Can you use the iBook G3's keyboard on an iBook G4? Yes, but you probably don't want to, as you'll likely have a busted ribbon and scratch your G4 iBook's screen. Can you use a G4's keyboard on a G3? Not practically speaking unless you hack in more ribbon. Skip to Conclusion now.

UPDATE: Because of the length of the ribbon, you cannot use the iBook G4's keyboard in the iBook G3. "Cannot use" might be a little harsh, but you can't seat the G4 keyboard with the latches in the G3 which means the keyboard floats around and you can't close the lid Yes, that's right, this means my donor iBook G3 500 has an unseated keyboard sitting in it right now. I imagine the danged thing works (not plugged in right now, I'm afraid, and the battery's dead), but it's not exactly a great mobile computer now. I take that back -- I guess I've now got an unseated, broken keyboard in the G3 now. Luckily the thing's just my print server on a KVM, but, um, fair warning. Your donor G3 is going to be worse for the operation, so try and order an extra G3 keyboard if you try this idiotic idea.

Back to the unecessary exposition: I have a bad habit of taking my Macs apart and not putting them back together so well. Well, chalk up another. As I've ranted here before, I've really disliked the keyboard on my iBook G4, which repeats h's and drops spaces and is a particular shame, since I liked the keyboard on my iBook G3 about as much as I've ever liked a laptop keyboard. I'd thought about swapping, but a quick call to Small Dog, who told me the keyboards aren't interchangable, talked me out of it.

Lately, however, my G4's keyboard has started taking over my computer periodically, typing swx2's, tabbing like mad, closing windows, and pushing the screen's brightness up as high as it'll go. Replacements are $100 so I thought I'd check out the G3 keyboard which is still hooked up to an older iBook that's been the victim of many experiments. Turns out the keyboards are dead ringers for each other when held on top of one another -- that is, all the keys are in the same places, as are the latches, etc, even the ribbon's final connector to the motherboard. The external differences are limited to color, feel, and the length and location of the ribbon/wire that goes between the boards. The keys do latch much differently and use metal parts under the key covers on the G4's keyboard, I've noticed but, again, feel horrible.

Could they possibly be differently wired? With this many simularities, I couldn't believe it. So out comes the G3 keyboard and I mad scientisted it into the G4, bending the ribbon something awful.

Conclusion: Yes, G3 iBook keyboards work in G4s. The ribbon plugs in and the keys are the same. You have to bend the ribbon that connects the keyboard to the iBook motherboard over itself, which is A Very Bad Idea (c), but it works. This also means the board bows out a bit to try and accomodate the extra space the ribbon needs, so the keys will likely be scratching my screen up soon as they'll rub when the screen's closed. The extra stress on the ribbon probably means the ribbon'll be borked soon as well.

So there you go. It works. Horrible idea. YMMV.