What is the point of the "license" on the TI-OS download pages? You don't need permission to use it. Copyright law (at least in the US) already allows end-users to install and use software without permission from the copyright owner. The "license" doesn't actually give you anything or allow you to do anything that you didn't already have the right to do in return. You can already legally download a copy from TI's site and install and use it in your emulator as you wish, or download it and install it on your real calculator.
There's simply no need to agree to the terms and conditions of the "license" to download and use a TI-OS file (and downloading a file from the download page does not indicate agreement, despite what TI might claim).
Edit to add: if you dump the ROM from your calculator, you are also not subject to any "license". You did not have to agree to any license when you purchased the calculator, and some license on TI's site does not apply to your use of your own calculator.
Edit to add again:
@Keoni there's a EULA in the packaging which you agree to by using the calculator.
The TI-OS EULA (like virtually every other EULA) is a contract, and you are bound to the terms and conditions of that contract
only if you indicate assent, and simply using the calculator does not indicate your assent to a contract that is packaged alongside the calculator.
When you bought the calculator, you own the copy of software on it*, and you have full rights to use the software without accepting any contract. Under copyright law, TI has the exclusive right to copy and distribute the software but not to
use the software. Use of software (or book, CD, DVD, etc) is not even covered by
copyright law (after all, it's not a
useright law), except when copying is required to make use of a copyrighted work, as it is with software (but as I mentioned, this right is explicitly granted by copyright law to the owner of a copy of software).
*A lot of trolls in the software industry would claim that you only "licensed" the software and didn't buy it, but they are mistaken from a legal standpoint.