Fresh buster install: Font/DPI broken in Xfce

[te36]

trying to revive old AMD motherboard as server, so single x16 PCIe slot reserved for RAID card. Let's use an old PCI mach64 card with VGA output.

1) Installed debian fresh from: https://cdimage.debian.org/images/unoff ... so-hybrid/ Xfce
2) install xserver-xorg-video-mach64

Starting X the VGA display goes to 1024x768, but login screen shows username/password field almost full screen. after login, all fonts are about 1 pixel high, but the icons are gigantic. Of course, this is completely unusable.

Plugging in modern, HDMI PCIe card, everything works fine.

I guess i could continue to search long and hard to find all the parameters for some Xorg.conf to do a fixup on these problems, but:

a) Shouldn't this work better out of the box ?
b) I can't even fathom how to bring together the gigantic desktop icons and the microscopic fonts. If the system was confused about the DPI of the display, both should be large or small...

Of course, installation runs also take a while, so not sure i want to repeat installing different desktops, rather look for diagnostics/troubleshooting tips. The debian wiki alas says nothing about this.

[Head_on_a_Stick]

Check the kernel driver in use for the video card.