Search for “BlackBerry 9800 Autoloader” on the Internet Archive. Several users have uploaded disk images containing OS 6 autoloaders. These are slower downloads but safe.
: A vital resource for downloading older .exe loaders and software drivers no longer available on official sites. How to Install the BlackBerry 9800 Autoloader blackberry 9800 autoloader link
While an autoloader is a powerful tool, it comes with important caveats: Search for “BlackBerry 9800 Autoloader” on the Internet
The software is specific to the carrier the phone was originally locked to (e.g., AT&T, Rogers, Vodafone). blackberry 9800 autoloader link