[comp.sys.mac.programmer] TN261-68030 CACHES

craig.treleaven@canremote.uucp (CRAIG TRELEAVEN) (11/02/90)

UN:
   Tech Note 261 describes how to turn on and off the instruction
and data caches on the 68030.  And it works fine on a 68030.  But
I have two questions:

   1) The TN says: "make sure that the _HWPriv ($198) trap is
implemented, or your program will crash."  And yes indeed, it does
crash on a 68000.  But HOW does one check to see if a trap is
implemented?  I've looked at _NGetTrapAddress but it seems to
blithely return an address no matter what trap number you feed it.
Am I missing somethine obvious?

   2) What happens on a 68020 (or a 68040, for that matter)?  Does
the _HWPriv trap work on other processors?  If not, how does one
turn off the instruction cache on other machines.

   Craig.Treleaven@CanRemote.UUCP

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