The first model of the Nintendo Entertainment System (NES) has a 10NES lockout chip to prevent unauthorized games from being played which many of the companies worked around. The negative result to the consumer is that this chip caused reliability issues with the system resulting in blank screens. If the chip is disabled manually or by the use of a 3rd party device (blinking light win) then it is much more reliable.

The top loader model of the NES later released removed this chip making it more reliable in that respect. My question is, would disabling or using the BLW violate the DMCA or any other US law?



4 Answers 4


The function of the 10NES / CIC Chip

The CIC chip was used first at the SNES, and was the base for most authentication. It ran proprietary software that would be seeded with random numbers, and it aborts the game in case that some calculations did come to a bad result.

Bypassing it was done with one of three methods:

  • modifying the console and disabling the chip, which is legal.
  • use a specialized chip that...
    • answers to the CIC with the authentic answers.
    • just freezes the CIC chip by giving it a Zap.

Faking Authentification

There's basically two ways to fake authentication: either you use a copy of the actual chip's proprietary code, or mimicking the proper output. And here the legal trouble starts:

Wholesale copying the code or even the significant portions is copyright infringement and illegal.

Tricking the US copyright office to get a hold of the trade secret copyrighted code, like Atari did? Highly illegal. Copying portions of that illegally obtained code? Copyright infringement and illegal, and the court even denied Atari many defenses because they had fooled the copyright office to get the code. You can read the verdict here, but I want to quote this paragraph (emphasis mine):

In this case, the source code obtained from the Copyright Office facilitated Atari's intermediate copying of the 10NES program. To invoke the fair use exception, an individual must possess an authorized copy of a literary work. See Harper & Row, 471 U.S. at 562-63, 105 S.Ct. at 2232 (Knowing exploitation of purloined manuscript not compatible with "good faith" and "fair dealings" underpinnings of fair use doctrine.). Because Atari was not in authorized possession of the Copyright Office copy of 10NES, any copying or derivative copying of 10NES source code from the Copyright Office does not qualify as a fair use.

But reconstructing a workaround chip? That actually is legal, as the very case determined in the very next paragraph:

Reverse engineering, untainted by the purloined copy of the 10NES program and necessary to understand 10NES, is a fair use. [Explanation of the process used before Atari resorted to tricking the Copyright office] This "reverse engineering" process, to the extent untainted by the 10NES copy purloined from the Copyright Office, qualified as a fair use.

And deconstructing the chip to show the results? That's actually legal. Even the court in the Atari-case said so, and had Atari succeeded in their tries, they would have not had to result to illegal methods to get a hold of the code.

Zapping the chip

While Atari's "Rabbit" chip was ill-gotten gains, other companies made different legal workarounds: Interrupt the function of the chip by shocking the CIC? That's legal.

GameBoy Authentification

The GameBoy used a variant system. It did not rely on code secrecy but worked with the Trademark - offering a different venue to strike at infringers. The GB BootROM relied on loading and then checking if the game was offering the Nintendo logo. If the logo wasn't readable, it would not boot. To make a game run, the most simple way would be to include the Nintendo Logo. There is a more complex solution that first displays the maker's logo and then offers the Nintendo Logo for verification in the second step.

The simple solution: just display Nintendo-TM

If the game simply offered the official, registered Nindendo logo, it would offer to be endorsed or made by Nintendo. This would be a violation of the Nintendo trademarks, and illegal.

Tricking the chip

By displaying the own logo on the step 1 but offering the Nintendo-TM Logo in the 2nd step, the solution is very akin to the Lexmark Cases. As the courts in the 2004 case held, it is allowable to bypass an authentication chip. You are also allowed to reverse engineer code to trick it. But you are not allowed to just copy the Nintendo code "10NES" on the CIC chip.


Considering this appears to be a sort of dongle for an outdated system, chances are that it would fall under a 2010 DMCA exemption. (As described by DMCA section 1201).

  • And it is no DMCA violation without at least attempting to make illegal copies of something. I don’t see anyone attempting to infringe on Nintendo’s copyright. I think Lexmark ran into that problem when they tried to use the DMCA to prevent people from using third party ink in their printers.
    – gnasher729
    Apr 2, 2021 at 13:29
  • 1
    the Lexmark cases
    – Trish
    Jul 30, 2021 at 11:14

This could violate the DMCA.

A dongle is a removable hardware component that is necessary for software to run. The 10NES chip is a permanent component that blocks software from running.

Disabling the 10NES chip is not a dongle bypass. It is a form of jailbreaking. You are allowing unauthorized software to run on the system.

As noted in this article, the jailbreaking exemption does not apply to video game systems.

The Lexmark case may or may not be applicable here. One difference is that that case referred to a device that bypasses the authentication process. This is analogous to making a game that can fool the 10NES chip (like Tengen did). What you are talking about sounds like you are disabling the authentication process altogether. It's hard to say for sure since I don't know anything about the BLW program, and the link in the question is no longer functional.

Another relevant case might be SCEA v. Hotz, where Sony sued someone for jailbreaking the PS3. This case was settled out of court, but Sony was awarded an injunction against Hotz.

  • Does the chip control access to any copyrighted work?
    – Someone
    Sep 24, 2022 at 15:30

Not a covered DMCA exemption

This sounds like it would run afoul of this,

(A)No person shall circumvent a technological measure that effectively controls access to a work protected under this title. The prohibition contained in the preceding sentence shall take effect at the end of the 2-year period beginning on the date of the enactment of this chapter.

But on further reading there is an exemption,

(B)The prohibition contained in subparagraph (A) shall not apply to persons who are users of a copyrighted work which is in a particular class of works, if such persons are, or are likely to be in the succeeding 3-year period, adversely affected by virtue of such prohibition in their ability to make noninfringing uses of that particular class of works under this title, as determined under subparagraph (C).

Subparagraph C defines who gets to determine a "noninfringing use",

(C) ... Librarian of Congress, upon the recommendation of the Register of Copyrights, who shall consult with the Assistant Secretary for Communications and Information of the Department of Commerce and report and comment on his or her views in making such recommendation, shall make the determination in a rulemaking proceeding for purposes of subparagraph (B) ...

The exceptions to the DMCA are determined by Librarian of Congress. The Librarian of Congress's latest recommendation can be found in "Federal Register / Vol. 86, No. 206 / Thursday, October 28, 2021 / Rules and Regulations 59627 ". In it, it explicitly says,

(14) Computer programs that are contained in and control the functioning of a lawfully acquired device that is primarily designed for use by consumers, when circumvention is a necessary step to allow the diagnosis, maintenance, or repair of such a device, and is not accomplished for the purpose of gaining access to other copyrighted works. For purposes of this paragraph (b)(14):

  • (i) The ‘‘maintenance’’ of a device is the servicing of the device in order to make it work in accordance with its original specifications and any changes to those specifications authorized for that device; and
  • (ii) The ‘‘repair’’ of a device is the restoring of the device to the state of working in accordance with its original specifications and any changes to those specifications authorized for that device. For video game consoles, ‘‘repair’’ is limited to repair or replacement of a console’s optical drive and requires restoring any technological protection measures that were circumvented or disabled.

So basically you can only circumvent the copy protection to replace the optical drive, and it must work after the repair.

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