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Made a very basic attempt to emulate tape output.

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This commit is contained in:
Thomas Harte 2016-01-24 18:20:55 -05:00
parent 1819e7b9cc
commit 96c946b8af
2 changed files with 98 additions and 52 deletions
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134
Machines/Electron/Electron.cpp
View File

@ -117,12 +117,12 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
if(isReadOperation(operation))
{
*value = _tape.get_data_register();
_tape.clear_interrupts(Interrupt::TransmitDataEmpty);
_tape.clear_interrupts(Interrupt::ReceiveDataFull);
}
else
{
_tape.set_data_register(*value);
_tape.clear_interrupts(Interrupt::ReceiveDataFull);
_tape.clear_interrupts(Interrupt::TransmitDataEmpty);
}
break;
case 0x5:
@ -606,7 +606,7 @@ void Speaker::set_is_enabled(bool is_enabled)
Tape
*/
Tape::Tape() : _is_running(false), _data_register(0), _delegate(nullptr) {}
Tape::Tape() : _is_running(false), _data_register(0), _delegate(nullptr), _output_bits_remaining(0), _last_posted_interrupt_status(0), _interrupt_status(0) {}
void Tape::set_tape(std::shared_ptr<Storage::Tape> tape)
{
@ -627,33 +627,36 @@ inline void Tape::get_next_tape_pulse()
inline void Tape::push_tape_bit(uint16_t bit)
{
_data_register = (uint16_t)((_data_register >> 1) | (bit << 10));
uint8_t old_interrupt_status = _interrupt_status;
if(_bits_since_start)
{
_bits_since_start--;
if(_bits_since_start == 7)
{
_interrupt_status &= ~Interrupt::TransmitDataEmpty;
_interrupt_status &= ~Interrupt::ReceiveDataFull;
}
}
else
evaluate_interrupts();
}
inline void Tape::evaluate_interrupts()
{
if((_data_register&0x3) == 0x1)
{
if((_data_register&0x3) == 0x1)
{
_interrupt_status |= Interrupt::TransmitDataEmpty;
_bits_since_start = 9;
}
if(_data_register == 0x3ff)
_interrupt_status |= Interrupt::HighToneDetect;
else
_interrupt_status &= ~Interrupt::HighToneDetect;
_interrupt_status |= Interrupt::ReceiveDataFull;
_bits_since_start = 9;
}
if(old_interrupt_status != _interrupt_status && _delegate) _delegate->tape_did_change_interrupt_status(this);
if(_data_register == 0x3ff)
_interrupt_status |= Interrupt::HighToneDetect;
else
_interrupt_status &= ~Interrupt::HighToneDetect;
if(_last_posted_interrupt_status != _interrupt_status)
{
_last_posted_interrupt_status = _interrupt_status;
if(_delegate) _delegate->tape_did_change_interrupt_status(this);
}
}
inline void Tape::clear_interrupts(uint8_t interrupts)
@ -665,43 +668,84 @@ inline void Tape::clear_interrupts(uint8_t interrupts)
}
}
inline void Tape::set_is_in_input_mode(bool is_in_input_mode)
{
_is_in_input_mode = is_in_input_mode;
}
inline void Tape::set_counter(uint8_t value)
{
_pulse_stepper = std::shared_ptr<SignalProcessing::Stepper>(new SignalProcessing::Stepper(1200, 2000000));
}
inline void Tape::set_data_register(uint8_t value)
{
_data_register = (uint16_t)((value << 2) | 1);
_output_bits_remaining = 9;
}
inline void Tape::run_for_cycles(unsigned int number_of_cycles)
{
if(_is_running && _is_enabled && _tape != nullptr)
if(_is_enabled)
{
while(number_of_cycles--)
if(_is_in_input_mode)
{
_time_into_pulse += (unsigned int)_pulse_stepper->step();
if(_time_into_pulse == _current_pulse.length.length)
if(_is_running && _tape != nullptr)
{
get_next_tape_pulse();
_crossings[0] = _crossings[1];
_crossings[1] = _crossings[2];
_crossings[2] = _crossings[3];
_crossings[3] = Tape::Unrecognised;
if(_current_pulse.type != Storage::Tape::Pulse::Zero)
while(number_of_cycles--)
{
float pulse_length = (float)_current_pulse.length.length / (float)_current_pulse.length.clock_rate;
if(pulse_length > 0.4 / 2400.0 && pulse_length < 0.6 / 2400.0) _crossings[3] = Tape::Short;
if(pulse_length > 0.4 / 1200.0 && pulse_length < 0.6 / 1200.0) _crossings[3] = Tape::Long;
}
if(_crossings[0] == Tape::Long && _crossings[1] == Tape::Long)
{
push_tape_bit(0);
_crossings[1] = Tape::Unrecognised;
}
else
{
if(_crossings[0] == Tape::Short && _crossings[1] == Tape::Short && _crossings[2] == Tape::Short && _crossings[3] == Tape::Short)
_time_into_pulse += (unsigned int)_pulse_stepper->step();
if(_time_into_pulse == _current_pulse.length.length)
{
push_tape_bit(1);
get_next_tape_pulse();
_crossings[0] = _crossings[1];
_crossings[1] = _crossings[2];
_crossings[2] = _crossings[3];
_crossings[3] = Tape::Unrecognised;
if(_current_pulse.type != Storage::Tape::Pulse::Zero)
{
float pulse_length = (float)_current_pulse.length.length / (float)_current_pulse.length.clock_rate;
if(pulse_length > 0.4 / 2400.0 && pulse_length < 0.6 / 2400.0) _crossings[3] = Tape::Short;
if(pulse_length > 0.4 / 1200.0 && pulse_length < 0.6 / 1200.0) _crossings[3] = Tape::Long;
}
if(_crossings[0] == Tape::Long && _crossings[1] == Tape::Long)
{
push_tape_bit(0);
_crossings[1] = Tape::Unrecognised;
}
else
{
if(_crossings[0] == Tape::Short && _crossings[1] == Tape::Short && _crossings[2] == Tape::Short && _crossings[3] == Tape::Short)
{
push_tape_bit(1);
_crossings[3] = Tape::Unrecognised;
}
}
}
}
}
}
else
{
while(number_of_cycles--)
{
if(_pulse_stepper->step())
{
_output_bits_remaining--;
if(!_output_bits_remaining)
{
_output_bits_remaining = 9;
_interrupt_status |= Interrupt::TransmitDataEmpty;
}
evaluate_interrupts();
_data_register = (_data_register >> 1) | 0x200;
}
}
}
}
}

16
Machines/Electron/Electron.hpp
View File

@ -33,8 +33,8 @@ enum ROMSlot: uint8_t {
enum Interrupt: uint8_t {
DisplayEnd = 0x04,
RealTimeClock = 0x08,
TransmitDataEmpty = 0x10,
ReceiveDataFull = 0x20,
ReceiveDataFull = 0x10,
TransmitDataEmpty = 0x20,
HighToneDetect = 0x40
};
@ -64,8 +64,8 @@ class Tape {
void set_tape(std::shared_ptr<Storage::Tape> tape);
inline uint8_t get_data_register() { return (uint8_t)(_data_register >> 2); }
inline void set_data_register(uint8_t value) {}
inline void set_counter(uint8_t value) {}
inline void set_data_register(uint8_t value);
inline void set_counter(uint8_t value);
inline uint8_t get_interrupt_status() { return _interrupt_status; }
inline void clear_interrupts(uint8_t interrupts);
@ -80,7 +80,7 @@ class Tape {
inline void set_is_running(bool is_running) { _is_running = is_running; }
inline void set_is_enabled(bool is_enabled) { _is_enabled = is_enabled; }
inline void set_is_in_input_mode(bool is_in_input_mode) {}
inline void set_is_in_input_mode(bool is_in_input_mode);
private:
inline void push_tape_bit(uint16_t bit);
@ -94,11 +94,13 @@ class Tape {
bool _is_running;
bool _is_enabled;
bool _is_in_input_mode;
int _bits_since_start;
inline void evaluate_interrupts();
int _bits_since_start, _output_bits_remaining;
uint16_t _data_register;
uint8_t _interrupt_status;
uint8_t _interrupt_status, _last_posted_interrupt_status;
Delegate *_delegate;
enum {