Summer 2009, the TI community factored all 512-bits RSA keys used to validate OS and Apps installation on TI-z80 and TI-68k Flash calculators.
This opened the way to:
- patched OSes and Apps
- 3rd party OSes and Apps
Some of the patches disabled the TI-84 PTT mode, and TI must have been bothered with that.
Spring 2011, we discovered a new 1.03 Boot Code on the new TI-84 Pocket and on TI-84 Plus hardware revision Q and above.
That new Boot Code adds a 2nd validation check for the OS installation with a 2048-bits RSA key only included in OS 2.55MP.
So you had to:
- wait 6 additional minutes at the "Validating..." screen after sending an OS
- stay with the lastest 2.55MP OS which breaks compatibility with several asm games
Then, Brandon Wilson discovered a way to reflash the TI-84 Boot Code. You could then downgrade your Boot Code to 1.02 or 1.00 and then downgrade the OS.
But you had to get such Boot Code image, which is different between basic and Silver Edition TI-84.
Brandon then released EpicFail, a Boot Code 1.03 patch. No need to dump the Boot Code on a model you don't own anymore.
But you might break your TI-84 permanently if anything bad happends during the Boot Code flashing, and using such tools might void your warranty from TI point of view.
Brandon then worked on a 3rd way: a patched TI-84 2.43 OS which can be installed on Boot Code 1.03 because of some exploits. But it could not be shared publicly because of copyright reasons...
On TI-Planet we just converted that into a dynamic patch for every TI-84 OS; Make103!
You can now make every TI-84 0.46 to 2.53MP OS installable on your original Boot Code 1.03!
It also works with TI-83 Plus OSes patched to be installed on the TI-84.
For now it doesn't work with 3rd-party OSes which are much smaller and don't reach the 2048-bits RSA key location
(and so exploit) in ROM.
Download from the TI-Planet news:
http://tiplanet.org/forum/viewtopic.php?t=9333
