>
>   TV> No, but the 68030 on the Daystar board has a built-in
>     > PMMU and does not depend on the presence of a 68851.
>
>Does plugging in the upgrade disable the 68851 (if present),
>or does software just 'ignore it'?

I haven't seen one of these in years, so my memory may be faulty.  I 
seem to recall that the 68030, since it included the 68851 
functionality had more pins than the 68020.  The Daystar board mapped 
those pins to the equivalent pins in the 68851.  The Daystar board 
fit into both the 68020 and 68851 sockets on the Mac II motherboard. 
So, if the Daystar board is installed into the Mac II, neither a 
68020 nor a 68851 are installed in the machine.

My (possibly faulty) memory also says that the 68030, since it 
includes the 68851, couldn't use the support chip even if they are 
installed on the same board.  So the hardware just ignores it.

-- 
Eric Damien Berna
eric@thiel.com