Debian 12 PPC64 (MintPPC64) Dual Monitor

Hi,

I have a late 2005 Power Mac G5 Quad running Debian 12 PPC64 with the MintPPC64 layer on it. I have two Apple 20" Cinema displays connected to the system via the two DVI ports supplied by my single nVidia GeForce 6600 video card (supported by the "nouveau" driver).

Under Mac OS X (Sorbet) Leopard, both monitors are active and used as one extended desktop. Under Mint/Debian, only one is in use.

I have researched extensively online and tried all sorts of solutions, largely involving xrandr and xset. Nothing has worked so far. xrandr reports two displays, which it names DVI-I-1 and DVI-I-2.

The usual prescription:

xrandar --output DVI-I-2 --auto

is accepted and executed without error, but the monitor stubbornly stays off. Correction: the power light stays on, but the screen stays off.

Constructions like:

xrandr --output DVI-I-1 --auto --output DVI-I-2 --auto --rightof DVI-I-1

also executes without error, but there is no change in the screen... it stays off.

The system understands that there is a second monitor... the mouse cursor will disappear onto the second one. If I set it as primary, windows will open on that screen, but because it is off, I can't see them. I have occasionally managed to snag them and drag them back to the screen that IS on.

It is like everything is working logically, but physically, nothing is turning the screen on. The physical screen doesn't seem to be connected to the logical one.

I am stumped at this point.

Any and all pointers much appreciated.

Regards,
Michael

As the system is booting, both displays are on, but the second one turns off as the system boots.

I don't know if this is a limitation of the nouveau driver (can only support one physical monitor) or something deeper.

On September 2, 2025 6:01:31 PM EDT, Riccardo Mottola <riccardo.mottola@libero.it> wrote:

Hi,

Cedar Maxwell wrote:
Can anyone provide any guidance on how to install Debian onto an
OldWorld ROM Macintosh?

how old is oldworld?

I have a PMac 8200 which has been sitting for years unused. It was my development box for MkLinux, but I think it is perhaps to say goodbye to it, attempts reviving this interesting kernel failed, also by myself, since hacking in kernel code to support ext2 failed :( a pity.

It is really old.. first PCI series and so has proper OpenFirmware (v1 if memory serves, those that default to serial console) but has PPC 601 CPU. A strange mix of Apple harware and a PPC cpu which is still POWER compliant... old times!

Is that CPU still supported in the kernel or is it dead? I remember that some OS remove it, but I don't remember which.

Riccardo

Debian 12 PPC64 (MintPPC64) Dual Monitor - Only One Being Used