[comp.sys.mac] why can't MacOS use National Semiconductor 8MB memory board as core?

pkahn@meridian.ads.com (Phil Kahn) (06/05/88)

We just got a National Semiconductor 8MB Nubus memory board.
Though this board can be used as main memory when under A/UX, it seems
only usable under MacOS as a ram disk.  We need a very large memory
under MacOS (we cannot yet use A/UX, but that's another nasty story)
and we were hoping that 16MB was achievable (8MB in SIMMS and 8MB NSC
board). This incredibly large memory is needed because we are
developing a very extensible vision system, and data space
requirements are typically very large. A/UX could offset this problem
with virtual memory, but features in MacOS which we use (i.e., some
managers and other stuff) don't appear to be available in A/UX. (Is
this true? That seems to me to be the concensus of what I've seen on
the net. If not, please correct me.)  In any event, even if we wanted
to use the NSC board under MacOS, we need to get a ROM update to avoid
the current limitation on Nubus address space...
 
phil...