...with MorphOS 3.18 my second monitor did not work any more. So I used the Monitor driver from 3.17 instead and it worked again. I then could adjust the resolution for the secondary monitor in prefs again.
See here : https://morph.zone/modules/newbb_plus/viewtopic.php?topic_id=13557&forum=3#156127
It might change in the future but for now the modes of the secondary display are autogenerated and can't be modified.
@Trekman: It has been reported that there is some regression with PowerMac7,x machines and secondary display support on Radeon96x0 cards, so this might be what you were running into with 3.18.
Is multi monitor supported with a Radeon X1900 GT in a PowerMac 11,2?
I am asking because I only see a mirrored image of the first monitor and I only have a RadeonX1900GT in my mode list in screens preferences, no RadeonX1900GT.1 which should be there, as far as I understand.
I have one port of the gfx card connected with a hdmi adapter to the hdmi input of the monitor and the other port to the dvi input of the same monitor. The screens on both inputs are the same.
Here I still have same mirrored modus only with two monitors. No extra .1 monitor in the modus section of screen prefs!? Am I doing something wrong or why doesn't it work?
Just wanted to say multi monitor is now working here, my HDMI recorder was the culprit! If I directly connect the monitor I get the ".1" monitor modes to select a screen on the second monitor.