debian-hppa on a C8000

Hi,

the "native" OS of the old HP workstations is HP-UX, but just out of 
curiosity I've tried to install Linux on one of my C8000. Installing 
using a CD with debian-8.0-hppa-CD-1.iso as described in the Linux 
PARISC Wiki succeeded without problems, but I couldn't install any 
updates. During the installation, the installer asks for the radeon 
firmware R300_cp.bin, but I continued the installation without it. 
Installing /lib/firmware/radeon/R300_cp.bin afterwards breaks the 
system, it crashes during booting. This is also the case after an 
"apt-get update;apt-get upgrade". I've then tried to install 
debian-9.0-Stretch-hppa-NETINST-1.iso and 
debian-10.0-hppa-NETINST-1.iso, but here the installer crashes already 
shortly after entering the locale information.

Did anybody succeed in installing a more recent version than debian-8.0?