• EMMU1 tells that MMU type 1 is emulated (on PowerMacs).

• 68040 processor has a built-in PMMU.

• 68030 processor has a built-in PMMU.

• 68851 PMMU is an optional mmu to use with a 68020 processor. It manages paged memory.

• AMU (address management unit) is the standard mmu with a 68020 processor. It does not manage paged memory.

• NoMMU tells that no memory management unit is present.