Editing Macintosh II (section)

=== CPU ===
The Macintosh II is built around the [[Motorola 68020]] processor operating at 16 [[Hertz|MHz]], teamed with a [[Motorola 68881]] [[floating-point unit]]. The machine shipped with a socket for an optional [[Motorola 68851]] [[Memory management unit|MMU]], but an "Apple HMMU Chip" (VLSI VI475 chip) was installed by default and could not implement [[virtual memory]] (instead, it translated 24-bit addresses to 32-bit addresses for the Mac OS, which would not be [[32-bit clean]] until [[System 7]]).<ref name=":1">{{Cite book |url=https://archive.org/details/apple-guide-macintosh-family-hardware/page/n513/mode/2up?view=theater |title=Guide to the Macintosh family hardware |date=1990 |publisher=Addison-Wesley Pub. Co |isbn=978-0-201-52405-5 |editor-last=Apple Computer |edition=2nd |location=Reading, Mass |pages=476-478}}</ref>