🚀 go-pugleaf

   In article <2345@oakhill.UUCP> shebanow@oakhill.UUCP (Mike Shebanow) writes:
    In article <231@ssp1.idca.tds.philips.nl> roelof@idca.tds.PHILIPS.nl
    (R. Vuurboom) writes:
    
    >I've noticed that motorola has moved from instruction continuation
    >(68010-30) to instruction restart (68040). So they no longer support
    >virtual machines. (Must be the processors got tired of puking their
    >insides all over the stack. :-)
    >
    >[...]
    
    You can still emulate virtual machines using instruction restart.  All 
    you have to do is simply interpret the instruction which faulted :-\
    That is, when the machine takes the exception, the stack frame will point
    to the offending instruction.

Forgive me for showing my ignorance, but, doesn't instruction continuation
enable features such as dynamic stack allocation?  Are we doomed to
return to the antiquated "stack probe"?  Does this mean that 68030
(user mode) software will not always work correctly on the 68040?
What about page faults?  Is the operating system *really* expected 
to include an instruction set interpreter so it can simulate
instruction continuation?  The 386 is suddenly starting to look good
me.

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Scott Amspoker
Basis International, Albuquerque, NM
505-345-5232