There are still many users of touchpad and clickpad calcs out there, stuck on OS 3.9.0.
This is unfortunate for users of Touchpad CAS calcs, as there is no working Ndless for it.
Additionally, even on Clickpad (CAS/non-CAS) and Touchpad non-CAS, a USB cable and host device were required for the installation, which is rather inconvenient.
Now a separate ndless_installer_3.9.0_classic_new.tns based on the ideas for Ndless 4.4 is now available for all users of 3.9.0 on classic calcs!
The installer is part of the latest ndless download!