mirror of
https://github.com/TomHarte/CLK.git
synced 2025-02-03 22:33:29 +00:00
This is intended to be enough to start producing something of an output. But something's obviously still broken.
This commit is contained in:
parent
716bb3281b
commit
7341f5c341
@ -12,9 +12,17 @@
|
||||
|
||||
using namespace Electron;
|
||||
|
||||
Machine::Machine()
|
||||
static const int cycles_per_line = 128;
|
||||
static const int cycles_per_frame = 312*cycles_per_line;
|
||||
static const int crt_cycles_multiplier = 8;
|
||||
static const int crt_cycles_per_line = crt_cycles_multiplier * cycles_per_line;
|
||||
|
||||
Machine::Machine() :
|
||||
_interruptControl(0),
|
||||
_frameCycles(0),
|
||||
_outputPosition(0)
|
||||
{
|
||||
_crt = new Outputs::CRT(128, 312, 1, 1);
|
||||
_crt = new Outputs::CRT(crt_cycles_per_line, 312, 1, 1);
|
||||
_interruptStatus = 0x02;
|
||||
setup6502();
|
||||
}
|
||||
@ -25,6 +33,8 @@ Machine::~Machine()
|
||||
|
||||
unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value)
|
||||
{
|
||||
unsigned int cycles = 1;
|
||||
|
||||
if(address < 32768)
|
||||
{
|
||||
if(isReadOperation(operation))
|
||||
@ -34,9 +44,15 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
|
||||
else
|
||||
{
|
||||
_ram[address] = *value;
|
||||
|
||||
// TODO: range check on address; a lot of the time the machine will be running code outside of
|
||||
// the screen area, meaning that no update is required.
|
||||
// if (address
|
||||
update_display();
|
||||
}
|
||||
|
||||
// TODO: RAM timing
|
||||
// TODO: RAM timing for Modes 0–3
|
||||
cycles += (_frameCycles&1)^1;
|
||||
}
|
||||
else
|
||||
{
|
||||
@ -44,7 +60,7 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
|
||||
{
|
||||
if((address & 0xff00) == 0xfe00)
|
||||
{
|
||||
printf("%c: %02x: ", isReadOperation(operation) ? 'r' : 'w', *value);
|
||||
// printf("%c: %02x: ", isReadOperation(operation) ? 'r' : 'w', *value);
|
||||
|
||||
switch(address&0xf)
|
||||
{
|
||||
@ -57,18 +73,16 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
|
||||
else
|
||||
{
|
||||
_interruptControl = *value;
|
||||
evaluate_interrupts();
|
||||
}
|
||||
printf("Interrupt status or control\n");
|
||||
break;
|
||||
case 0x1:
|
||||
break;
|
||||
case 0x2:
|
||||
_screenStartAddress = (_screenStartAddress & 0xff00) | ((*value) & 0xe0);
|
||||
printf("Screen start address low, now %04x\n", _screenStartAddress);
|
||||
_startScreenAddress = (_startScreenAddress & 0xff00) | ((*value) & 0xe0);
|
||||
break;
|
||||
case 0x3:
|
||||
_screenStartAddress = (_screenStartAddress & 0x00ff) | (uint16_t)(((*value) & 0x3f) << 8);
|
||||
printf("Screen start address high, now %04x\n", _screenStartAddress);
|
||||
_startScreenAddress = (_startScreenAddress & 0x00ff) | (uint16_t)(((*value) & 0x3f) << 8);
|
||||
break;
|
||||
case 0x4:
|
||||
printf("Cassette\n");
|
||||
@ -81,7 +95,13 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
|
||||
{
|
||||
_activeRom = (Electron::ROMSlot)nextROM;
|
||||
}
|
||||
printf("Interrupt clear and paging\n");
|
||||
|
||||
if( (*value)&0x10 ) _interruptStatus &= ~InterruptDisplayEnd;
|
||||
if( (*value)&0x20 ) _interruptStatus &= InterruptRealTimeClock;
|
||||
if( (*value)&0x40 ) _interruptStatus &= InterruptHighToneDetect;
|
||||
evaluate_interrupts();
|
||||
|
||||
// TODO: NMI (?)
|
||||
}
|
||||
break;
|
||||
case 0x6:
|
||||
@ -91,7 +111,8 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
|
||||
printf("Misc. control\n");
|
||||
break;
|
||||
default:
|
||||
printf("Palette\n");
|
||||
update_display();
|
||||
// printf("Palette\n");
|
||||
break;
|
||||
}
|
||||
}
|
||||
@ -121,7 +142,16 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
|
||||
}
|
||||
}
|
||||
|
||||
return 1;
|
||||
_frameCycles += cycles;
|
||||
if(_frameCycles == cycles_per_frame)
|
||||
{
|
||||
update_display();
|
||||
_frameCycles = 0;
|
||||
}
|
||||
if(_frameCycles == 128*128) signal_interrupt(InterruptRealTimeClock);
|
||||
if(_frameCycles == 284*128) signal_interrupt(InterruptDisplayEnd);
|
||||
|
||||
return cycles;
|
||||
}
|
||||
|
||||
void Machine::set_rom(ROMSlot slot, size_t length, const uint8_t *data)
|
||||
@ -136,3 +166,81 @@ void Machine::set_rom(ROMSlot slot, size_t length, const uint8_t *data)
|
||||
|
||||
memcpy(target, data, std::min((size_t)16384, length));
|
||||
}
|
||||
|
||||
inline void Machine::signal_interrupt(Electron::Interrupt interrupt)
|
||||
{
|
||||
_interruptStatus |= (interrupt << 2);
|
||||
evaluate_interrupts();
|
||||
}
|
||||
|
||||
inline void Machine::evaluate_interrupts()
|
||||
{
|
||||
if(_interruptStatus & _interruptControl)
|
||||
{
|
||||
_interruptStatus |= 1;
|
||||
}
|
||||
set_irq_line(_interruptStatus & 1);
|
||||
}
|
||||
|
||||
inline void Machine::update_display()
|
||||
{
|
||||
const int end_of_hsync = 3 * cycles_per_line;
|
||||
|
||||
if(_frameCycles >= end_of_hsync)
|
||||
{
|
||||
// assert sync for the first three lines of the display
|
||||
if(_outputPosition < end_of_hsync)
|
||||
{
|
||||
_crt->output_sync(end_of_hsync * crt_cycles_multiplier);
|
||||
_outputPosition = end_of_hsync;
|
||||
}
|
||||
|
||||
while(_outputPosition < _frameCycles)
|
||||
{
|
||||
const int current_line = _outputPosition >> 7;
|
||||
const int line_position = _outputPosition & 127;
|
||||
|
||||
// all lines then start with 9 cycles of sync
|
||||
if(!line_position)
|
||||
{
|
||||
_crt->output_sync(9 * crt_cycles_multiplier);
|
||||
_outputPosition += 9;
|
||||
}
|
||||
else
|
||||
{
|
||||
// on lines prior to 28 or after or equal to 284, or on a line that is equal to 8 or 9 modulo 10 in a line-spaced mode,
|
||||
// the line is then definitely blank.
|
||||
if(current_line < 28 || current_line >= 284)
|
||||
{
|
||||
if(line_position == 9)
|
||||
{
|
||||
_crt->output_blank(119 * crt_cycles_multiplier);
|
||||
_outputPosition += 119;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
// there are then 15 cycles of blank, 80 cycles of pixels, and 24 further cycles of blank
|
||||
if(line_position == 9)
|
||||
{
|
||||
_crt->output_blank(15 * crt_cycles_multiplier);
|
||||
_outputPosition += 15;
|
||||
_crt->output_data(80 * crt_cycles_multiplier);
|
||||
}
|
||||
|
||||
if(line_position >= 24 && line_position < 104)
|
||||
{
|
||||
// TODO: actually output some pixels, why not?
|
||||
_outputPosition++;
|
||||
}
|
||||
|
||||
if(line_position == 104)
|
||||
{
|
||||
_crt->output_blank(24 * crt_cycles_multiplier);
|
||||
_outputPosition += 24;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
@ -29,6 +29,14 @@ enum ROMSlot: uint8_t {
|
||||
ROMSlotOS
|
||||
};
|
||||
|
||||
enum Interrupt: uint8_t {
|
||||
InterruptRealTimeClock = 0x01,
|
||||
InterruptDisplayEnd = 0x02,
|
||||
InterruptTransmitDataEmpty = 0x04,
|
||||
InterruptReceiveDataFull = 0x08,
|
||||
InterruptHighToneDetect = 0x10
|
||||
};
|
||||
|
||||
class Machine: public CPU6502::Processor<Machine> {
|
||||
|
||||
public:
|
||||
@ -45,10 +53,16 @@ class Machine: public CPU6502::Processor<Machine> {
|
||||
private:
|
||||
uint8_t _os[16384], _basic[16384], _ram[32768];
|
||||
uint8_t _interruptStatus, _interruptControl;
|
||||
uint16_t _screenStartAddress;
|
||||
ROMSlot _activeRom;
|
||||
|
||||
Outputs::CRT *_crt;
|
||||
|
||||
int _frameCycles, _outputPosition;
|
||||
uint16_t _startScreenAddress, _currentScreenAddress;
|
||||
|
||||
inline void update_display();
|
||||
inline void signal_interrupt(Interrupt interrupt);
|
||||
inline void evaluate_interrupts();
|
||||
};
|
||||
|
||||
}
|
||||
|
@ -981,6 +981,16 @@ template <class T> class Processor {
|
||||
_reset_line_is_enabled = active;
|
||||
}
|
||||
|
||||
void set_irq_line(bool active)
|
||||
{
|
||||
// TODO
|
||||
}
|
||||
|
||||
void set_nmi_line(bool active)
|
||||
{
|
||||
// TODO
|
||||
}
|
||||
|
||||
bool is_jammed()
|
||||
{
|
||||
return _is_jammed;
|
||||
|
Loading…
x
Reference in New Issue
Block a user