The Atari joystick port is a
computer port used to connect various gaming controllers to
game console
A video game console is an electronic device that outputs a video signal or image to display a video game that can be played with a game controller. These may be home consoles, which are generally placed in a permanent location connected to a t ...
and
home computer systems in the 1970s to the 1990s. It was originally introduced on the
Atari 2600
The Atari 2600, initially branded as the Atari Video Computer System (Atari VCS) from its release until November 1982, is a home video game console developed and produced by Atari, Inc. Released in September 1977, it popularized microprocessor- ...
in 1977 and then used on the
Atari 400 and 800 in 1979. It went cross-platform with the
VIC-20
The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit home computer that was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore's first personal computer, the PE ...
in 1981, and was then used on many following machines from both companies, as well as a growing list of 3rd party machines like the
MSX platform and various
Sega
is a Japanese multinational corporation, multinational video game and entertainment company headquartered in Shinagawa, Tokyo. Its international branches, Sega of America and Sega Europe, are headquartered in Irvine, California and London, r ...
consoles.
The port, based on the inexpensive 9-pin
D-connector
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smallest connectors used on computer systems.
Description, no ...
, became a ''de facto'' standard through the 1980s and into the 1990s, supported by a wide variety of joysticks and other devices, most commonly
paddle controller
A paddle is a game controller with a round ''wheel'' and one or more ''fire buttons'', where the wheel is typically used to control movement of the player object along one axis of the video screen. A paddle controller rotates through a fixed arc ( ...
s,
light pen
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display.
It allows the user to point to displayed objects or draw on the screen in a similar way to a tou ...
s and
computer mice
A computer mouse (plural mice, sometimes mouses) is a hand-held pointing device that detects two-dimensional space, two-dimensional motion relative to a surface. This motion is typically translated into the motion of a pointer (user interface ...
. The standard was so engrained that it led to devices like the
Kempston Interface
Kempston Micro Electronics was an electronics company based in Kempston, Bedfordshire, England specialising in computer joysticks and related home computer peripherals during the 1980s.
The Kempston Interface, a peripheral which allowed a joys ...
that allowed Atari joysticks to be used on the
ZX Spectrum
The ZX Spectrum () is an 8-bit computing, 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer.
Referred to during development as t ...
. The port was also used for all sorts of non-gaming roles, including the
AtariLab interface,
modem
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulati ...
s,
numeric keypad
A numeric keypad, number pad, numpad, or ten key,
is the palm-sized, usually-17-key section of a standard computer keyboard, usually on the far right. It provides calculator-style efficiency for entering numbers. The idea of a 10-key nu ...
s, and even a video expansion card.
By the mid-1990s, the last home computer and game console models using Atari ports - often for both joystick and mouse - were exiting from the markets. IBM PC compatible computers which did not have Atari joystick ports replaced other home computer models, and console manufacturers such as Sega switched to other type of ports.
History
![Atari-2600-Woody-BR](https://upload.wikimedia.org/wikipedia/commons/4/4a/Atari-2600-Woody-BR.jpg)
The Atari 2600 developed out of an effort to address problems Atari found when releasing their first home video game console, ''
Pong
''Pong'' is a table tennis–themed twitch arcade sports video game, featuring simple two-dimensional graphics, manufactured by Atari and originally released in 1972. It was one of the earliest arcade video games; it was created by Allan Alcor ...
''. Although successful, ''Pong'' was an expensive system to design, and was dedicated solely to one game. It would be much more practical to have a machine that could run multiple games. The list of games it would need to support included ''Pong'' variations, and ''
Tank
A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and good battlefield mobility provided by tracks and a powerful engin ...
''. It was the desire to run these two games that led to the need for some sort of flexible input system; ''Pong'' used analog paddle controllers, while ''Tank'' used dual digital (on/off) joysticks.
Arcade game
An arcade game or coin-op game is a coin-operated entertainment machine typically installed in public businesses such as restaurants, bars and amusement arcades. Most arcade games are presented as primarily games of skill and include arcade v ...
s of the era generally used paddles, joysticks or a unique sort of steering wheel controller that was spun, entirely unlike a real car.
Development of the 2600 was strictly a paper project until September 1975, when the
MOS Technology 6502
The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small t ...
processor was released. The 6502 offered the right combinations of features, performance and price that made a console using
ROM cartridge
A ROM cartridge, usually referred to in context simply as a cartridge, cart, or card, is a replaceable part designed to be connected to a consumer electronics device such as a home computer, video game console or, to a lesser extent, electroni ...
s for program storage practical for the first time. Now that such a machine seemed like a real possibility, the design team at
Cyan Engineering Cyan Engineering was an American computer engineering company located in Grass Valley, California.https://www.youtube.com/watch?v=bfFGrQLuY8s Atari's Cyan Engineering - Splendor in the Grass documentary It was founded by Steve Mayer and Larry Emmons ...
began serious development.
As part of this effort,
Joe Decuir
Joseph C. Decuir is an American fellow of the Institute of Electrical and Electronics Engineers (IEEE) who was nominated in 2015 for contributions to computer graphics and video games.
Early computer games
Decuir was nominated to Fellowship in th ...
began development of an I/O system based primarily on the
MOS Technology 6532
The 6532 RAM-I/O-Timer (RIOT) was an integrated circuit made by MOS Technology, as well as second sources such as Rockwell. It incorporated 128 bytes of static RAM, two bidirectional 8-bit digital input/output ports, and a Programmable interv ...
, which included 8-bit I/O ports as well as the hardware needed to control memory refresh and similar housekeeping tasks. Ultimately, the design used five of the I/O ports (pins) to control the various front-panel switches, and four each for the two controllers. Additionally, the
TIA
TIA or Tia may refer to:
Aviation
* Tampa International Airport, US, IATA code TPA
* Texas International Airlines, US, ICAO code
* Tirana International Airport Nënë Tereza, Albania, IATA code
* Trans International Airlines, former U.S. airl ...
, whose primary task was sound and video, was used to handle timing-based controllers like paddles and light pens. The physical interface was the 9-pin D-sub connector, which was already relatively common for reduced pin-count
serial port
In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. ...
s on the
Apple II
The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-m ...
and
S-100 bus
The S-100 bus or Altair bus, IEEE 696-1983 ''(withdrawn)'', is an early computer bus designed in 1974 as a part of the Altair 8800. The bus was the first industry standard expansion bus for the microcomputer industry. computers, consisting of ...
machines. Each of the pins in the connector went directly to the appropriate pin on the associated chip.
The 2600 was released in 1977, shipping with both the paddle controllers and a single joystick. The port allowed the 2600 to more easily support a wider variety of games, not just specific games but entire genres. Most game consoles before the Atari had paddle controllers, even detachable ones in the case of the
Fairchild Channel F
The Fairchild Channel F, short for "Channel Fun", is a video game console, the first to be based on a microprocessor and to use ROM cartridges instead of having games built-in. It was released by Fairchild Camera and Instrument in November 1976 a ...
and
Magnavox Odyssey
The Magnavox Odyssey is the first commercial home video game console. The hardware was designed by a small team led by Ralph H. Baer at Sanders Associates, while Magnavox completed development and released it in the United States in September ...
. But the joystick was new, and quickly garnered praise as it allowed direct input into a number of games that would otherwise be difficult to control using a paddle. The joystick has been called "the pinnacle of home entertainment controllers in its day".
After the release of the 2600, the Cyan team immediately turned to the development of its replacement, aiming for the 1979 time frame. As the "standard" was already set on the 2600, the new machines naturally used the same controller interface, although the details of the systems used to read it changed. As 1979 approached the
home computer market emerged, and Atari repositioned the new system as the 400 and 800, the first members of the
Atari 8-bit family
The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 as the Atari 400 and Atari 800. The series was successively upgraded to Atari 1200XL , Atari 600XL, Atari 800XL, Atari 65XE, Atari 130XE, Atari 800XE, ...
. This meant the standard now crossed the line between consoles and computers.
The port design was extremely flexible, and over time saw not only a wide variety of input devices, but output as well. Included among the non-controller devices was the
AtariLab system that allowed users to plug in various laboratory devices like digital thermometers, the 300 baud MPP-1000C modem, and even Atari's own 80-column adaptor for the 8-bit series, the XEP80. It was widely used in the home-brew market as a lightweight input device, and articles on how to build various adapters were common.
Commodore included an Atari joystick port with the
VIC-20
The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit home computer that was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore's first personal computer, the PE ...
computer. Atari had patents on the joystick and won an injunction against Commodore, which produced an almost identical "imitation" joystick for the VIC-20, but held no patents on the port itself. By the time Commodore began development of the VIC-20 millions of controllers compatible with the port were in the market.
The Atari joystick port rapidly proliferated across the industry. Hundreds of new devices using the system cropped up over time, including
trackball
A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down ball mouse with an exposed protruding ball. Users roll the ball to position the on-s ...
s and other advanced inputs. The standard became so widely used that almost every 8-bit machine released after 1982 used it, and adapters were available for those that did not, like the
Apple II
The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-m ...
and
Sinclair ZX Spectrum
The ZX Spectrum () is an 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer.
Referred to during development as the ''ZX81 Colour ...
. One
TI-99/4A
The TI-99/4 and TI-99/4A are home computers released by Texas Instruments in 1979 and 1981, respectively. Based on the Texas Instruments TMS9900 microprocessor originally used in minicomputers, the TI-99/4 was the first 16-bit home computer. ...
reseller reported that its best-selling product was the Atari joystick adapter.
The port moved to 16/32-bit machines like the
Atari ST
The Atari ST is a line of personal computers from Atari Corporation and the successor to the Atari 8-bit family. The initial model, the Atari 520ST, had limited release in April–June 1985 and was widely available in July. It was the first pers ...
and
Commodore Amiga
Amiga is a family of personal computers introduced by Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly improved graphi ...
as well.
The introduction of the
Nintendo Entertainment System
The Nintendo Entertainment System (NES) is an 8-bit third-generation home video game console produced by Nintendo. It was first released in Japan in 1983 as the commonly known as the The NES, a redesigned version, was released in America ...
was the first widespread example of a gaming system in that era that did not use the Atari design, its
D-pad
A D-pad (short for directional pad or digital pad; officially referred to by Nintendo as a +Control Pad) is a flat, usually thumb-operated, often digital, four-way directional control with one button on each point, found on nearly all modern vid ...
having been designed specifically to be less bulky.
As newer consoles were released into the newly invigorated market, new port designs were introduced for every different model. Meanwhile, the
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...
had introduced the 15-pin
game port
The game port is a device port that was found on IBM PC compatible and other computer systems throughout the 1980s and 1990s. It was the traditional connector for joystick input, and occasionally MIDI devices, until made obsolete by USB in the ...
that was designed primarily for analog inputs, but use remained rare until the introduction of popular
flight simulator
A flight simulator is a device that artificially re-creates aircraft flight and the environment in which it flies, for pilot training, design, or other purposes. It includes replicating the equations that govern how aircraft fly, how they rea ...
s.
By the mid-1990s, the Atari standard was becoming obsolete when home computers like Atari ST and Amiga exited markets along with Sega Genesis game console. With the Atari STE Atari introduced the enhanced joystick port (15 pin dsub) alongside the 2 joystick ports from Atari ST, and when
Atari Jaguar
The Atari Jaguar is a home video game console developed by Atari Corporation and released in North America in November 1993. Part of the fifth generation of video game consoles, it competed with the 16-bit Sega Genesis, the Super NES and the ...
was released, they only used the enhanced joystick port. Nevertheless, it was so popular during its run that it remains a common staple in video game iconography to this day, and is commonly referred to as the symbol of the 1980s video game system and system design. There have also been numerous systems to allow the ports to be adapted to
Universal Serial Bus
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
, and even entirely new Atari-like joystick designs using USB.
Description
The Atari joystick port used a 9-pin male socket in the host system, and female connectors on the devices. Classic Atari peripherals used a teardrop shaped rounded plug that was easy to grip to make it easier to plug in. Almost all compatible devices used similar physical layouts, often to the point of copying the plug design outright.
In the Atari consoles and 8-bit computers, reading the stick inputs was handled by a polling process that set values in various 8-bit registers. In the 8-bit machines, for instance, the pins in the port were connected to custom I/O hardware. The instantaneous values were polled 30 times a second during the
vertical blank interrupt
{{unreferenced, date=February 2008
A vertical blank interrupt (or VBI) is a hardware feature found in some legacy computer systems that generate a video signal. Cathode-ray tube based video display circuits generate vertical blanking and vertical ...
(VBI) when the
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
(OS) handled a number of housekeeping tasks. Depending on settings in other registers, the inputs on the pins were interpreted in a number of ways and then the output data was placed in a number of
RAM
Ram, ram, or RAM may refer to:
Animals
* A male sheep
* Ram cichlid, a freshwater tropical fish
People
* Ram (given name)
* Ram (surname)
* Ram (director) (Ramsubramaniam), an Indian Tamil film director
* RAM (musician) (born 1974), Dutch
* ...
registers. Atari referred to this copying from hardware to the RAM as "shadowing".
Joysticks
![Atari-2600-Joystick](https://upload.wikimedia.org/wikipedia/commons/3/33/Atari-2600-Joystick.jpg)
Atari joysticks included four internal switches to encode direction, and a fifth for the trigger button. Each of these led directly to a pin in the port, and from there to an input on one of the I/O chips. The OS would read these inputs on each VBI, and then copy their status into the shadow registers, with the lower-numbered ports in the least significant bits. For instance, if stick 0 was being pushed up and to the right, the
PORTA
register would have bits 0 and 3 set, or decimal value 9. The status of each of the joystick's trigger buttons was instead placed in four separate registers, whose zero-bit would be set to 1 if the trigger was pushed.
Driving controllers
Driving games of the 1980s were generally top-down and used a unique controller that would cause the car to turn at a fixed rate to one side or the other or go in a straight line (Atari's ''
Night Driver'' is a notable exception). These games were controlled not by a wheel that pointed left or right like in a real car, but a wheel that sent left or right commands only if it was actively spinning in that direction. Players would spin the wheel rapidly to get the car to turn as fast as possible in the desired direction, and then brake the wheel with their hands to go straight again.
Driving controllers were implemented on Atari consoles with a device that worked in the same fashion as the joysticks, pressing each directional switch in turn as it spun. Programs had to watch the sequence of bits in the shadow registers in order to tell if the controller was being spun to the right or left. The OS itself did not attempt to interpret this to provide "right" and "left" instructions for the programmer.
Paddles
![Atari-2600-Paddle-Controller-FR](https://upload.wikimedia.org/wikipedia/commons/7/78/Atari-2600-Paddle-Controller-FR.jpg)
Paddles are analog devices normally used to control horizontal positioning of the player on the screen. On the Atari systems, the paddles were connected in pairs, allowing up to four people to play together on a two-port system.
The paddles worked by connecting the +5 V line through a
potentiometer
A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat.
The measuring instrume ...
(pot) and then back into pins 5 and 9, one for each paddle in the pair. Those pins were connected to a
capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals.
The effect of ...
, slowly charging it at a rate set by the position of the pot. When the voltage in the capacitor reached a threshold value, it caused an interrupt in the OS that copied the value of the ''
color clock'' value from the video hardware. Normally this produced a value from 0 to 228 which was stored as an 8-bit value in the appropriate
POT
shadow register.
One advantage to this system was the color clock values provided by the paddle controllers were the same numbers that controlled the horizontal location of
sprites, meaning that the programmer could simply copy the value of the pot shadow register into the sprite's horizontal position register and it would appear at the appropriate location on-screen.
Keyboard controllers
![Atari-2600-Keyboard-Controller-FL](https://upload.wikimedia.org/wikipedia/commons/5/50/Atari-2600-Keyboard-Controller-FL.jpg)
Keyboard controllers were used in the Atari systems as auxiliary inputs, for numeric keypads on the 8-bit machines and special purpose controllers on the 2600, like the ''
Star Raiders
''Star Raiders'' is a first-person space combat simulator for the Atari 8-bit family of computers. It was written by Doug Neubauer, an Atari employee, and released as a cartridge by Atari in March 1980. The game is considered the platform's kille ...
'' port. They were based on a 4-by-3 matrix for a total of 12 possible keys. For any keypress, the row was encoded by setting one of four bits in the joystick shadow register,
PORTA
or
PORTB
, while the column set a bit on one of the trigger registers. The programmer then had to read both to determine which key was pressed; there was no firmware to map this onto key codes (which the 2600 lacked anyway).
Light pen
![Atari XG-1 light gun](https://upload.wikimedia.org/wikipedia/commons/6/60/Atari_XG-1_light_gun.jpg)
Light pens were directly supported as well. In this case, a
phototransistor
A photodiode is a light-sensitive semiconductor diode. It produces current when it absorbs photons.
The package of a photodiode allows light (or infrared or ultraviolet radiation, or X-rays) to reach the sensitive part of the device. The packa ...
in the light pen was connected to the trigger line of the port. If placed in light pen mode, whenever the trigger was seen to go low, the OS would copy the color clock value into the
PENH
register to record the horizontal position, and the
VCOUNT
register of the video hardware into the
PENV
register. The result was a set of two eight-bit values directly encoding the position of the pen in X and Y using the same coordinates as the video hardware. A sprite can then be set to those coordinates and will appear under the light pen. As the timers were not very accurate, the positions had to be averaged over several screens to produce a usable value.
Graphics tablets
Graphics tablets were handled using the same hardware as the paddle controllers, encoding the X axis as the output of one paddle and the Y axis as the other. There were three buttons, one on the stylus and one on either upper corner of the pad. The stylus button was connected to the up direction of the joystick port, while the left and right buttons on the tablet itself were connected to two of the trigger inputs.
Output
Because the pins of the joystick were wired directly to the input/output controllers on the
motherboard
A motherboard (also called mainboard, main circuit board, mb, mboard, backplane board, base board, system board, logic board (only in Apple computers) or mobo) is the main printed circuit board (PCB) in general-purpose computers and other expand ...
, it was possible to program them to output to the port, rather than input. This capability was used in the
Atari XEP80 80-column card, which used pin 1 as an output pin, and pin 2 as an input. A
device driver
In computing, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabling operating systems and ot ...
used these pins to implement a bidirectional
serial port
In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. ...
, which worked in joystick port 1 or 2. Similar drivers were used by other devices, like modems, which avoided the need to use the more expensive
Atari SIO
The Serial Input/Output system, universally known as SIO, was a proprietary peripheral bus and related software protocol stacks used on the Atari 8-bit family to provide most input/output duties for those computers. Unlike most I/O systems of the ...
system.
Other platforms
Fully compatible systems
The
VIC-20
The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit home computer that was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore's first personal computer, the PE ...
has one ''Control Port'', and the
Commodore 64
The Commodore 64, also known as the C64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in the Guinness ...
had two ports, each a complete implementation of the Atari standard. They differed from the Atari systems primarily in the hardware used to decode the inputs.
The digital pins on the Commodore 64's control ports were read by a
MOS Technology CIA
The 6526/8520 Complex Interface Adapter (CIA) was an integrated circuit made by MOS Technology. It served as an I/O port controller for the 6502 family of microprocessors, providing for parallel and serial I/O capabilities as well as timers ...
chip, and the analog paddle inputs in fashion similar to the Atari by the
MOS Technology SID
The MOS Technology 6581/8580 SID (Sound Interface Device) is the built-in programmable sound generator chip of Commodore's CBM-II, Commodore 64, Commodore 128 and Commodore MAX Machine home computers. It was one of the first sound chips of it ...
sound chip in conjunction with a timer.
There was only one set of two inputs for this purpose in the SID, so another register controlled which of the two ports was connected to the SID at any given instant. Light pens could only be used in Control Port 1 and worked in a similar way to the Atari, but was based on a faster clock so the horizontal axis read from 0 to 511. The accuracy was the same as the Atari however, as the values were rounded off to even values only.
The same port pins on the CIA #1 were was also used for handling the keyboard and other housekeeping tasks, which led to some problems. For instance, the left direction switch of Control Port 1 was wired to the same input as the key on the keyboard, and when it was used it would cause scrolling in BASIC programs to slow down. Due to the way keyboard scanning was handled, holding down the trigger would cause random characters to be generated. As a result, many C64 games required the joystick to be plugged into Control Port 2.
On the
Atari ST
The Atari ST is a line of personal computers from Atari Corporation and the successor to the Atari 8-bit family. The initial model, the Atari 520ST, had limited release in April–June 1985 and was widely available in July. It was the first pers ...
, the two ports were normally configured with Port 0 set to mouse mode and Port 1 to joystick. In joystick mode they operated largely identically to the earlier machines, but in mouse mode the system watched the ports for discrete inputs on the various directional pins, or "events". The mouse sensor generated 200 events for every inch of movement, and the system could track these fast enough to handle movements of up to 10 inches per second. Handling the ports, the keyboard and a
real-time clock
A real-time clock (RTC) is an electronic device (most often in the form of an integrated circuit) that measures the passage of time.
Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are pr ...
was a dedicated Intelligent Keyboard (ikbd) controller. The ST implementation of the joystick port lacked analog input, the following STE model introduced an enhanced joystick port which used a 15-pin dsub that had analog support.
The Commodore
Amiga
Amiga is a family of personal computers introduced by Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly improved graphi ...
had a complete two-port implementation known as ''gameport''s. Unlike earlier systems that had to be interpreted by examining bits in registers, the Amiga's OS had a number of drivers and libraries that made interaction simple. This included handlers for five types of input devices, include mice, joysticks, light pens and "proportional controllers" as a catch-all for analog inputs like paddles and analog joysticks. They also had settings for how and when the OS would report changes. For instance, the programmer could set the drivers to only report when the mouse had moved at least 10 events, thus lowering how often they had to deal with mouse movement.
Semi-compatible systems
The
TI-99/4A
The TI-99/4 and TI-99/4A are home computers released by Texas Instruments in 1979 and 1981, respectively. Based on the Texas Instruments TMS9900 microprocessor originally used in minicomputers, the TI-99/4 was the first 16-bit home computer. ...
home computer series used a 9-pin connector that was physically identical to the Atari version, as well as being similar in terms of the devices and the way they worked. However, the port's pins were re-arranged and it used the separate grounds to select which joystick to read, so it was not directly compatible. Converters allowing Atari-standard devices to be plugged in were both simple and very common. The manufacturer and most makers of adapters included diodes on all lines of each joystick except the grounds to prevent false key presses.
The
ColecoVision
ColecoVision is a second-generation home video-game console developed by Coleco and launched in North America in August 1982. It was released a year later in Europe by CBS Electronics as the CBS ColecoVision.
The console offered a closer expe ...
game console extended the 2600 controller with two (or four) triggers and a 12 key pad. The ColecoVision also supported driving controllers and
trackball
A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down ball mouse with an exposed protruding ball. Users roll the ball to position the on-s ...
s. Many ColecoVision games can be played with an Atari-compatible controller, if a Coleco controller is plugged into the second port and used to select the game.
The
Atari 7800
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 one o ...
game console extended the 2600 controller with a second trigger. 7800 games not requiring two triggers can be played with classic controllers.
MSX home computers used a slightly modified version of the port, replacing one of the analog inputs with a second trigger, and the other with a ''strobe'' pin. Under normal operation, any Atari style joystick could be used, although it would lack the second trigger button. The strobe pin was used to support mouse input. Electrically, a mouse generates what is essentially a random stream of pulses as it moves. On systems like the ST and Amiga, custom hardware was used to carefully track these in order for the motion to be smoothly followed, as the
CPU might become too busy with other tasks to follow the rapid interrupts. Less powerful 8-bit designs did not have the performance to smoothly track a mouse without additional hardware, and the MSX designs, based on off-the-shelf hardware, lacked this ability. Instead, the tracking hardware was moved into the mouse. The mice held two 8-bit values tracking the movement in X and Y since the last time they had been polled. To read the values out, the strobe pin was pulled high four times. With each pulse, a
nibble
In computing, a nibble (occasionally nybble, nyble, or nybl to match the spelling of byte) is a four-bit aggregation, or half an octet. It is also known as half-byte or tetrade. In a networking or telecommunication context, the nibble is oft ...
of the two bytes was output on the four directional pins in serial fashion. The strobe pulse also reset the value to zero, starting the polling process over again. MSX mice were expensive, and this led to adaptors for PS/2 style mice, which operated along similar principles.
Sega Master System
The is an 8-bit
third-generation home video game console manufactured by Sega. It was originally a remodeled export version of the Sega Mark III, the third iteration of the SG-1000 series of consoles, which was released in Japan in 1985 and ...
and
Sega Genesis
The Sega Genesis, known as the outside North America, is a 16-bit Fourth generation of video game consoles, fourth generation home video game console developed and sold by Sega. It was Sega's third console and the successor to the Master Syst ...
game console controllers are backwards-compatible and can be used with the Atari 2600.
Not all
Magnavox Odyssey 2
The Magnavox Odyssey 2 (stylized as Magnavox Odyssey²), also known as Philips Odyssey 2, is a second generation home video game console that was released in 1978. It was sold in Europe as the Philips Videopac G7000, in Brazil and Peru as the P ...
systems had removable controllers. For the models that do, a simple adapter to rearrange the pins is all that is required.
Some
Amstrad PCs, that were otherwise
IBM PC compatible
IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC clones. ...
, had Atari-compatible digital gameports rather than the
PC analog standard. Software such as ''
Elite
In political and sociological theory, the elite (french: élite, from la, eligere, to select or to sort out) are a small group of powerful people who hold a disproportionate amount of wealth, privilege, political power, or skill in a group. D ...
'' and
GEM
A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, a ...
had support for the Amstrad digital gameport. Otherwise, the joystick directionals were mapped to keys on the keyboard.
Systems using adaptors
The Apple II also had a joystick port using a 9-pin D-sub, but it was a very different system that connected two analog joysticks to a single port. These were not very suitable for directional games, and adapters for Atari port devices were common, both commercial ones like the
Sirius Joyport, as well as many home-brew systems. Unlike the ports used on the Commodore systems, most of the homebrew systems only adapted the joystick, and generally did not include the other inputs. These adapters did not allow the analog inputs of paddles to be used, in spite of the port already handling these inputs directly meaning all that was needed was a mechanical adapter.
The
Sinclair ZX Spectrum
The ZX Spectrum () is an 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer.
Referred to during development as the ''ZX81 Colour ...
prior to the Spectrum +2 had no built-in controller port, which led to a profusion of different inputs. Atari port adapters were common, and several devices emerged including the
Kempston Interface
Kempston Micro Electronics was an electronics company based in Kempston, Bedfordshire, England specialising in computer joysticks and related home computer peripherals during the 1980s.
The Kempston Interface, a peripheral which allowed a joys ...
and
ZX Interface 2 that were incompatible with each other. The Interface 2 turned joystick presses into keyboard presses, and thus could not generate the analog signals of the paddles. The later Amstrad-built Spectrum models - the +2, +2A, and +3 - included two built-in joystick ports, however the pinout of the connectors was non-standard. One-button Atari joysticks can be used with a simple wiring adaptor to convert the ports to the standard pinout.
The
BBC Micro
The British Broadcasting Corporation Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by Acorn Computers in the 1980s for the BBC Computer Literacy Project. Designed with an emphas ...
had a relatively complex port system which was based on a 15-pin D-connector that supported two analog joysticks like the ones on the Apple II. These ran to dedicated analog-to-digital circuitry, which made them excellent for the sort of interfacing tasks seen in (for instance)
AtariLab. However, the popularity of the Atari port was such that adapters were also available for this system, varying widely in the number and types of control devices they supported.
Chart of compatible systems
(*1) Atari 7800 buttons require special wiring.
(*2) For the second button/right mouse button the POT X line is used (and for 3rd button/middle mouse button POT Y) which, different to the other lines, must be pulled to VCC via the button.
(*3) The CD32 supports "game pad mode" and uses pin 5 to switch to it; it is pulled to active high by the CD32. Actual CD32 controllers have active components. Regular "Atari" joysticks will work at the CD32, but CD32 controllers will not work with e.g. a C-64.
(*4) The "Sega" controllers cannot be converted into "Atari" joysticks simply by rewiring them. Unlike regular "Atari" joysticks, they contain pull-up resistors for each signal line (which might interfere with scanning the keyboard on C64) and some controllers may contain active circuits and will not work without the VCC. The Mega Drive controllers use an active circuit.
(*5) The respective GND lines are pulled low to select the respective "row". Regular joysticks use row 9.
(*6) Refers to the ports built into the ZX Spectrum +2, +2A, and +3 models. Other Spectrum joystick interfaces typically match the 1-button "Atari" pinout.
(*7) The TI-99/4A and Tutor/Pyuuta controllers were typically two controllers plugged into one port. The pinouts need 1N914 diodes with the Cathode pointed to the controller side to prevent false key presses.
Notes
References
Citations
Bibliography
*
*
*
* {{cite book , title=Commodore 64 Programmers Reference Guide , url=http://www.commodore.ca/manuals/c64_programmers_reference/c64-programmers_reference.htm , date=1982 , publisher=Commodore Business Machines , ref=CITEREFCommodore1982
Atari hardware
Computer connectors
Legacy hardware
Game controllers