EpicFail v1.0
08/29/2011
Brandon Wilson

>what is it?
This is an assembly program for the TI-84 Plus, TI-84 Plus Silver Edition, and TI-84 Pocket.fr which patches the boot code to eliminate the unnecessary 2048-bit RSA validation for newly-received operating system upgrades.

TI felt it necessary to waste 5 minutes of their users' time trying to stop something of no threat to them and which was easily broken before the new validation even made it to the general public.

We can play it this way if you want, TI.

>What are the risks to using this?
This program MODIFIES the NORMALLY-PROTECTED BOOT SECTOR OF YOUR CALCULATOR to remove the 2048-bit RSA signature check TI added after the 512-bit RSA key factorings. This check is completely unnecessary and takes over 5 minutes of time to complete; this is a waste of everyone's time and you shouldn't have to put up with it. The 512-bit RSA validation check is still in place, so removing this check doesn't increase instability of your calculator, the potential for a bad Flash, or anything remotely like that.

However:

PLEASE BE AWARE THAT WHILE EXTREMELY UNLIKELY, SIMPLY RUNNING THIS PRORGAM CAN POTENTIALLY DAMAGE YOUR CALCULATOR PERMANENTLY AND PHYSICALLY BEYOND REPAIR BY ANYONE.

I do my best to ensure that nothing goes wrong during the patching process, but nothing is perfect.

DO NOT RUN THIS PROGRAM WITHOUT BEING AWARE OF THE RISKS. I AM NOT RESPONSIBLE FOR ANYTHING THAT HAPPENS TO YOU OR YOUR CALCULATOR BY CHOOSING TO RUN THIS PROGRAM.

I personally ran it on two TI-84 Pluses, two TI-84 Plus Silver Editions, and one TI-84 Pocket.fr without issue.

>How do I use it?
Just run it like any other nostub z80 assembly program: from the homescreen, go to the catalog with [2nd]+[CATALOG], select "Asm(" to paste it to the homescreen, press [PRGM] and select EPICFAIL, and press [ENTER] once you see the following on the homescreen:

	Asm(prgmEPICFAIL

It will verify the patch can be installed and ask you to confirm. Press [ALPHA]+[Y] to continue, or [ALPHA]+[N] to abort.

>How do I undo this patch?
Undoing the patch means erasing and reflashing the boot sector, which is beyond the scope of this program. To undo this patch, you can obtain a stock boot code 1.03 Flashy AppVar (it contains copyrighted TI code, so I can't tell you where to get it; look around) and use Flashy to flash it to your calculator.

In all honesty, though, I don't see a need to ever remove it.

>Version History
v1.0 - initial release.