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Ensures an objective copy of the bus address is kept, and forwarded to cards.

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This commit is contained in:
Thomas Harte 2018-06-08 20:12:15 -04:00
parent 744c35b617
commit fb4bb21bf6
1 changed files with 7 additions and 6 deletions
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13
Machines/AppleII/AppleII.cpp
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@ -205,7 +205,7 @@ class ConcreteMachine:
return &speaker_;
}
forceinline Cycles perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
forceinline Cycles perform_bus_operation(const CPU::MOS6502::BusOperation operation, const uint16_t address, uint8_t *const value) {
++ cycles_since_video_update_;
++ cycles_since_card_update_;
cycles_since_audio_update_ += Cycles(7);
@ -232,21 +232,22 @@ class ConcreteMachine:
d000 to e000 : the low ROM area, which can contain indepdently-paged RAM with a language card
e000 onward : the rest of ROM, also potentially replaced with RAM by a language card
*/
uint16_t accessed_address = address;
MemoryBlock *block = nullptr;
if(address < 0x200) block = &memory_blocks_[0];
else if(address < 0xc000) {
if(address < 0x6000 && !isReadOperation(operation)) update_video();
block = &memory_blocks_[1];
address -= 0x200;
accessed_address -= 0x200;
}
else if(address < 0xd000) block = nullptr;
else if(address < 0xe000) {block = &memory_blocks_[2]; address -= 0xd000; }
else { block = &memory_blocks_[3]; address -= 0xe000; }
else if(address < 0xe000) {block = &memory_blocks_[2]; accessed_address -= 0xd000; }
else { block = &memory_blocks_[3]; accessed_address -= 0xe000; }
bool has_updated_cards = false;
if(block) {
if(isReadOperation(operation)) *value = block->read_pointer[address];
else if(block->write_pointer) block->write_pointer[address] = *value;
if(isReadOperation(operation)) *value = block->read_pointer[accessed_address];
else if(block->write_pointer) block->write_pointer[accessed_address] = *value;
} else {
// Assume a vapour read unless it turns out otherwise; this is a little
// wasteful but works for now.