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Ensured the PIA timer resumes its normal tick rate after being read; fixed those spaces that had crept in where tabs should be.

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This commit is contained in:
Thomas Harte 2015-08-10 16:55:16 +01:00
parent 42677f5f83
commit aebf636528
3 changed files with 41 additions and 31 deletions
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56
Machines/Atari2600.cpp
View File

@ -145,10 +145,10 @@ void Machine::output_pixels(int count)
// update hmove // update hmove
if (!(_horizontalTimer&3) && _hMoveFlags) { if (!(_horizontalTimer&3) && _hMoveFlags) {
for(int c = 0; c < 5; c++) { for(int c = 0; c < 5; c++) {
if ((_hMoveCounter^8^(_objectMotion[c] >> 4)) == 0xf) _hMoveFlags &= ~(1 << c); if ((_hMoveCounter^8^(_objectMotion[c] >> 4)) == 0xf) _hMoveFlags &= ~(1 << c);
if (_hMoveFlags&(1 << c)) _objectCounter[c] = (_objectCounter[c]+1)%160; if (_hMoveFlags&(1 << c)) _objectCounter[c] = (_objectCounter[c]+1)%160;
} }
_hMoveCounter = (_hMoveCounter-1)&0xf; _hMoveCounter = (_hMoveCounter-1)&0xf;
} }
@ -206,8 +206,8 @@ void Machine::output_pixels(int count)
get_output_pixel(&_outputBuffer[_lastOutputStateDuration * 4], 159 - _horizontalTimer); get_output_pixel(&_outputBuffer[_lastOutputStateDuration * 4], 159 - _horizontalTimer);
// increment all graphics counters // increment all graphics counters
for(int c = 0; c < 5; c++) for(int c = 0; c < 5; c++)
_objectCounter[c] = (_objectCounter[c]+1)%160; _objectCounter[c] = (_objectCounter[c]+1)%160;
} }
// assumption here: signed shifts right; otherwise it's just // assumption here: signed shifts right; otherwise it's just
@ -266,7 +266,7 @@ int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t add
case 0x07: returnValue &= 0x3f; break; // player / player, missile / missile collisions case 0x07: returnValue &= 0x3f; break; // player / player, missile / missile collisions
} }
} else { } else {
const uint16_t decodedAddress = address & 0x3f; const uint16_t decodedAddress = address & 0x3f;
switch(decodedAddress) { switch(decodedAddress) {
case 0x00: _vSyncEnabled = !!(*value & 0x02); break; case 0x00: _vSyncEnabled = !!(*value & 0x02); break;
case 0x01: _vBlankEnabled = !!(*value & 0x02); break; case 0x01: _vBlankEnabled = !!(*value & 0x02); break;
@ -328,10 +328,10 @@ int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t add
case 0x28: case 0x28:
case 0x29: case 0x29:
if (!(*value&0x02) && _missileGraphicsReset[decodedAddress - 0x28]&0x02) if (!(*value&0x02) && _missileGraphicsReset[decodedAddress - 0x28]&0x02)
_objectCounter[decodedAddress - 0x26] = _objectCounter[decodedAddress - 0x28]; // TODO: +3 for normal, +6 for double, +10 for quad _objectCounter[decodedAddress - 0x26] = _objectCounter[decodedAddress - 0x28]; // TODO: +3 for normal, +6 for double, +10 for quad
_missileGraphicsReset[decodedAddress - 0x28] = *value; _missileGraphicsReset[decodedAddress - 0x28] = *value;
break; break;
case 0x2a: case 0x2a:
_vBlankExtend = true; _vBlankExtend = true;
@ -339,12 +339,12 @@ int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t add
_hMoveFlags = 0x1f; _hMoveFlags = 0x1f;
break; break;
case 0x2b: case 0x2b:
_objectMotion[0] = _objectMotion[0] =
_objectMotion[1] = _objectMotion[1] =
_objectMotion[2] = _objectMotion[2] =
_objectMotion[3] = _objectMotion[3] =
_objectMotion[4] = 0; _objectMotion[4] = 0;
break; break;
} }
} }
// printf("Uncaught TIA %04x\n", address); // printf("Uncaught TIA %04x\n", address);
@ -354,15 +354,25 @@ int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t add
if ((address&0x1280) == 0x280) { if ((address&0x1280) == 0x280) {
if(isReadOperation(operation)) { if(isReadOperation(operation)) {
switch(address & 0xf) { switch(address & 0xf) {
case 0x04: returnValue &= _piaTimerValue >> _piaTimerShift; break; case 0x04:
case 0x05: returnValue &= _piaTimerStatus; _piaTimerStatus &= ~0x40; break; returnValue &= _piaTimerValue >> _piaTimerShift;
if(_writtenPiaTimerShift != _piaTimerShift) {
_piaTimerShift = _writtenPiaTimerShift;
_piaTimerValue <<= _writtenPiaTimerShift;
}
break;
case 0x05:
returnValue &= _piaTimerStatus;
_piaTimerStatus &= ~0x40;
break;
} }
} else { } else {
switch(address & 0x0f) { switch(address & 0x0f) {
case 0x04: _piaTimerShift = 0; _piaTimerValue = *value << 0; _piaTimerStatus &= ~0xc0; break; case 0x04: _writtenPiaTimerShift = _piaTimerShift = 0; _piaTimerValue = *value << 0; _piaTimerStatus &= ~0xc0; break;
case 0x05: _piaTimerShift = 3; _piaTimerValue = *value << 3; _piaTimerStatus &= ~0xc0; break; case 0x05: _writtenPiaTimerShift = _piaTimerShift = 3; _piaTimerValue = *value << 3; _piaTimerStatus &= ~0xc0; break;
case 0x06: _piaTimerShift = 6; _piaTimerValue = *value << 6; _piaTimerStatus &= ~0xc0; break; case 0x06: _writtenPiaTimerShift = _piaTimerShift = 6; _piaTimerValue = *value << 6; _piaTimerStatus &= ~0xc0; break;
case 0x07: _piaTimerShift = 10; _piaTimerValue = *value << 10; _piaTimerStatus &= ~0xc0; break; case 0x07: _writtenPiaTimerShift = _piaTimerShift = 10; _piaTimerValue = *value << 10; _piaTimerStatus &= ~0xc0; break;
} }
} }
// printf("Uncaught PIA %04x\n", address); // printf("Uncaught PIA %04x\n", address);

4
Machines/Atari2600.hpp
View File

@ -37,7 +37,7 @@ class Machine: public CPU6502::Processor<Machine> {
// the timer // the timer
unsigned int _piaTimerValue; unsigned int _piaTimerValue;
unsigned int _piaTimerShift; unsigned int _piaTimerShift, _writtenPiaTimerShift;
uint8_t _piaTimerStatus; uint8_t _piaTimerStatus;
// playfield registers // playfield registers
@ -67,7 +67,7 @@ class Machine: public CPU6502::Processor<Machine> {
bool _vSyncEnabled, _vBlankEnabled; bool _vSyncEnabled, _vBlankEnabled;
bool _vBlankExtend; bool _vBlankExtend;
uint8_t _hMoveCounter, _hMoveFlags; uint8_t _hMoveCounter, _hMoveFlags;
uint8_t _objectCounter[5], _objectMotion[5]; uint8_t _objectCounter[5], _objectMotion[5];
enum OutputState { enum OutputState {
Sync, Sync,

12
Outputs/CRT.cpp
View File

@ -101,14 +101,14 @@ CRT::SyncEvent CRT::get_next_vertical_sync_event(bool vsync_is_requested, int cy
SyncEvent proposedEvent = SyncEvent::None; SyncEvent proposedEvent = SyncEvent::None;
int proposedSyncTime = cycles_to_run_for; int proposedSyncTime = cycles_to_run_for;
// will an acceptable vertical sync be triggered? // will an acceptable vertical sync be triggered?
if (vsync_is_requested && !_is_in_vsync) { if (vsync_is_requested && !_is_in_vsync) {
if (_sync_capacitor_charge_level >= _sync_capacitor_charge_threshold) {// && _rasterPosition.y >= (kCRTFixedPointRange * 7) >> 3) { if (_sync_capacitor_charge_level >= _sync_capacitor_charge_threshold) {// && _rasterPosition.y >= (kCRTFixedPointRange * 7) >> 3) {
proposedSyncTime = 0; proposedSyncTime = 0;
proposedEvent = SyncEvent::StartVSync; proposedEvent = SyncEvent::StartVSync;
_did_detect_vsync = true; _did_detect_vsync = true;
} }
} }
// have we overrun the maximum permitted number of horizontal syncs for this frame? // have we overrun the maximum permitted number of horizontal syncs for this frame?
if (!_is_in_vsync) { if (!_is_in_vsync) {
@ -346,21 +346,21 @@ void CRT::output_sync(int number_of_cycles)
void CRT::output_blank(int number_of_cycles) void CRT::output_blank(int number_of_cycles)
{ {
bool _vsync_requested = _is_receiving_sync; bool _vsync_requested = _is_receiving_sync;
_is_receiving_sync = false; _is_receiving_sync = false;
advance_cycles(number_of_cycles, false, _vsync_requested, false, Type::Blank, nullptr); advance_cycles(number_of_cycles, false, _vsync_requested, false, Type::Blank, nullptr);
} }
void CRT::output_level(int number_of_cycles, const char *type) void CRT::output_level(int number_of_cycles, const char *type)
{ {
bool _vsync_requested = _is_receiving_sync; bool _vsync_requested = _is_receiving_sync;
_is_receiving_sync = false; _is_receiving_sync = false;
advance_cycles(number_of_cycles, false, _vsync_requested, false, Type::Level, type); advance_cycles(number_of_cycles, false, _vsync_requested, false, Type::Level, type);
} }
void CRT::output_data(int number_of_cycles, const char *type) void CRT::output_data(int number_of_cycles, const char *type)
{ {
bool _vsync_requested = _is_receiving_sync; bool _vsync_requested = _is_receiving_sync;
_is_receiving_sync = false; _is_receiving_sync = false;
advance_cycles(number_of_cycles, false, _vsync_requested, false, Type::Data, type); advance_cycles(number_of_cycles, false, _vsync_requested, false, Type::Data, type);
} }