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EFF: TI calculator hackers didn't violate DMCA

Texas Instruments wrongly demanded that enthusiasts remove posts about digital keys used to put a new OS on their calculators, the foundation argues.

The Electronic Frontier Foundation on Tuesday rebutted legal assertions by Texas Instruments that enthusiasts who figured how to install their own operating systems on TI calculators violated the Digital Millenium Copyright Act.

In a letter sent to the processor and calculator maker, Jennifer Granick, civil-liberties director at the EFF, argued that TI calculator enthusiasts Brandon Wilson, Tom Cross, and Duncan Smith didn't deserve letters TI sent them August 27 demanding that they remove various online posts about installing alternative operating systems. The three had taken down the posts but plan to restore them October 26, unless TI supplies evidence of a violation, Granick said.

The TI-83 Plus calculator
The TI-83 Plus calculator Texas Instruments

In the posts, the three discussed use of reverse-engineered digital keys that made it simple to install alternative operating systems on the TI calculators. Wilson and Smith posted the actual keys that could be used to perform the installation.

But none of that violated the DMCA's anticircumvention provision, which states, "No person shall circumvent a technological measure that effectively controls access to a work" protected under the copyright act, Granick said.

For one thing, the calculators' operating systems already were available in unencrypted form on the calculator itself, easily retrieved by connecting it with a computer. For another, TI made the operating systems available for download on its Web site, she said.

"The key Texas Instruments is so concerned about doesn't have anything to do with protecting the operating systems in any way," Granick said.

In a statement, Cross added, "The DMCA should not be abused to censor online discussion by people who are behaving perfectly legally. It's legal to engage in reverse engineering, and its legal to talk about reverse engineering."

TI didn't immediately respond to requests for comment.

So was it a matter of modifying the copyrighted operating systems themselves?

Section 117 of the Copyright Act also "allows people to modify copies of software they own to make them work better with the devices they own," she added, but in any event, that's not what TI accused the three of doing in the first place, Granick said. There are several alternative operating systems available at, a site that has been documenting TI calculator technology since 1996 and that helped publicize the operating-system digital signing key in July.

"With this achievement, any operating system can be cryptographically signed in a manner identical to that of the original TI-OS. Third-party operating systems can thus be loaded on any 83+ (TI-83 Plus) calculators without the use of any extra software," Michael Vincent, the site's news editor, said in announcing the keys in July. "Complete programming freedom has finally been achieved on the TI-83 Plus!"

The trio were not alone in receiving DMCA letters from TI. United TI also received one, and EFF said TI sent a "torrent" of them.