====== Memory Map ======

^ Use  ^  Start - End  ^ Implementation  ^
| RAM |  0000 - DFFF  | [[56K NVRAM]] |
| ::: |  D000 - D0FF  | ASSIST09 working RAM, stacks and vector copies |
| I/O |  E000 - E3FF  | [[Main Bus Select 0 1K]] |
| ::: |  E400 - E7FF  | [[Main Bus Select 1 1K]] |
| ::: |  E800 - EAFF  | unassigned |
| ::: |  EB00 - EBFF  | [[ACIA Select 256b]] |
| ::: |  EC00 - EEFF  | unassigned |
| ::: |  EF00 - EFFF  | [[Memory Latch Select 256b]] |
| ROM |  F000 - FFFF  | [[EEPROM 4K]] |
| ::: |  F000 - F3FF  | [[ASSIST09]] Expansion ROM area (unused) |
| ::: |  F800 - FFFF  | [[ASSIST09]] |
| MPU |  FFF0 - FFF1  | HD6390 Illegal Opcode/Divide By Zero Trap vector (FFD4) |
| ::: |  FFF2 - FFF3  | SWI3 vector (FFD8) |
| ::: |  FFF4 - FFF5  | SWI2 vector (FFDC)|
| ::: |  FFF6 - FFF7  | /FIRQ vector (FFE0) |
| ::: |  FFF8 - FFF9  | /IRQ vector (FFE4) |
| ::: |  FFFA - FFFB  | SWI vector (FFE8) |
| ::: |  FFFC - FFFD  | /NMI vector (FFEC) |
| ::: |  FFFE - FFFF  | /RESET vector (F837) |

The 2.0 board is hard wired for "Exxx" selects in the map above.

The subsequent version has jumpers to locate the I/O block

These use J3 select jumper for 8xxx - Exxx address select range

Return to [[:SST-6809:]]