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.