I am not new to linux in general, but I am new to Debian, and installing it on PowerPC. I recently installed Debian for PowerPC on my old iMac. I do not know if it is a G3 or G4, but it is one of the CRT models. The install went through fine, but then I type "Linux" at the boot prompt, and it begins loading everything and printing status messages to the screen. But, when it is done loading, the screen goes entirely black. I even left it over night to make sure it didn't just have to load something to do with the display, but it was still black in the morning. I read somewhere else that it can be fixed by editing the xorg.conf, but how am I supposed to do that without the display? Please help me get this working! Thanks in advance!

If it is a G3 iMac then it is a know issue. Here is the fix:Taken from here.

I tried that key combination multiple times, nothing happened. Any other ideas?

No, that worked for me on my G3 iMac.

When exactly do I press it? When the screen turns black?

After the screen goes black wait a while, until the harddisk is not active anymore, so that you can be sure the system is up and running. Then press the key combination.

I just booted it again, waited for the HDD activity to die down, and then waited a bit longer. I pressed the key combo, and I heard some more HDD activity, but no command prompt. I waited a couple more minutes, and again, HDD activity as soon as I pressed the keys, but still no command prompt. I have no clue why it is not working.

It is some time ago, so I don't remember for sure, but does the bootloader has a line where you can type in a kernel you want to boot? If so type in the default kernel and add a 1 and the end of the line, so that the system does not start the graphical environment. Something that it looks like that Then proceed with editing xorg.conf.
Alternatively, boot to a rescue shell from your installer CD, mount the /-partition and edit the file.

I did what you said, it gives me the command prompt. I will edit the file. One more thing. The display seems misaligned. The top left corner's text has too much of a border, and it too far away from the screen edge. The first few letters of the bottom left corner's text have disappeared beyond the boundaries of the screen. Is this a software or a hardware problem?

GAHHHH! There is no X11 folder inside /etc/ !!!!

Have you booted from the install disc or modified the bootloader's command-line? If you use the install disc you have to mount the harddisk , for example to /mnt, and then edit the file inside /mnt/etc, not /etc.

OK, I found it, but there was no xorg.conf. I made an xorg.conf with the monitor and module blocks, rebooting now to see if it worked.

I rebooted it, and it booted to a command prompt without intervention by me. I typed "startx" and it said that the monitor needed an identifier in the xorg.conf. I tried "Monitor0" but now it gives me the black screen again. What should the monitor identifier be, and do I need the vendorname and modelname parameters?

When you have booted to the command-line just use to generate a template file named xorg.conf.new in the current directory. That file should almost be appropriate for that machine, just do the needed edits and copy it to /etc/X11/xorg.conf. After that it should work.

I'll try that, and is there anything I can do about the skewed display?