Another six month have passed, so my good old laptop from pre-2000 got another update. I updated the already running fedora 18 to fedora 19 by using the fedUp tool.
The update took longer than on more recent systems (of course) but it worked flawlessly.
After that I booted into the LXDE desktop of Fedora 19. Everything worked as before. The machine is still too slow for most uages, even webbrowsing is painful. Work with libreOffice is probably doable.
Still, one big downside of modern linux distributions is that there is no video acceleration for this old graphic chipset anymore. So most videos can not be played. On the positive side, I was surprised to find that suspend to ram and suspend to disk both worked flawlessly on Fedora 19. Good work to remain compatible with APM (pre-ACPI)!