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CLK/Machines/Electron/Electron.cpp

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//
// Electron.cpp
// Clock Signal
//
// Created by Thomas Harte on 03/01/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#include "Electron.hpp"
#include "TapeUEF.hpp"
#include <algorithm>
using namespace Electron;
static const unsigned int cycles_per_line = 128;
static const unsigned int cycles_per_frame = 312*cycles_per_line + 64;
static const unsigned int crt_cycles_multiplier = 8;
static const unsigned int crt_cycles_per_line = crt_cycles_multiplier * cycles_per_line;
static const int first_graphics_line = 38;
static const int first_graphics_cycle = 33;
static const int last_graphics_cycle = 80 + first_graphics_cycle;
Machine::Machine() :
_interrupt_control(0),
_interrupt_status(Interrupt::PowerOnReset),
_fieldCycles(0),
_displayOutputPosition(0),
_audioOutputPosition(0),
_audioOutputPositionError(0),
_currentOutputLine(0),
_is_odd_field(false),
_crt(std::unique_ptr<Outputs::CRT>(new Outputs::CRT(crt_cycles_per_line, Outputs::CRT::DisplayType::PAL50, 1, 1)))
{
_crt->set_rgb_sampling_function(
"vec3 rgb_sample(vec2 coordinate)"
"{"
"float texValue = texture(texID, coordinate).r;"
"return vec3(step(4.0/256.0, mod(texValue, 8.0/256.0)), step(2.0/256.0, mod(texValue, 4.0/256.0)), step(1.0/256.0, mod(texValue, 2.0/256.0)));"
"}");
// _crt->set_visible_area(Outputs::Rect(0.23108f, 0.0f, 0.8125f, 0.98f)); //1875
memset(_key_states, 0, sizeof(_key_states));
memset(_palette, 0xf, sizeof(_palette));
for(int c = 0; c < 16; c++)
memset(_roms[c], 0xff, 16384);
_speaker.set_input_rate(125000);
_tape.set_delegate(this);
}
unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value)
{
unsigned int cycles = 1;
if(address < 0x8000)
{
if(isReadOperation(operation))
{
*value = _ram[address];
}
else
{
// If we're still before the display will start to be painted, or the address is
// less than both the current line address and 0x3000, (the minimum screen mode
// base address) then there's no way this write can affect the current frame. Sp
// no need to flush the display. Otherwise, output up until now so that any
// write doesn't have retroactive effect on the video output.
if(!(
(_fieldCycles < first_graphics_line * cycles_per_line) ||
(address < _startLineAddress && address < 0x3000)
))
update_display();
_ram[address] = *value;
}
// for the entire frame, RAM is accessible only on odd cycles; in modes below 4
// it's also accessible only outside of the pixel regions
cycles += (_fieldCycles&1)^1;
if(_screen_mode < 4)
{
const int current_line = _fieldCycles >> 7;
const int line_position = _fieldCycles & 127;
if(current_line >= first_graphics_line && current_line < first_graphics_line+256 && line_position >= first_graphics_cycle && line_position < first_graphics_cycle + 80)
cycles = (unsigned int)(80 + first_graphics_cycle - line_position);
}
}
else
{
if(address >= 0xc000)
{
if((address & 0xff00) == 0xfe00)
{
cycles += (_fieldCycles&1)^1;
// printf("%c: %02x: ", isReadOperation(operation) ? 'r' : 'w', *value);
switch(address&0xf)
{
case 0x0:
if(isReadOperation(operation))
{
*value = _interrupt_status;
_interrupt_status &= ~0x02;
}
else
{
_interrupt_control = *value;
evaluate_interrupts();
}
break;
case 0x1:
break;
case 0x2:
printf("%02x to [2] mutates %04x ", *value, _startScreenAddress);
_startScreenAddress = (_startScreenAddress & 0xfe00) | (uint16_t)(((*value) & 0xe0) << 1);
printf("into %04x\n", _startScreenAddress);
break;
case 0x3:
printf("%02x to [3] mutates %04x ", *value, _startScreenAddress);
_startScreenAddress = (_startScreenAddress & 0x01ff) | (uint16_t)(((*value) & 0x3f) << 9);
printf("into %04x\n", _startScreenAddress);
break;
case 0x4:
if(isReadOperation(operation))
{
*value = _tape.get_data_register();
_tape.clear_interrupts(Interrupt::ReceiveDataFull);
}
else
{
_tape.set_data_register(*value);
_tape.clear_interrupts(Interrupt::TransmitDataEmpty);
}
break;
case 0x5:
if(!isReadOperation(operation))
{
const uint8_t interruptDisable = (*value)&0xf0;
if( interruptDisable )
{
if( interruptDisable&0x10 ) _interrupt_status &= ~Interrupt::DisplayEnd;
if( interruptDisable&0x20 ) _interrupt_status &= ~Interrupt::RealTimeClock;
if( interruptDisable&0x40 ) _interrupt_status &= ~Interrupt::HighToneDetect;
evaluate_interrupts();
// TODO: NMI (?)
}
// else
{
uint8_t nextROM = (*value)&0xf;
// if(nextROM&0x08)
// {
// _activeRom = (Electron::ROMSlot)(nextROM&0x0e);
// printf("%d -> Paged %d\n", nextROM, _activeRom);
// }
if(((_active_rom&12) != 8) || (nextROM&8))
{
_active_rom = (Electron::ROMSlot)nextROM;
}
// else
// {
// printf("Ignored!");
// }
// printf("%d -> Paged %d\n", nextROM, _activeRom);
}
}
break;
case 0x6:
if(!isReadOperation(operation))
{
update_audio();
_speaker.set_divider(*value);
_tape.set_counter(*value);
}
break;
case 0x7:
if(!isReadOperation(operation))
{
// update screen mode
uint8_t new_screen_mode = ((*value) >> 3)&7;
if(new_screen_mode == 7) new_screen_mode = 4;
if(new_screen_mode != _screen_mode)
{
update_display();
_screen_mode = new_screen_mode;
switch(_screen_mode)
{
case 0: case 1: case 2: _screenModeBaseAddress = 0x3000; break;
case 3: _screenModeBaseAddress = 0x4000; break;
case 4: case 5: _screenModeBaseAddress = 0x5800; break;
case 6: _screenModeBaseAddress = 0x6000; break;
}
}
// update speaker mode
bool new_speaker_is_enabled = (*value & 6) == 2;
if(new_speaker_is_enabled != _speaker.get_is_enabled())
{
update_audio();
_speaker.set_is_enabled(new_speaker_is_enabled);
_tape.set_is_enabled(!new_speaker_is_enabled);
}
_tape.set_is_running(((*value)&0x40) ? true : false);
_tape.set_is_in_input_mode(((*value)&0x04) ? false : true);
// TODO: caps lock LED
}
break;
default:
{
if(!isReadOperation(operation))
{
update_display();
static const int registers[4][4] = {
{10, 8, 2, 0},
{14, 12, 6, 4},
{15, 13, 7, 5},
{11, 9, 3, 1},
};
const int index = (address >> 1)&3;
const uint8_t colour = ~(*value);
if(address&1)
{
_palette[registers[index][0]] = (_palette[registers[index][0]]&3) | ((colour >> 1)&4);
_palette[registers[index][1]] = (_palette[registers[index][1]]&3) | ((colour >> 0)&4);
_palette[registers[index][2]] = (_palette[registers[index][2]]&3) | ((colour << 1)&4);
_palette[registers[index][3]] = (_palette[registers[index][3]]&3) | ((colour << 2)&4);
_palette[registers[index][2]] = (_palette[registers[index][2]]&5) | ((colour >> 4)&2);
_palette[registers[index][3]] = (_palette[registers[index][3]]&5) | ((colour >> 3)&2);
}
else
{
_palette[registers[index][0]] = (_palette[registers[index][0]]&6) | ((colour >> 7)&1);
_palette[registers[index][1]] = (_palette[registers[index][1]]&6) | ((colour >> 6)&1);
_palette[registers[index][2]] = (_palette[registers[index][2]]&6) | ((colour >> 5)&1);
_palette[registers[index][3]] = (_palette[registers[index][3]]&6) | ((colour >> 4)&1);
_palette[registers[index][0]] = (_palette[registers[index][0]]&5) | ((colour >> 2)&2);
_palette[registers[index][1]] = (_palette[registers[index][1]]&5) | ((colour >> 1)&2);
}
}
}
break;
}
}
else
{
if(isReadOperation(operation))
*value = _os[address & 16383];
}
}
else
{
if(isReadOperation(operation))
{
switch(_active_rom)
{
case ROMSlotKeyboard:
case ROMSlotKeyboard+1:
*value = 0xf0;
for(int address_line = 0; address_line < 14; address_line++)
{
if(!(address&(1 << address_line))) *value |= _key_states[address_line];
}
break;
default:
*value = _roms[_active_rom][address & 16383];
break;
}
}
}
}
// if(operation == CPU6502::BusOperation::ReadOpcode)
// {
// printf("%04x: %02x (%d)\n", address, *value, _fieldCycles);
// }
unsigned int line_position = (unsigned int)get_line_output_position(_fieldCycles);
const unsigned int real_time_clock_interrupt_time = (first_graphics_line + 99)*128 + first_graphics_cycle + 80;
const unsigned int display_end_interrupt_time = (first_graphics_line + 255)*128 + first_graphics_cycle + 80;
if(line_position < real_time_clock_interrupt_time && line_position + cycles >= real_time_clock_interrupt_time)
{
update_audio();
signal_interrupt(Interrupt::RealTimeClock);
}
else if(line_position < display_end_interrupt_time && line_position + cycles >= display_end_interrupt_time)
{
update_audio();
signal_interrupt(Interrupt::DisplayEnd);
}
_fieldCycles += cycles;
switch(_fieldCycles)
{
case 64*128:
case 196*128:
update_audio();
break;
case cycles_per_frame:
update_display();
update_audio();
_fieldCycles = 0;
_displayOutputPosition = 0;
_audioOutputPosition = 0;
_currentOutputLine = 0;
break;
}
_tape.run_for_cycles(cycles);
return cycles;
}
void Machine::update_output()
{
update_display();
update_audio();
}
void Machine::set_tape(std::shared_ptr<Storage::Tape> tape)
{
_tape.set_tape(tape);
}
void Machine::set_rom(ROMSlot slot, size_t length, const uint8_t *data)
{
uint8_t *target = nullptr;
switch(slot)
{
case ROMSlotOS: target = _os; break;
default: target = _roms[slot]; break;
}
memcpy(target, data, std::min((size_t)16384, length));
}
inline void Machine::signal_interrupt(Electron::Interrupt interrupt)
{
_interrupt_status |= interrupt;
evaluate_interrupts();
}
void Machine::tape_did_change_interrupt_status(Tape *tape)
{
_interrupt_status = (_interrupt_status & ~(Interrupt::TransmitDataEmpty | Interrupt::ReceiveDataFull | Interrupt::HighToneDetect)) | _tape.get_interrupt_status();
evaluate_interrupts();
}
inline void Machine::evaluate_interrupts()
{
if(_interrupt_status & _interrupt_control)
{
_interrupt_status |= 1;
}
else
{
_interrupt_status &= ~1;
}
set_irq_line(_interrupt_status & 1);
}
inline void Machine::update_audio()
{
int difference = _fieldCycles - _audioOutputPosition;
_audioOutputPosition = _fieldCycles;
_speaker.run_for_cycles((_audioOutputPositionError + difference) >> 4);
_audioOutputPositionError = (_audioOutputPositionError + difference)&15;
}
inline int Machine::get_line_output_position(int field_address)
{
return field_address + (_is_odd_field ? 64 : 0);
}
inline void Machine::reset_pixel_output()
{
display_x = 0;
display_y = 0;
_currentScreenAddress = _startLineAddress = _startScreenAddress;
_currentOutputLine = 0;
}
inline void Machine::output_pixels(int start_x, int number_of_pixels)
{
if(number_of_pixels)
{
unsigned int newDivider = 0;
switch(_screen_mode)
{
case 0: case 3: newDivider = 1; break;
case 1: case 4: case 6: newDivider = 2; break;
case 2: case 5: newDivider = 4; break;
}
bool is40Column = (_screen_mode > 3);
if(!_writePointer || newDivider != _currentOutputDivider || _isOutputting40Columns != is40Column)
{
end_pixel_output();
_currentOutputDivider = newDivider;
_isOutputting40Columns = is40Column;
_crt->allocate_write_area(640 / newDivider);
_currentLine = _writePointer = _crt->get_write_target_for_buffer(0);
}
if(is40Column)
{
number_of_pixels = ((start_x + number_of_pixels) >> 1) - (start_x >> 1);
}
#define GetNextPixels() \
if(_currentScreenAddress&32768)\
{\
_currentScreenAddress = (_screenModeBaseAddress + _currentScreenAddress)&32767;\
}\
uint8_t pixels = _ram[_currentScreenAddress];\
_currentScreenAddress = _currentScreenAddress+8
switch(_screen_mode)
{
default:
case 0: case 3: case 4: case 6:
while(number_of_pixels--)
{
GetNextPixels();
_writePointer[0] = _palette[(pixels&0x80) >> 4];
_writePointer[1] = _palette[(pixels&0x40) >> 3];
_writePointer[2] = _palette[(pixels&0x20) >> 2];
_writePointer[3] = _palette[(pixels&0x10) >> 1];
_writePointer[4] = _palette[(pixels&0x08) >> 0];
_writePointer[5] = _palette[(pixels&0x04) << 1];
_writePointer[6] = _palette[(pixels&0x02) << 2];
_writePointer[7] = _palette[(pixels&0x01) << 3];
_writePointer += 8;
}
break;
case 1: case 5:
while(number_of_pixels--)
{
GetNextPixels();
_writePointer[0] = _palette[((pixels&0x80) >> 4) | ((pixels&0x08) >> 2)];
_writePointer[1] = _palette[((pixels&0x40) >> 3) | ((pixels&0x04) >> 1)];
_writePointer[2] = _palette[((pixels&0x20) >> 2) | ((pixels&0x02) >> 0)];
_writePointer[3] = _palette[((pixels&0x10) >> 1) | ((pixels&0x01) << 1)];
_writePointer += 4;
}
break;
case 2:
while(number_of_pixels--)
{
GetNextPixels();
_writePointer[0] = _palette[((pixels&0x80) >> 4) | ((pixels&0x20) >> 3) | ((pixels&0x08) >> 2) | ((pixels&0x02) >> 1)];
_writePointer[1] = _palette[((pixels&0x40) >> 3) | ((pixels&0x10) >> 2) | ((pixels&0x04) >> 1) | ((pixels&0x01) >> 0)];
_writePointer += 2;
}
break;
}
}
#undef GetNextPixels
}
inline void Machine::end_pixel_output()
{
if(_currentLine != nullptr)
{
_crt->output_data((unsigned int)((_writePointer - _currentLine) * _currentOutputDivider), _currentOutputDivider);
_writePointer = _currentLine = nullptr;
}
}
inline void Machine::update_pixels_to_position(int x, int y)
{
static unsigned int end;
while((display_x < x) || (display_y < y))
{
if(display_x < first_graphics_cycle)
{
display_x++;
if(display_x == first_graphics_cycle)
{
_crt->output_sync(9 * crt_cycles_multiplier);
_crt->output_blank((first_graphics_cycle - 9) * crt_cycles_multiplier);
end = _crt->get_field_cycle();
_currentScreenAddress = _startLineAddress;
}
continue;
}
if(display_x < last_graphics_cycle)
{
int cycles_to_output = (display_y < y) ? last_graphics_cycle - display_x : std::min(last_graphics_cycle - display_x, x - display_x);
output_pixels(display_x, cycles_to_output);
display_x += cycles_to_output;
if(display_x == last_graphics_cycle)
{
end_pixel_output();
// if(_crt->get_field_cycle() - end != 640)
// {
// printf("!!!\n");
// }
}
continue;
}
display_x++;
if(display_x == 128)
{
_crt->output_blank((128 - 80 - first_graphics_cycle) * crt_cycles_multiplier);
display_x = 0;
display_y++;
_startLineAddress++;
_currentOutputLine++;
if(_currentOutputLine == 8)
{
_currentOutputLine = 0;
_startLineAddress = _currentScreenAddress - 7;
}
}
}
/* while(_displayOutputPosition < end_of_graphics && _displayOutputPosition)
{
int displayOffset = _displayOutputPosition - end_of_graphics;
int cyclesRemaining = _fieldCycles - _displayOutputPosition;
// int current_line = displayOffset >> 7;
int current_pixel = displayOffset & 127;
if(current_pixel < 9)
{
if(cyclesRemaining > 9)
{
_crt->output_sync(9 * crt_cycles_multiplier);
cyclesRemaining -= 9;
_displayOutputPosition += 9;
}
else return;
}
int line_remainder = std::min(119, cyclesRemaining);
_crt->output_blank((unsigned int)line_remainder * crt_cycles_multiplier);
_displayOutputPosition += line_remainder;
current_pixel += line_remainder;
if(current_pixel < 128) return;
}*/
}
inline void Machine::update_display()
{
/*
Odd field:
|--S--|
|--S--|
|-S-B-|
|--B--|
|--P--|
|--B--|
(2.5 lines of sync; half a line of blank; full blanks; pixels; full blanks; half blank)
Even field:
|-B-S-|
|--S--|
|--S--|
|--B--|
|--P--|
|--B--|
(2.5 lines of sync; full blanks; pixels; full blanks)
So:
Top:
if even then half a line of blank
2.5 lines of sync
if odd then half a line of blank
full blanks
Pixels
Bottom:
full blanks
*/
const int end_of_top = (first_graphics_line * cycles_per_line) + (_is_odd_field ? 64 : 0);
const int end_of_graphics = ((first_graphics_line + 256) * cycles_per_line) + (_is_odd_field ? 64 : 0);
// does the top region need to be output?
if(_displayOutputPosition < end_of_top && _fieldCycles >= end_of_top)
{
// printf("[1] %d / %d\n", _crt->get_field_cycle() >> 10, (_crt->get_field_cycle() >> 3)&127);
if(!_is_odd_field)
{
_crt->output_sync(9 * crt_cycles_multiplier);
_crt->output_blank(55 * crt_cycles_multiplier);
}
_crt->output_sync(320 * crt_cycles_multiplier);
if(_is_odd_field) _crt->output_blank(64 * crt_cycles_multiplier);
for(int y = 3; y < first_graphics_line; y++)
{
_crt->output_sync(9 * crt_cycles_multiplier);
_crt->output_blank(119 * crt_cycles_multiplier);
}
// printf("[2] %d / %d\n", _crt->get_field_cycle() >> 10, (_crt->get_field_cycle() >> 3)&127);
_displayOutputPosition = end_of_top;
reset_pixel_output();
}
// is this the pixel region?
if(_displayOutputPosition >= end_of_top && _displayOutputPosition < end_of_graphics)
{
int final_position = std::min(_fieldCycles, end_of_top + 256 * 128) - end_of_top;
int final_line = final_position >> 7;
int final_pixel = final_position & 127;
update_pixels_to_position(final_pixel, final_line);
_displayOutputPosition = final_position + end_of_top;
}
// is this the bottom region?
if(_displayOutputPosition >= end_of_graphics && _displayOutputPosition < cycles_per_frame)
{
// printf("[3] %d / %d\n", _crt->get_field_cycle() >> 10, (_crt->get_field_cycle() >> 3)&127);
for(int y = first_graphics_line+256; y < 312; y++)
{
_crt->output_sync(9 * crt_cycles_multiplier);
_crt->output_blank(119 * crt_cycles_multiplier);
}
_displayOutputPosition = cycles_per_frame;
// printf("[4] %d / %d\n", _crt->get_field_cycle() >> 10, (_crt->get_field_cycle() >> 3)&127);
_is_odd_field ^= true;
}
// no? Then let's do some pixels
/* if(_fieldCycles >= end_of_hsync)
{
// assert sync for the first three lines of the display, with a break at the end for horizontal alignment
if(_displayOutputPosition < end_of_hsync)
{
_crt->output_sync(9 * crt_cycles_multiplier);
_crt->output_blank(55 * crt_cycles_multiplier);
_crt->output_sync(320 * crt_cycles_multiplier);
_is_odd_field ^= true;
_displayOutputPosition = end_of_hsync;
}
while(_displayOutputPosition >= end_of_hsync && _displayOutputPosition < _fieldCycles)
{
const int cycles_left = _fieldCycles - _displayOutputPosition;
const int fieldOutputPosition = get_line_output_position(_displayOutputPosition);
const int current_line = fieldOutputPosition >> 7;
const int line_position = fieldOutputPosition & 127;
// all lines then start with 9 cycles of sync
if(line_position < 9)
{
int remaining_period = std::min(9 - line_position, cycles_left);
_displayOutputPosition += remaining_period;
if(line_position + remaining_period == 9)
{
_crt->output_sync(9 * crt_cycles_multiplier);
}
}
else
{
bool isBlankLine =
(current_line < first_graphics_line) ||
(((_screen_mode == 3) || (_screen_mode == 6)) ?
((current_line >= first_graphics_line+248) || (((current_line - first_graphics_line)%10) > 7)) :
((current_line >= first_graphics_line+256)));
bool isBlankPeriod =
(line_position < first_graphics_cycle) || (line_position >= 80+first_graphics_cycle);
if(isBlankLine || isBlankPeriod)
{
if(_currentLine)
{
_crt->output_data((unsigned int)((_writePointer - _currentLine) * _currentOutputDivider * crt_cycles_multiplier), _currentOutputDivider);
_currentLine = _writePointer = nullptr;
}
int target = (isBlankLine || (line_position > first_graphics_cycle)) ? 128 : first_graphics_cycle;
int remaining_period = std::min(target - line_position, cycles_left);
_crt->output_blank((unsigned int)remaining_period * crt_cycles_multiplier);
_displayOutputPosition += remaining_period;
if(line_position + remaining_period == 128)
{
_currentOutputLine++;
if(!(_currentOutputLine&7))
{
_startLineAddress += ((_screen_mode < 4) ? 80 : 40)*8 - 7;
}
else
_startLineAddress++;
}
}
else
{
if(line_position == first_graphics_cycle)
{
if(current_line == first_graphics_line) _startLineAddress = _startScreenAddress;
_currentScreenAddress = _startLineAddress;
}
// determine the pixel clock
unsigned int newDivider = 0;
switch(_screen_mode)
{
case 0: case 3: newDivider = 1; break;
case 1: case 4: case 6: newDivider = 2; break;
case 2: case 5: newDivider = 4; break;
}
// if the clock has changed or we don't yet have a write pointer, get one
if((newDivider != _currentOutputDivider) || !_currentLine)
{
if(_currentLine)
{
_crt->output_data((unsigned int)((_writePointer - _currentLine) * _currentOutputDivider * crt_cycles_multiplier), _currentOutputDivider);
}
_currentOutputDivider = newDivider;
_crt->allocate_write_area((size_t)((80 + first_graphics_cycle - (unsigned int)line_position) * crt_cycles_multiplier / _currentOutputDivider));
_currentLine = _writePointer = (uint8_t *)_crt->get_write_target_for_buffer(0);
}
// determine how many pixels to write
int pixels_to_output = std::min(80 + first_graphics_cycle - line_position, cycles_left);
_displayOutputPosition += pixels_to_output;
if(_screen_mode >= 4)
{
if(_displayOutputPosition&1) pixels_to_output++;
pixels_to_output >>= 1;
}
#define GetNextPixels() \
if(_currentScreenAddress&32768)\
{\
_currentScreenAddress = (_screenModeBaseAddress + _currentScreenAddress)&32767;\
}\
uint8_t pixels = _ram[_currentScreenAddress];\
_currentScreenAddress = _currentScreenAddress+8
if(pixels_to_output)
{
switch(_screen_mode)
{
default:
case 0: case 3: case 4: case 6:
while(pixels_to_output--)
{
GetNextPixels();
_writePointer[0] = _palette[(pixels&0x80) >> 4];
_writePointer[1] = _palette[(pixels&0x40) >> 3];
_writePointer[2] = _palette[(pixels&0x20) >> 2];
_writePointer[3] = _palette[(pixels&0x10) >> 1];
_writePointer[4] = _palette[(pixels&0x08) >> 0];
_writePointer[5] = _palette[(pixels&0x04) << 1];
_writePointer[6] = _palette[(pixels&0x02) << 2];
_writePointer[7] = _palette[(pixels&0x01) << 3];
_writePointer += 8;
}
break;
case 1:
case 5:
while(pixels_to_output--)
{
GetNextPixels();
_writePointer[0] = _palette[((pixels&0x80) >> 4) | ((pixels&0x08) >> 2)];
_writePointer[1] = _palette[((pixels&0x40) >> 3) | ((pixels&0x04) >> 1)];
_writePointer[2] = _palette[((pixels&0x20) >> 2) | ((pixels&0x02) >> 0)];
_writePointer[3] = _palette[((pixels&0x10) >> 1) | ((pixels&0x01) << 1)];
_writePointer += 4;
}
break;
case 2:
while(pixels_to_output--)
{
GetNextPixels();
_writePointer[0] = _palette[((pixels&0x80) >> 4) | ((pixels&0x20) >> 3) | ((pixels&0x08) >> 2) | ((pixels&0x02) >> 1)];
_writePointer[1] = _palette[((pixels&0x40) >> 3) | ((pixels&0x10) >> 2) | ((pixels&0x04) >> 1) | ((pixels&0x01) >> 0)];
_writePointer += 2;
}
break;
}
}
#undef GetNextPixels
}
}
}
}*/
}
void Machine::set_key_state(Key key, bool isPressed)
{
if(key == KeyBreak)
{
set_reset_line(isPressed);
}
else
{
if(isPressed)
_key_states[key >> 4] |= key&0xf;
else
_key_states[key >> 4] &= ~(key&0xf);
}
}
/*
Speaker
*/
void Speaker::get_samples(unsigned int number_of_samples, int16_t *target)
{
if(!_is_enabled)
{
*target = 0;
}
else
{
*target = _output_level;
}
skip_samples(number_of_samples);
}
void Speaker::skip_samples(unsigned int number_of_samples)
{
while(number_of_samples--)
{
_counter ++;
if(_counter > _divider)
{
_counter = 0;
_output_level ^= 8192;
}
}
}
void Speaker::set_divider(uint8_t divider)
{
_divider = divider;
}
void Speaker::set_is_enabled(bool is_enabled)
{
_is_enabled = is_enabled;
_counter = 0;
}
/*
Tape
*/
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)
{
_tape = tape;
get_next_tape_pulse();
}
inline void Tape::get_next_tape_pulse()
{
_time_into_pulse = 0;
_current_pulse = _tape->get_next_pulse();
if(_pulse_stepper == nullptr || _current_pulse.length.clock_rate != _pulse_stepper->get_output_rate())
{
_pulse_stepper = std::unique_ptr<SignalProcessing::Stepper>(new SignalProcessing::Stepper(_current_pulse.length.clock_rate, 2000000));
}
}
inline void Tape::push_tape_bit(uint16_t bit)
{
_data_register = (uint16_t)((_data_register >> 1) | (bit << 10));
if(_bits_since_start)
{
_bits_since_start--;
if(_bits_since_start == 7)
{
_interrupt_status &= ~Interrupt::ReceiveDataFull;
}
}
evaluate_interrupts();
}
inline void Tape::reset_tape_input()
{
_bits_since_start = 0;
// _interrupt_status &= ~(Interrupt::ReceiveDataFull | Interrupt::TransmitDataEmpty | 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::evaluate_interrupts()
{
if(!_bits_since_start)
{
if((_data_register&0x3) == 0x1)
{
_interrupt_status |= Interrupt::ReceiveDataFull;
if(_is_in_input_mode) _bits_since_start = 9;
}
}
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)
{
if(_interrupt_status & interrupts)
{
_interrupt_status &= ~interrupts;
if(_delegate) _delegate->tape_did_change_interrupt_status(this);
}
}
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::unique_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 uint8_t Tape::get_data_register()
{
return (uint8_t)(_data_register >> 2);
}
inline void Tape::run_for_cycles(unsigned int number_of_cycles)
{
if(_is_enabled)
{
if(_is_in_input_mode)
{
if(_is_running && _tape != nullptr)
{
while(number_of_cycles--)
{
_time_into_pulse += (unsigned int)_pulse_stepper->step();
if(_time_into_pulse == _current_pulse.length.length)
{
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 >= 0.35 / 2400.0 && pulse_length < 0.7 / 2400.0) _crossings[3] = Tape::Short;
if(pulse_length >= 0.35 / 1200.0 && pulse_length < 0.7 / 1200.0) _crossings[3] = Tape::Long;
}
if(_crossings[0] == Tape::Long && _crossings[1] == Tape::Long)
{
push_tape_bit(0);
_crossings[0] = _crossings[1] = Tape::Recognised;
}
else
{
if(_crossings[0] == Tape::Short && _crossings[1] == Tape::Short && _crossings[2] == Tape::Short && _crossings[3] == Tape::Short)
{
push_tape_bit(1);
_crossings[0] = _crossings[1] =
_crossings[2] = _crossings[3] = Tape::Recognised;
}
}
}
}
}
}
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;
}
}
}
}
}
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