🚀 go-pugleaf

In article <19433@agate.BERKELEY.EDU> mit-vax!bloom-beacon!tut.cis.ohio-state.edu!mailrus!ames!pasteur!agate!garnet.berkeley.edu!gelobter gelobter@garnet.berkeley.edu writes:
>Can somebody tell me how to tell if my MacII has a PMMU in it
>without necessarily taking it apart?
>Michel Gelobter.

You can determine this in a few seconds as follows:

1.  Display the byte at memory location $12F as follows:
      If you have TMON, press the interrupt switch on the side of your Mac II
and open a Dump window to location $12E.  Read the second byte you see.
      If you have MacsBug, press the interrupt switch and type DM 12F.
      If you have neither, press the interrupt switch and type DM 12F to the
built-in debugger.  Read the first byte you see.

    If the byte is 03, you have a 68030-based Mac II, which has a built-in MMU.
    If the byte is 02, you have a 68020-based Mac II.  Read on further.

2.  Display the byte at memory location $CB1 analogously to above (in TMON you
have to open a Dump window to location $CB0).

    If the byte is 01, you do not have a PMMU.
    If the byte is 03, you have a PMMU.

Hope this helps.

				Waldemar Horwat
				waldemar@vx.lcs.mit.edu