I am connected via DVI to an ASUS PA278QV. There is an initial gray screen, but the video goes dark, the instant the CD starts spinning up. The mouse and keyboard seem to be alive.

A mini is incapable of producing output above FullHD. MorphOS is trying to match the resolution of your 2k display and fails (we've corrected this for 3.20).

Try holding the CTRL button when you boot, this will force a lower resolution screen mode. From there, go to Settings / Screens and make sure to pick a mode that's no more than 1920x1080, ideally 16bit color since the mini lacks the required graphics ram to comfortably go higher.

At FullHD 24bit would still be o.k. of you have a "silent upgrade" Mini with 64MB VRAM. On 32MB models 16bit is the way to go.

Going beyond FullHD is possible within the "Monitors" prefs by reducing the refresh rate and shortening sync times.
ASUS claims that the screen will go down to 46Hz which might not be low enough to reach the native 2560x1440.

About 2 years ago I did some similar tests with my Phillips screens that stop at 48Hz (spec says 50Hz) on both a Radeon9000 and Voodoo3 (yep VGA) and I did come close but never close enough to have it useable at that res.

[ Edited by Kronos 24.01.2026 - 09:10 ]

Quote:

With the RV280 embedded GPU in the Mac mini, you really don't want to go past any 2048 pixel wide screens as you lose all the acceleration capabilities past that width ... Either way. The Mac minis back then weren't really intended to be used past 1080p and even with that resolution the non SU update models start to struggle due to some apparent bugs in the HDMI transceiver.
The latest MorphOS Radeon driver updates try to take that issues into account and limit the pixel clock as well as the max resolution accordingly.
Even with R300 class GPUs in PBooks, you are limited to 2656 wide screens due to some weird bug?/scissor design decision but at least you can go 2560x1440@60Hz WQHD/QHD on the external output if it is prepared for that (aka Duallink DVI capable).