* '''JDB''' (Junction Data Bus), one of two ICs making up the I/O Adapter, connecting the data signals from the system bus and the I/O bus
* '''Kiwi'''. The Kiwi IC is a very large-scale IC that incorporates the functions of the YANCC IC used in the Macintosh Quadra 700 and 950 computers along with the bus transceivers and several driver ICs. The Kiwi IC provides an interface to the MC68040 on one side and a NuBus interface on the other side.
* '''MCU''' (Memory Control Unit), a custom IC that connects to the system bus and controls regular and burst-mode data transfers to and from the main RAM and ROM