Not especially similar, aside from the bus and CPU. IBM hardware of that era was straight-up PReP and later straight-up CHRP, but Apple never adopted either for

Not especially similar, aside from the bus and CPU. IBM hardware of that era was straight-up PReP and later straight-up CHRP, but Apple never adopted either for Old World Macs, and even New World Macs are an incompatible mix of the two.