	O
</s>
<s>
The	O
High	O
Score	O
Cartridge	B-Protocol
was	O
designed	O
to	O
save	O
high	O
scores	O
for	O
up	O
to	O
65	O
separate	O
games	O
.	O
</s>
<s>
The	O
cartridge	B-Protocol
was	O
intended	O
as	O
a	O
pass-through	O
device	O
,	O
similar	O
to	O
the	O
later	O
Game	B-Device
Genie	I-Device
.	O
</s>
<s>
Nine	O
games	O
were	O
programmed	O
to	O
support	O
the	O
cartridge	B-Protocol
.	O
</s>
<s>
The	O
expansion	O
port	O
,	O
to	O
allow	O
for	O
the	O
addition	O
of	O
a	O
planned	O
computer	O
keyboard	O
and	O
connection	O
to	O
laserdisc	O
players	O
and	O
other	O
peripherals	O
,	O
was	O
removed	O
in	O
the	O
second	B-Application
and	O
third	B-Application
revisions	O
of	O
the	O
7800	O
.	O
</s>
<s>
A	O
dual	O
joystick	B-Device
holder	O
was	O
designed	O
for	O
Robotron	B-Application
:	I-Application
2084	I-Application
and	O
future	O
games	O
like	O
Battlezone	B-Application
,	O
but	O
not	O
produced	O
.	O
</s>
<s>
While	O
the	O
system	O
can	O
play	O
the	O
over	O
400	O
games	O
for	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
,	O
there	O
were	O
only	O
59	O
official	O
releases	O
for	O
the	O
7800	O
.	O
</s>
<s>
The	O
lineup	O
emphasized	O
high-quality	O
versions	O
of	O
games	O
from	O
the	O
golden	O
age	O
of	O
arcade	B-Application
video	I-Application
games	I-Application
.	O
</s>
<s>
Pole	B-Application
Position	I-Application
II	I-Application
,	O
Dig	B-Application
Dug	I-Application
,	O
and	O
Galaga	B-Application
,	O
by	O
the	O
time	O
of	O
the	O
1986	O
launch	O
,	O
were	O
three	O
,	O
four	O
,	O
and	O
five	O
years	O
old	O
,	O
respectively	O
.	O
</s>
<s>
A	O
raster	O
graphics	O
version	O
of	O
1979	O
's	O
Asteroids	B-Application
was	O
released	O
in	O
1987	O
.	O
</s>
<s>
In	O
1988	O
,	O
Atari	O
published	O
a	O
conversion	O
of	O
Nintendo	O
's	O
Donkey	B-Application
Kong	I-Application
,	O
seven	O
years	O
after	O
the	O
original	O
arcade	O
game	O
and	O
five	O
years	O
after	O
the	O
Atari	B-Device
8-bit	I-Device
family	I-Device
cartridge	B-Protocol
.	O
</s>
<s>
Eleven	O
games	O
were	O
developed	O
and	O
sold	O
by	O
three	O
third-party	O
companies	O
under	O
their	O
own	O
labels	O
(	O
Absolute	O
Entertainment	O
,	O
Activision	O
,	O
and	O
Froggo	B-Application
)	O
with	O
the	O
rest	O
published	O
by	O
Atari	O
Corporation	O
.	O
</s>
<s>
Through	O
this	O
loophole	O
,	O
Atari	B-General_Concept
7800	I-General_Concept
conversions	O
of	O
Mario	O
Bros.	O
,	O
Double	B-Application
Dragon	I-Application
,	O
Commando	B-Application
,	O
Rampage	B-Application
,	O
Xenophobe	B-Application
,	O
Ikari	B-Application
Warriors	I-Application
,	O
and	O
Kung-Fu	B-Application
Master	I-Application
were	O
licensed	O
and	O
developed	O
.	O
</s>
<s>
A	O
final	O
batch	O
of	O
games	O
was	O
released	O
by	O
Atari	O
in	O
1990	O
:	O
Alien	B-Application
Brigade	I-Application
,	O
Basketbrawl	B-Application
,	O
Fatal	B-Application
Run	I-Application
,	O
Meltdown	B-Application
,	O
Midnight	B-Application
Mutants	I-Application
,	O
MotorPsycho	O
,	O
Ninja	B-Application
Golf	I-Application
,	O
Planet	O
Smashers	O
,	O
and	O
Scrapyard	B-Application
Dog	I-Application
.	O
</s>
<s>
Scrapyard	B-Application
Dog	I-Application
was	O
later	O
released	O
for	O
the	O
Atari	B-General_Concept
Lynx	I-General_Concept
.	O
</s>
<s>
It	O
resembles	O
a	O
miniature	O
Atari	B-General_Concept
7800	I-General_Concept
and	O
has	O
five	O
7800	O
and	O
fifteen	O
2600	B-Application
games	I-Application
built-in	O
.	O
</s>
<s>
Built	O
using	O
the	O
NES-On-A-Chip	B-Operating_System
hardware	O
instead	O
of	O
recreating	O
the	O
Atari	B-General_Concept
7800	I-General_Concept
hardware	O
,	O
it	O
was	O
criticized	O
for	O
failing	O
to	O
properly	O
replicate	O
the	O
actual	O
gaming	O
experience	O
.	O
</s>
<s>
Several	O
new	O
Atari	B-General_Concept
7800	I-General_Concept
games	O
such	O
as	O
Beef	O
Drop	O
,	O
B*nQ	O
,	O
Combat	O
1990	O
,	O
CrazyBrix	O
,	O
Failsafe	O
,	O
and	O
Santa	O
Simon	O
have	O
been	O
released	O
..	O
</s>
<s>
The	O
source	O
code	O
for	O
13	O
games	O
,	O
the	O
operating	O
system	O
,	O
and	O
the	O
development	O
tools	O
which	O
run	O
on	O
the	O
Atari	B-Device
ST	I-Device
were	O
discovered	O
in	O
a	O
dumpster	O
behind	O
the	O
Atari	O
building	O
in	O
Sunnyvale	O
,	O
California	O
.	O
</s>
<s>
Commented	O
assembly	B-Language
language	I-Language
source	O
code	O
was	O
made	O
available	O
for	O
Centipede	B-Application
,	O
Commando	B-Application
,	O
Crossbow	B-Application
,	O
Desert	B-Application
Falcon	I-Application
,	O
Dig	B-Application
Dug	I-Application
,	O
Food	B-Application
Fight	I-Application
,	O
Galaga	B-Application
,	O
Hat	O
Trick	O
,	O
Joust	B-Application
,	O
Ms.	B-Application
Pac-Man	I-Application
,	O
Super	O
Stunt	B-Application
Cycle	I-Application
,	O
Robotron	B-Application
:	I-Application
2084	I-Application
,	O
and	O
Xevious	B-Application
.	O
</s>
