1. I assume you are comparing 12" iBook with 12" PowerBook? obviously the 15" PowerBook has a better screen resolution...
What you have on the PowerBook which is not on the iBook :
- Faster processor / bus
- DVI output
- 64Mb of video RAM
- Audio Line-In input (iBook only has a microphone for audio input)
- Larger HD standard
- Faster HD (5200rpm)
- Superdrive (not available on 12" iBook
On larger models :
- Higher screen resolution
- Illuminated keyboard with ambient light sensor (pretty cool!)
- Firewire 800
- Optical audio in/out (on 17" PowerBook)
- Dual DVI link output to drive Apple 30" cinema display
Go to
http://www.apple.com/powerbook/specs.html for details... I guess it's the best source of information.
2. No idea
3. Yes
4. No (I suppose)