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= Atari_7800 =
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Introduction
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The Atari 7800 ProSystem, or simply the Atari 7800, is a home video
game console officially released by Atari Corporation in 1986 as the
successor to both the Atari 2600 and Atari 5200. It can run almost all
Atari 2600 cartridges, making it the first console with backward
compatibility. It shipped with a two button controller instead of the
2600-standard CX40 and 'Pole Position II' as the pack-in game. The
European model has a gamepad instead of a joystick. Most of the early
releases for the system are ports of 1981-1983 arcade video games. The
final wave of 7800 cartridges is closer in style to what was available
on other late 1980s consoles, such as 'Scrapyard Dog' and 'Midnight
Mutants'.
Designed by General Computer Corporation, the 7800 has graphics
hardware similar to early 1980s arcade video games and is a
significant improvement over Atari's previous consoles. It uses same
Television Interface Adaptor chip that launched with the Atari VCS in
1977 to generate two-channel audio. In an effort to prevent the flood
of poor quality games that contributed to the video game crash of
1983, cartridges had to be digitally signed by Atari.
The Atari 7800 was first announced by Atari, Inc. on May 21, 1984, but
a general release was shelved until May 1986 due to the sale of the
company. Atari Corporation dropped support for the 7800, along with
the 2600 and Atari 8-bit computers, on January 1, 1992.
History
======================================================================
The Atari 7800 ProSystem was the first console from Atari, Inc.
designed by an outside company: General Computer Corporation. It was
developed in 1983-84 with an intended mass market rollout in June
1984, but was canceled after the sale of the company to Tramel
Technology Ltd on July 2, 1984. The project was originally called the
Atari 3600.
With a background in creating arcade games such as 'Food Fight', GCC
designed the new system with a graphics architecture similar to arcade
machines of the time. The CPU is a slightly customized 6502 processor,
the Atari SALLY, running at 1.79 MHz. By some measures the 7800 is
more powerful, and by others less, than the 1983 Nintendo
Entertainment System. It uses the 2600's Television Interface Adaptor
chip, with the same restrictions, for generating two-channels of
audio.
Launch
========
The 7800 was announced on May 21, 1984. Thirteen games were announced
for the system's launch: 'Ms. Pac-Man', 'Pole Position II',
'Centipede', 'Joust', 'Dig Dug', 'Nile Flyer' (eventually released as
'Desert Falcon'), 'Robotron: 2084', 'Galaga', 'Food Fight',
'Ballblazer', 'Rescue on Fractalus!' (later canceled), 'Track &
Field', and 'Xevious'. It was a significant technological leap over
the Atari 2600 and Atari 5200.
On July 2, 1984, Warner Communications sold Atari's Consumer Division
to Jack Tramiel. All projects were halted during an initial evaluation
period. GCC had not been paid for their development of the 7800, and
Warner and Tramiel fought over who was accountable. In May 1985,
Tramiel relented and paid GCC. This led to additional negotiations
regarding the launch titles GCC had developed, then an effort to find
someone to lead their new video game division, which was completed in
November 1985. The original production run of the Atari 7800
languished in warehouses until it was introduced in January 1986.
The console was released nationwide in May 1986 for $79.95 with games
intended for the 7800's debut in 1984. It was aided by a marketing
campaign with a budget in the "low millions" according to Atari
Corporation officials. This was substantially less than the $9 million
spent by Sega and the $16 million spent by Nintendo. The keyboard and
high score cartridge planned by Warner were cancelled. The 7800
addressed many of the most common complaints with the preceding 5200,
including a smaller size, built-in backward compatibility, and an
improved controller design.
In February 1987, 'Computer Entertainer' reported that 100,000 Atari
7800 consoles had been sold in the United States, including those
which had been warehoused since 1984. This was less than the Master
System's 125,000 and the NES's 1.1 million. Games were slowly
released: 'Galaga' in August, followed by 'Xevious' in November. By
the end of 1986, the 7800 had 10 games, compared to Sega's 20 and
Nintendo's 36. Atari would sell over 1 million 7800 consoles by June
1988.
The Atari 7800 was released in the UK at the price of 70 pounds in
September 1989. It was supplied with two joypad controllers (C&VG,
issue 94, Sept.1989).
Discontinuation
=================
On January 1, 1992, Atari Corporation announced the end of production
and support for the 7800, 2600, and the 8-bit computer family
including the Atari XEGS. At least one game, an unreleased port of
'Toki', was worked on past this date. By the time of the
discontinuation, the Nintendo Entertainment System controlled 80% of
the North American market while Atari had 12%. In Europe, last stocks
of the 7800 were sold until summer/fall of 1995.
'Retro Gamer' magazine issue 132 reported that according to Atari UK
Marketing Manager Darryl Still, "it was very well stocked by European
retail; although it never got the consumer traction that the 2600 did,
I remember we used to sell a lot of units through mail order
catalogues and in the less affluent areas".
Technical specifications
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* CPU: Atari SALLY (custom variant of the 6502)
** 1.79 MHz, which drops to 1.19 MHz when the Television Interface
Adaptor or (6532 RAM-I/O-Timer) chips are accessed
** Unlike a standard 6502, 'SALLY' can be halted in a known state with
a single pin to let other devices control the bus.
** Sometimes referred to by Atari as "6502C", but not the same as the
official MOS Technology 6502C.
* RAM: 4 KB (2 6116 2Kx8 RAM ICs)
* ROM: built in 4 KB BIOS ROM, 48 KB Cartridge ROM space without bank
switching
* Graphics: MARIA custom chip
** Resolution: 160×240 (160×288 PAL) or 320×240 (320×288 PAL)
** Color palette: 256 (16 hues * 16 luma), different graphics modes
restricted the number of usable colors and the number of colors per
sprite
** Direct Memory Access (DMA)
** Graphics clock: 7.15 MHz
** Line buffer: 200 bytes (double buffering), 160 sprite pixels per
scanline, up to 30 sprites per scanline (without background), up to
100 sprites on screen
** Sprite/zone sizes: 4 to 160 width, height of 4, 8 or 16 pixels
** Colors per sprite: 1 to 12 (1 to 8 visible colors, 1 to 4
transparency bits)
* I/O: Joystick and console switch IO handled by 6532 RIOT and TIA
* Ports
**2 joystick ports
**cartridge port
**expansion connector
**power in
**RF output
* Sound: TIA as used in the 2600 for video and sound. In 7800 mode it
is only used for sound.
** At least two games include a POKEY sound chip for improved audio.
Graphics
==========
Graphics are generated by the custom MARIA chip, which uses an
approach common in contemporary arcade system boards and is different
from other second and third generation consoles. Instead of a limited
number of hardware sprites, MARIA treats everything as a sprite
described in a series of display lists. Each display list contains
pointers to graphics data and color and positioning information.
MARIA supports a palette of 256 colors and graphics modes which are
either 160 pixels wide or 320 pixels wide. While the 320 pixel modes
theoretically enable the 7800 to create games at higher resolution
than the 256 pixel wide graphics found in the Nintendo Entertainment
System and Master System, the processing demands of MARIA result in
most games using the 160 pixel mode.
Each sprite can have from 1 to 12 colors, with 3 colors plus
transparency being the most common. In this format, the sprite
references one of 8 palettes, where each palette holds 3 colors. The
background (visible when not covered by other objects) can also be
assigned a color. In total, 25 colors can appear on a scan line.
The graphics resolution, color palettes, and background color can be
adjusted between scan lines.
Sound
=======
The 7800 uses the TIA chip for two channel audio, the same chip used
in the 1977 Atari VCS, and the sound is of the same quality as that
system. To compensate, GCC's engineers allowed games to include a
POKEY audio chip in the cartridge. Only 'Ballblazer' and 'Commando' do
this.
GCC planned to make a low-cost, high performance sound chip, GUMBY,
which could also be placed in 7800 cartridges to enhance its sound
capabilities further. This project was cancelled when Atari was sold
to Jack Tramiel.
Digitally signed cartridges
=============================
Following the large number of low quality, third party games for the
Atari 2600, Atari required that cartridges for the 7800 be digitally
signed. When a cartridge is inserted into the system, the BIOS
generates a signature of the cartridge ROM and compares it to the one
stored on the cartridge. If they match, the console operates in 7800
mode, granting the game access to MARIA and other features, otherwise
the console operates as a 2600. This digital signature code is not
present in PAL 7800s, which use various heuristics to detect 2600
cartridges, due to export restrictions.
Backward compatibility
========================
The 7800's compatibility with the Atari 2600 is made possible by
including many of the same chips used in the 2600. When playing an
Atari 2600 game, the 7800 uses a Television Interface Adaptor chip to
generate graphics and sound. The processor is slowed to 1.19 MHz, to
mirror the performance of the 2600's 6507 chip. RAM is limited to 128
bytes and cartridge data is accessed in 4K blocks.
When in 7800 mode (signified by the appearance of the full-screen
Atari logo), the graphics are generated entirely by the MARIA graphics
processing unit. All system RAM is available and cartridge data is
accessed in larger 48K blocks. The system's SALLY 6502 runs at its
normal 1.79 MHz. The 2600 chips are used to generate sound and to
provide the interfaces to the controllers and console switches.
System revisions
==================
*Initial version: two joystick ports on lower front panel. Side
expansion port for upgrades and add-ons. Bundled with two CX24
Pro-Line joysticks, AC adapter, switchbox, RCA connecting cable, and
'Pole Position II' cartridge.
*Second revision: Slightly revised motherboard. Expansion port
connector removed from motherboard but is still etched. Shell has
indentation of where expansion port was to be.
*Third revision: Same as above but with only a small blemish on the
shell where the expansion port was.
Peripherals
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The Atari 7800 came bundled with the Atari Pro-Line Joystick, a
two-button controller with a joystick for movement. The Pro-Line was
developed for the 2600 and advertised in 1983, but delayed until Atari
proceeded with the 7800. The right fire button only works as a
separate fire button for certain 7800 games; otherwise, it duplicates
the left fire button, allowing either button to be used for 2600
games. While physically compatible, the 7800's controllers do not work
with the Sega Master System, and Sega's controllers are unable to use
the 7800's two-button mode.
In response to criticism over ergonomic issues with the Pro-Line
controllers, Atari later released a joypad controller with the
European 7800. Similar in style to controllers found on Nintendo and
Sega systems, it was not available in the United States.
The Atari XG-1 light gun, bundled with the Atari XEGS and also sold
separately, is compatible with the 7800. Atari released five 7800
light gun games: 'Alien Brigade', 'Barnyard Blaster', 'Crossbow',
'Meltdown', and 'Sentinel'.
Cancelled peripherals
=======================
After the acquisition of the Atari Consumer Division by Jack Tramiel
in 1984, several expansion options for the system were cancelled:
* The High Score Cartridge was designed to save high scores for up to
65 separate games. The cartridge was intended as a pass-through
device, similar to the later Game Genie. Nine games were programmed to
support the cartridge.
* The expansion port, to allow for the addition of a planned computer
keyboard and connection to laserdisc players and other peripherals,
was removed in the second and third revisions of the 7800.
* A dual joystick holder was designed for 'Robotron: 2084' and future
games like 'Battlezone', but not produced.
Games
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While the system can play the over 400 games for the Atari 2600, there
were only 59 official releases for the 7800. The lineup emphasized
high-quality versions of games from the golden age of arcade video
games. 'Pole Position II', 'Dig Dug', and 'Galaga', by the time of the
1986 launch, were three, four, and five years old, respectively. A
raster graphics version of 1979's 'Asteroids' was released in 1987. In
1988, Atari published a conversion of Nintendo's 'Donkey Kong', seven
years after the original arcade game and five years after the Atari
8-bit computer cartridge. Atari also marketed a line of games called
"Super Games" which were arcade and computer games previously not
playable on a home console such as 'One-On-One Basketball' and
'Impossible Mission'.
Eleven games were developed and sold by three third-party companies
under their own labels (Absolute Entertainment, Activision, and
Froggo) with the rest published by Atari Corporation. Most of the
games from Atari were developed by outside companies under contract.
Some NES games were developed by companies who had licensed their
title from a different arcade manufacturer. While the creator of the
NES version would be restricted from making a competitive version of
an NES game, the original arcade copyright holder was not precluded
from licensing out rights for a home version of an arcade game to
multiple systems. Through this loophole, Atari 7800 conversions of
'Mario Bros.', 'Double Dragon', 'Commando', 'Rampage', 'Xenophobe',
'Ikari Warriors', and 'Kung-Fu Master' were licensed and developed.
A final batch of games was released by Atari in 1990: 'Alien Brigade',
'Basketbrawl', 'Fatal Run', 'Meltdown', 'Midnight Mutants',
'MotorPsycho', 'Ninja Golf', 'Planet Smashers', and 'Scrapyard Dog'.
'Scrapyard Dog' was later released for the Atari Lynx.
Atari Flashback
=================
In 2004, the Infogrames-owned version of Atari released the Atari
Flashback console. It resembles a miniature Atari 7800 and has five
7800 and fifteen 2600 games built-in. Built using the NES-On-A-Chip
hardware instead of recreating the Atari 7800 hardware, it was
criticized for failing to properly replicate the actual gaming
experience. A subsequent 7800 project was cancelled after prototypes
were made.
Game development
==================
The digital signature long prevented aftermarket games from being
developed. The signing software was eventually found and released at
Classic Gaming Expo in 2001.
Several new Atari 7800 games such as 'Beef Drop', 'B*nQ', 'Combat
1990', 'CrazyBrix', 'Failsafe', and 'Santa Simon' have been released..
Source code
=============
In July 2009, the source code to 13 games, the operating system, and
Atari ST-hosted development tools, were released. Commented assembly
language source code was made available for 'Centipede', 'Commando',
'Crossbow', 'Desert Falcon', 'Dig Dug', 'Food Fight', 'Galaga', 'Hat
Trick', 'Joust', 'Ms. Pac-Man', 'Super Stunt Cycle', 'Robotron: 2084',
and 'Xevious'.
Atari 7800+
=============
In late 2024, Atari Inc. and Plaion released the 'Atari 7800+', a
microconsole designed as a smaller-scale replica of the 7800,
specifically the European model. It includes support for physical
cartridges of both the Atari 2600 and Atari 7800 through emulation. It
is effectively a variant of the Atari 2600+, which was introduced in
2023.
See also
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* History of Atari
* List of Atari 7800 games
* List of Atari 2600 games
External links
======================================================================
* [
http://www.atariage.com/software_search.html?SystemID=7800 AtariAge
– Comprehensive Atari 7800 database and information]
* [
http://www.atari7800.org Atari 7800 Information & Resources]
* [
http://www.atarimuseum.com/videogames/consoles/7800/7800menu/ Atari
Museum – History of the Atari 7800 ProSystem]
* [
http://7800.8bitdev.org/ Atari 7800 Development Wiki]
* [
https://gstanton.github.io/ProSystem1_3/ ProSystem emulator] for
Microsoft Windows
License
=========
All content on Gopherpedia comes from Wikipedia, and is licensed under CC-BY-SA
License URL:
http://creativecommons.org/licenses/by-sa/3.0/
Original Article:
http://en.wikipedia.org/wiki/Atari_7800
