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Updated to latest information on interrupt timing.

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This commit is contained in:
Thomas Harte 2016-03-18 21:11:25 -04:00
parent 61e880de03
commit b074860031
1 changed files with 17 additions and 5 deletions
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22
Machines/Electron/Electron.cpp
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@ -22,13 +22,15 @@ namespace {
static const unsigned int crt_cycles_per_line = crt_cycles_multiplier * cycles_per_line;
static const unsigned int field_divider_line = 312; // i.e. the line, simultaneous with which, the first field's sync ends. So if
// the first line with pixels in field 1 is the 20th in the frame, the first line
// with pixels in field 2 will be 20+field_divider_line
static const unsigned int first_graphics_line = 38;
// the first line with pixels in field 1 is the 20th in the frame, the first line
// with pixels in field 2 will be 20+field_divider_line
static const unsigned int first_graphics_line = 31;
static const unsigned int first_graphics_cycle = 33;
static const unsigned int real_time_clock_interrupt_line = 100;
static const unsigned int display_end_interrupt_line = 256;
static const unsigned int real_time_clock_interrupt_1 = 16704;
static const unsigned int real_time_clock_interrupt_2 = 56704;
}
#define graphics_line(v) ((((v) >> 7) - first_graphics_line + field_divider_line) % field_divider_line)
@ -358,6 +360,9 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
// printf("%04x: %02x (%d)\n", address, *value, _fieldCycles);
// }
// const int end_of_field =
// if (_frameCycles < (256 + first_graphics_line) << 7))
const unsigned int pixel_line_clock = _frameCycles;// + 128 - first_graphics_cycle + 80;
const unsigned int line_before_cycle = graphics_line(pixel_line_clock);
const unsigned int line_after_cycle = graphics_line(pixel_line_clock + cycles);
@ -368,13 +373,20 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
{
switch(line_before_cycle)
{
case real_time_clock_interrupt_line: signal_interrupt(Interrupt::RealTimeClock); break;
// case real_time_clock_interrupt_line: signal_interrupt(Interrupt::RealTimeClock); break;
// case real_time_clock_interrupt_line+1: clear_interrupt(Interrupt::RealTimeClock); break;
case display_end_interrupt_line: signal_interrupt(Interrupt::DisplayEnd); break;
// case display_end_interrupt_line+1: clear_interrupt(Interrupt::DisplayEnd); break;
}
}
if(
(pixel_line_clock < real_time_clock_interrupt_1 && pixel_line_clock + cycles >= real_time_clock_interrupt_1) ||
(pixel_line_clock < real_time_clock_interrupt_2 && pixel_line_clock + cycles >= real_time_clock_interrupt_2))
{
signal_interrupt(Interrupt::RealTimeClock);
}
_frameCycles += cycles;
// deal with frame wraparound by updating the two dependent subsystems