Official downloads from BlackBerry are largely discontinued, but you can find archives on reputable community sites: Internet Archive : Hosts various BlackBerry 10 Autoloaders CrackBerry Forums
If you get device not found , ensure you have installed the BlackBerry 10 SDK (Momentics IDE) – specifically the USB debug driver for the Z3. blackberry z3 stj1001 autoloader developer
Best for a quick file description or "ReadMe" text file included in a ZIP. you now need to:
Once the Autoloader finishes, your STJ1001 is a blank factory device . As a developer, you now need to: blackberry z3 stj1001 autoloader developer