I had attend 120th Tokyo area Debian seminar at Shinjuku.
An attendee brought hp Jornada 780 and tried to install Debian, so I helped him.
Using a kernel, boot loader and userland from “Lenny on j720” page and it worked fine, except PCMCIA NIC.
His NIC is Corga PCC-TD is not listed in /etc/pcmcia/*. I didn’t have enough time to write it, so I couldn’t check it.
However, later releases after Lenny don’t have “arm” architecuture, so it should be hard to upgrade it. I don’t know recent Linux kernel work on Jornada 780. The configuration and code for jonrnada 780 are still in the kernel, but it wouldn’t be tested anyone.