The whole story is in the forum :

https://www.linuxquestions.org/quest...ed-4175562338/

I am giving you a shortened version, just to celebrate. And because I did not have a place to do so, when " I " solved some other problems, quite magically, after someone from the family had taken a quick look, or my other friend had shaken his head about my decisions ...

It is just this:
I had been unable to run XOrg with reasonable resolution on a very old desktop-computer (flat computer case, monitor on top). I identify the problem with the ATI-rage card and some driver incompatibility which would not let me choose the right VESA-mode nor run the card with different drivers.
The computer had been handed to me by a friend who hoped to replace an illegally installed Windows XP by any kind of Linux. As she had bought the machine second-hand and the task asked too much of her, she thought I were more experienced and could quickly present her a nicely running machine.

As my struggle continued, I gave an account to one of my wife's retired uncles who has never had any reason to assemble computers or to configure operating systems. He listened and asked in the very end: "What is a graphics card ?"

A few days later he told me about another old and defective machine, that he has kept for no special reason in his cellar. Then : "Would that help?" and he handed me the card that he has extracted from the wreck... An old NVidia GeForce FX chip on a no-name card... It gave me the shivers, first, but nothing bad happened, when I tried it in the other computer. I just had to unscrew the metal plate (whatever is the right name for it) from the card, because the desktop case is narrower than later PC-towers.

But the darned thing is running now and the screen is happily fed with the right resolution, too !

Drum roll and fanfare! Now! Really!