memory-mapped MULTIBUS boards and XENIX ? ?

[th at houxd.UUCP]

Help!

     I've got a MULTIBUS development system which runs under XENIX.
I've also purchased, for this system, some memory-mapped boards ( an
analog input card and a single board array processor ).

     My problem is this:  these boards are configured into the system
to look like ram ( they have PHYSICAL memory addresses ) but XENIX 
forces ( ? ) me to stay in a LOGICAL addressing environment.

     How can I read from / write to physical memory from XENIX or a 
C program ?   What does it take ?

     Any advice / guidance will be appreciated.  Reply in this
newsgroup, net.followup, btl.followup or by mail  ... ihnp4!houxd!th

                            Thanks,

                            Tom Hartnett  ( BTL Holmdel NJ )
                                          ( 201 949-3417 )