Microtan technical reference
Memory map
Address ranges used by RAM, ROM, display memory, sound and I/O.
| Address range | Function |
|---|---|
0000–003F | System variables |
0040–00FF | Unused, except by BASIC |
0100–01FF | Processor stack |
0200–03FF | Display |
0400–AFFF | RAM |
BC00–BC01 | First AY-3-8910 sound chip |
BC02–BC03 | Second AY-3-8910 sound chip |
BC04 | Space Invasion sound |
BFC0–BFCF | First 6522 VIA |
BFD0–BFD3 | Serial I/O; not implemented in the legacy Windows emulator |
BFE0–BFEF | Second 6522 VIA |
BFF0 | Read: chunky graphics on Write: reset keyboard interrupt flag |
BFF1 | Write: start delayed NMI |
BFF2 | Write: hexadecimal-keypad column |
BFF3 | Read: last ASCII-keyboard key or hexadecimal-keypad row Write: chunky graphics off |
C000–E7FF | BASIC interpreter ROM |
F000–F7FF | XBUG ROM |
F800–FFFF | TANBUG ROM |