Alrighty, here's the skinny on what I've been learning with my Powerbook 800 and clamshell mode (The second display is an NEC FP955 CRT monitor with a DVI-A input, and I'm using OS X 10.1.5) Supposedly, to work in clamshell mode, with your laptop's cover closed and keyboard, video, and mouse plugged in, you will need to enable both displays, and then in system prefs/Display, you must make both displays the same resolution and colour depth, then check the Mirror button, so that the same screen displays on both displays. At this point you close your laptop, (which will enter sleep mode, and turn off both displays), then push a button or click the mouse to exit Sleep mode. The Laptop display will remain disabled and the secondary monitor will become the main display. Now up to this point, we had set the same resolution for both screens. If you're using a TiBook like me, you're stuck in 1024x768 max, since the monitor wont support the 15.2 inch odd ratio screen. (If you have an Apple cinema display, this is not an issue, but you're still stuck at the Laptop's highest resolution, 1280x1024 (1152x864 on a Pre DVI TiBook))
Here's the discovery I just made, that makes things a bit more hopeful:
Push the Mirror Display button on the laptop keyboard (F7)
This will Mirror both displays but will NOT change the resolution of the Laptop display. The secondary monitor will conform to the Laptop's resolution, and in the case of a TiBook, it will have black bands on the top and bottom, due to the odd aspect ratio. But! Once you push the mirror button, then close the laptop and exit sleep mode, you will be able to change the Resolution of the secondary display to any of its native settings. True Clamshell mode, I love thee.
Hope this makes sense, even though it may not pertain to the original topic of this post, I wanted to share it anyway (I like finding things out for myself)
Nosh!
Oh, and a side note, I was using a standard Pro Keyboard (black keys) without a power button on it, so that may not be an issue.
