Solution 12151: Updating to Operating System (OS) Version 3.10 for the TI-89 Titanium and Voyage™ 200 Deletes All Calculator Software Applications (Apps).
Why did all the apps on my calculator disappear when I updated to OS v3.10 on the TI-89 Titanium or Voyage 200?
The TI-89 Titanium and Voyage 200 OS v3.10 will reset the RAM and Flash ROM memory as part of the updating process. This is done to ensure maximum compatibility with the operating system and apps. It is highly recommended that existing programs and apps are backed up before upgrading to OS v3.10
The TI Connect™ software can be used to backup the contents of the calculator before upgrading. For help with performing a backup using TI Connect, refer to Knowledge Base Solution 11181: Creating a Backup of the Files on a Graphing Calculator Using TI Connect.
If the apps were accidently deleted before performing a backup via TI Connect, refer to Knowledge Base Solution 12154: Reloading Calculator Software Applications (Apps) on the TI-89 Family, TI-92 Plus or Voyage™ 200 Graphing Calculator.