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65032: Re-designed 65c832

As of 1990, a 65c832 was supposed to have 32bit mode registers like this:



_________________________________________________________________
|               |               |               |               |
|     8bits     |     8bits     |     8bits     |     8bits     |
|High byte      |               |               |       Low byte|
-----------------------------------------------------------------

_________________________________________________________________
|                          X Register                           |
-----------------------------------------------------------------
_________________________________________________________________
|                          Y Register                           |
-----------------------------------------------------------------
_________________________________________________________________
|                          Accumularor                          |
-----------------------------------------------------------------

_________________________________________________________________
|               |Program Bank   |       Program Counter         |
|  Reserved (0) |Register (PBR) |                               |
-----------------------------------------------------------------
_________________________________________________________________
|         Reserved (0)          |       Direct Register         |
-----------------------------------------------------------------
_________________________________________________________________
|         Reserved (0)          |        Stack Pointer          |
-----------------------------------------------------------------
_________________________________________________________________
|  Reserved (0) |Date Bank      |          Reserved (0)         |
|               |Register (DBR) |                               |
-----------------------------------------------------------------

                                                _________________
                                                |    Status     |
                                                -----------------


Since I'm after a 64bit bus (32bit address & separate 32bit data), I want to
make some changes to the address logic registers. After the changes they'd
look like this:

_________________________________________________________________
|                        Program Counter                        |
-----------------------------------------------------------------

-----------------------------------------------------------------
|             Program Bank Register             |  Reserved (0) |
-----------------------------------------------------------------
_________________________________________________________________
|                Direct Register                |  Reserved (0) |
-----------------------------------------------------------------
_________________________________________________________________
|                         Stack Pointer                         |
-----------------------------------------------------------------
_________________________________________________________________
|              Stack Bank Register              |  Reserved (0) |
-----------------------------------------------------------------
_________________________________________________________________
|              Date Bank Register               |   Reserved (0)|
-----------------------------------------------------------------

I also want to make the status register a full 32 bits. These modifications
should even allow for multitasking of the old 8bit programs. Are their any
reasony why I shouldn't make these expansions?