10NES
Encyclopedia
Nintendo Entertainment System
The Nintendo Entertainment System is an 8-bit video game console that was released by Nintendo in North America during 1985, in Europe during 1986 and Australia in 1987...
(NES) video game console
Video game console
A video game console is an interactive entertainment computer or customized computer system that produces a video display signal which can be used with a display device to display a video game...
. Various companies found ways to bypass the authorization chip.
Design
The system consisted of two parts, a microchipIntegrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
in the NES that would check the cartridge in the system for authentication, and a microchip in the cartridge that would give the 10NES code upon demand. If the cartridge did not provide the authentication, then the 10NES would reset the CPU during every cycle until a game with the authorization chip was inserted. The constant resetting of the CPU would stop the NES from booting up. However in some instances, the 10NES has been prone to reset the CPU if it fails to authenticate a legal cartridge. The 10NES was patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
ed under and the source code was copyrighted; only Nintendo
Nintendo
is a multinational corporation located in Kyoto, Japan. Founded on September 23, 1889 by Fusajiro Yamauchi, it produced handmade hanafuda cards. By 1963, the company had tried several small niche businesses, such as a cab company and a love hotel....
could produce the authorization chips. The patent covering the 10NES expired on January 24, 2006, although the copyright is still in effect.
The 10NES chip was only installed in the model NES-001 Control Deck, not the model NES-101.
Circumvention
Most unlicensed companies created circuits that used a voltage spikeVoltage spike
In electrical engineering, spikes are fast, short duration electrical transients in voltage , current , or transferred energy in an electrical circuit....
to knock the authentication unit in the NES offline.
A few unlicensed games released in Europe and Australia (such as HES
Home Entertainment Suppliers
Home Entertainment Suppliers Pty. Ltd. is an Australian company that distributes computer games and gaming equipment. HES offices are based in Riverwood, Sydney....
games) came in the form of a dongle
Dongle
A software protection dongle is a small piece of hardware that plugs into an electrical connector on a computer and serves as an electronic "key" for a piece of software; the program will only run when the dongle is plugged in...
that would be connected to a licensed cartridge, in order to use that cartridge's 10NES lockout chip for authentication.
Tengen
Tengen (company)
Tengen was a video game publisher and developer that was created by arcade game manufacturer Atari Games.-History:Atari had been split into two distinct companies. Atari Corporation was responsible for computer and console games and hardware and owned the rights to the Atari brand for these domains...
(Atari
Atari
Atari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...
’s NES games subsidiary) took a different tactic: the corporation obtained a description of the code in the lockout chip from the United States Patent and Trademark Office
United States Patent and Trademark Office
The United States Patent and Trademark Office is an agency in the United States Department of Commerce that issues patents to inventors and businesses for their inventions, and trademark registration for product and intellectual property identification.The USPTO is based in Alexandria, Virginia,...
by claiming that it was required to defend against present infringement claims in a legal case. Tengen then used these documents to design their Rabbit chip, which duplicated the function of the 10NES. Nintendo sued Tengen for these actions. The court found that Tengen did not violate the copyright for copying the portion of code necessary to defeat the protection with current NES consoles, but did violate the copyright for copying portions of the code not being used in the communication between the chip and console. Tengen had copied this code in its entirety because future console releases could have been engineered to pick up the discrepancy. On the initial claim, the court sided with Nintendo on the issue of patent infringement, but noted that Nintendo’s patent would likely be deemed obvious as it was basically with the addition of a reset pin, which was at the time already commonplace in the world of electronics. Therefore, while Nintendo was the winner of the initial trial, before they could actually enforce the ruling they would need to have the patent hold up under scrutiny, as well as address Tengen’s antitrust claims. Before this occurred, the sides settled.
A small company called RetroZone, the first company to publish games on the NES in over a decade, uses a multi-region lockout chip for NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...
, PAL A, and PAL B called the Ciclone which was created by reverse engineering Tengen
Tengen (company)
Tengen was a video game publisher and developer that was created by arcade game manufacturer Atari Games.-History:Atari had been split into two distinct companies. Atari Corporation was responsible for computer and console games and hardware and owned the rights to the Atari brand for these domains...
's "Rabbit" chip. It is the only lockout chip in existence that will allow games to be played in more than one region. It is intended to make the games playable on the original NES-001 hardware that uses the 10NES lockout chip and the two other regions - the other region free alternative would be the top-loading NES, which does not feature the lockout chip. The Ciclone chip is the first lockout chip to be developed after the patent for the 10NES had expired.
Because the 10NES in the model NES-001 Control Deck occasionally fails to authenticate legal cartridges, a common modification is to disable the chip entirely by cutting pin 4 on the Control Deck's internal 10NES lockout chip.