The clamshell iBook was the first Mac based on the new Unified Motherboard Architecture (UMA). The logicboard sported new Apple specific ASICs which supported the new standards (USB, FireWire, Ethernet 100mbit, Ultra DMA).
The integration of the controller chips "UniNorth" and "KeyLargo" shows the figure on the Japanese website Medicalmac, the link is a Google translation - or the Apple Developer Notes
The scalability of UMA systems makes it possible that future models can be built on same architecture, reducing development and production costs. For example: the AGP graphics can be accessed with 2x or 4x speed, The bus speed is adjustable from 66MHZ to more than 100MHZ - which is particularly useful for Overclockers.
It is a pity that the Clamshell series ended in 2001, so many possible features were not integrated. The logic board had e.g. still had free space for RAM banks and other interfaces.