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Address Range           Description
-----------------       ------------------------------------------------
00 0000 - 03 FFFF       256K Chip RAM (A1000 Chip RAM,
                            1st 256K for A500/A2000)
04 0000 - 07 FFFF       256K bytes of Chip RAM (2nd 256K for A500/A2000)
08 0000 - 0F FFFF       512K  Extended chip RAM  (to 1 MB for A2000).
10 0000 - 1F FFFF       Reserved. Do not use.
20 0000 - 9F FFFF       Primary  8 MB Auto-config space .
A0 0000 - BE FFFF       Reserved. Do not use.
BF D000 - BF DF00        8520-B  (access at even-byte addresses only)
    -         -
BF E001 - BF EF01        8520-A  (access at odd-byte addresses only)
    -         -
                        The underlined digit chooses which of the
                         16 internal registers  of the 8520 is to be
                        accessed.  See Appendix F.
C0 0000 - DF EFFF       Reserved.  Do not use.
   |
   | C0 0000 - D7 FFFF  Internal expansion (slow) memory (on some systems).
   |
   | D8 0000 - DB FFFF  Reserved.  Do not use.
   |
   | DC 0000 - DC FFFF  Real time clock (not accessable on all systems).
   |
   | DF F000 - DF FFFF  Chip registers.  See  Appendix A  and  Appendix B .
   +--
E0 0000 - E7 FFFF       Reserved.  Do not use.
E8 0000 - E8 FFFF        Auto-config space .  Boards appear here before
                        the system relocates them to their final address.
E9 0000 - EF FFFF       Secondary  auto-config space  (usually 64K I/O
                        boards).
F0 0000 - FB FFFF       Reserved.  Do not use.
FC 0000 - FF FFFF       256K System ROM.