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... and that's a flashing cursor. Keyboard input next!

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This commit is contained in:
Thomas Harte 2016-06-09 22:37:59 -04:00
parent 30b7db3979
commit f3b1d7de82
4 changed files with 91 additions and 9 deletions
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80
Components/6522/6522.hpp
View File

@ -14,8 +14,29 @@
namespace MOS {
template <class T> class MOS6522 {
class MOS6522Delegate {
public:
virtual void mos6522_did_change_interrupt_status(void *mos6522) = 0;
};
template <class T> class MOS6522 {
private:
enum InterruptFlag: uint8_t {
CA2ActiveEdge = 1 << 0,
CA1ActiveEdge = 1 << 1,
ShiftRegister = 1 << 2,
CB2ActiveEdge = 1 << 3,
CB1ActiveEdge = 1 << 4,
Timer2 = 1 << 5,
Timer1 = 1 << 6,
};
public:
void set_delegate(MOS6522Delegate *delegate)
{
_delegate = delegate;
}
MOS6522() :
_data_direction{0, 0},
_timer_is_running{false, false}
@ -31,23 +52,31 @@ template <class T> class MOS6522 {
case 0x06: case 0x04: _interval_timer_latch[0] = (_interval_timer_latch[0]&0xff00) | value; break;
case 0x05: case 0x07:
_interval_timer_latch[0] = (_interval_timer_latch[0]&0x00ff) | (uint16_t)(value << 8);
// TODO: clear interrupt flag
_interrupt_flags &= ~InterruptFlag::Timer1;
if(address == 0x05)
{
_interval_timer[0] = _interval_timer_latch[0];
_timer_is_running[0] = true;
}
reevaluate_interrupts();
break;
// Timer 2
case 0x08: _interval_timer_latch[1] = value; break;
case 0x09:
// TODO: clear interrupt flag
_interrupt_flags &= ~InterruptFlag::Timer2;
_interval_timer[1] = _interval_timer_latch[1] | (uint16_t)(value << 8);
_timer_is_running[1] = true;
reevaluate_interrupts();
break;
case 0x11: _auxiliary_control_register = value; break;
case 11: _auxiliary_control_register = value; break;
case 13:
if(!(value&0x80)) value = ~value;
_interrupt_mask = value;
break;
case 14:
break;
}
}
@ -59,11 +88,16 @@ template <class T> class MOS6522 {
{
// Timer 1
case 0x04:
// TODO: clear interrupt flag
_interrupt_flags &= ~InterruptFlag::Timer1;
reevaluate_interrupts();
return _interval_timer[0] & 0x00ff;
case 0x05: return _interval_timer[0] >> 8;
case 0x06: return _interval_timer_latch[0] & 0x00ff;
case 0x07: return _interval_timer_latch[0] >> 8;
case 11: return _auxiliary_control_register;
case 13: return _interrupt_flags;
case 14: return _interrupt_mask;
}
return 0xff;
@ -73,14 +107,48 @@ template <class T> class MOS6522 {
{
_interval_timer[0] -= number_of_cycles;
_interval_timer[1] -= number_of_cycles;
// TODO: interrupts, potentially reload of the first timer, other status effects
if(!_interval_timer[1] && _timer_is_running[1])
{
_timer_is_running[1] = false;
_interrupt_flags |= InterruptFlag::Timer2;
reevaluate_interrupts();
}
if(!_interval_timer[0] && _timer_is_running[0])
{
_interrupt_flags |= InterruptFlag::Timer1;
reevaluate_interrupts();
// TODO: reload shouldn't occur for a further 1.5 cycles
if(_auxiliary_control_register&0x40)
{
_interval_timer[0] = _interval_timer_latch[0];
}
else
_timer_is_running[0] = false;
}
// TODO: lots of other status effects
}
bool get_interrupt_line()
{
uint8_t interrupt_status = _interrupt_flags & (~_interrupt_mask) & 0x7f;
return !!interrupt_status;
}
private:
inline void reevaluate_interrupts()
{
if(_delegate) _delegate->mos6522_did_change_interrupt_status(this);
}
MOS6522Delegate *_delegate;
uint16_t _interval_timer[2], _interval_timer_latch[2];
uint8_t _shift_register;
uint8_t _input_latch[2];
uint8_t _data_direction[2];
uint8_t _interrupt_flags, _interrupt_mask;
bool _timer_is_running[2];

4
Components/6560/6560.cpp
View File

@ -120,8 +120,8 @@ uint8_t MOS6560::get_register(int address)
switch(address)
{
default: return _registers[address];
case 0x03: return ((_vertical_counter >> 1) & 0x80) | (_registers[3] & 0x7f);
case 0x04: return _vertical_counter & 0xff;
case 0x03: return (uint8_t)(_vertical_counter << 7) | (_registers[3] & 0x7f);
case 0x04: return (_vertical_counter >> 1) & 0xff;
}
}

11
Machines/Vic-20/Vic20.cpp
View File

@ -16,6 +16,8 @@ Machine::Machine() :
_userPortVIA(new UserPortVIA()),
_keyboardVIA(new KeyboardVIA())
{
_userPortVIA->set_delegate(this);
_keyboardVIA->set_delegate(this);
set_reset_line(true);
}
@ -68,6 +70,15 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
return 1;
}
#pragma mark - 6522 delegate
void Machine::mos6522_did_change_interrupt_status(void *mos6522)
{
bool irq = _userPortVIA->get_interrupt_line() || _keyboardVIA->get_interrupt_line();
printf("IRQ: %s\n", irq ? "e" : "-");
set_irq_line(irq);
}
#pragma mark - Setup
void Machine::setup_output(float aspect_ratio)

5
Machines/Vic-20/Vic20.hpp
View File

@ -28,7 +28,7 @@ class UserPortVIA: public MOS::MOS6522<UserPortVIA> {
class KeyboardVIA: public MOS::MOS6522<KeyboardVIA> {
};
class Machine: public CPU6502::Processor<Machine>, public CRTMachine::Machine {
class Machine: public CPU6502::Processor<Machine>, public CRTMachine::Machine, public MOS::MOS6522Delegate {
public:
Machine();
@ -46,6 +46,9 @@ class Machine: public CPU6502::Processor<Machine>, public CRTMachine::Machine {
virtual Outputs::Speaker *get_speaker() { return nullptr; } // TODO
virtual void run_for_cycles(int number_of_cycles) { CPU6502::Processor<Machine>::run_for_cycles(number_of_cycles); }
// to satisfy MOS::MOS6522::Delegate
virtual void mos6522_did_change_interrupt_status(void *mos6522);
private:
uint8_t _characterROM[0x1000];
uint8_t _basicROM[0x2000];