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I think the horizontal interrupt is blank, not sync.

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This commit is contained in:
Thomas Harte 2019-11-07 22:00:50 -05:00
parent fc8021c0b0
commit 5e1570258d
3 changed files with 24 additions and 16 deletions
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2
Machines/AtariST/AtariST.cpp
View File

@ -503,7 +503,7 @@ class ConcreteMachine:
mc68000_.set_interrupt_level(6);
} else if(video_->vsync()) {
mc68000_.set_interrupt_level(4);
} else if(video_->hsync()) {
} else if(video_->hblank()) {
mc68000_.set_interrupt_level(2);
} else {
mc68000_.set_interrupt_level(0);

36
Machines/AtariST/Video.cpp
View File

@ -318,8 +318,8 @@ void Video::output_border(int duration) {
crt_.output_level(duration);
}
bool Video::hsync() {
return horizontal_.sync;
bool Video::hblank() {
return horizontal_.blank;
}
bool Video::vsync() {
@ -333,27 +333,35 @@ bool Video::display_enabled() {
HalfCycles Video::get_next_sequence_point() {
// The next sequence point will be whenever display_enabled, vsync or hsync next changes.
// If this is a vertically-enabled line, and right now is either before graphics display,
// or during it, then it's display enabled that will change next.
// Sequence of events within a line:
//
// 1) blank disabled;
// 2) de enabled;
// 3) de disabled;
// 4) blank enabled;
// 5) end-of-line, potential vertical event.
const auto horizontal_timings = horizontal_parameters(field_frequency_);
// Test for end of blank.
if(x < horizontal_timings.reset_blank) return HalfCycles(horizontal_timings.reset_blank - x);
// If this is a vertically-enabled line, check for the display enable boundaries.
if(vertical_.enable) {
if(x < horizontal_timings.set_enable) {
return HalfCycles(horizontal_timings.set_enable - x);
} else if(x < horizontal_timings.reset_enable) {
return HalfCycles(horizontal_timings.reset_enable - x);
}
if(x < horizontal_timings.set_enable) return HalfCycles(horizontal_timings.set_enable - x);
if(x < horizontal_timings.reset_enable) return HalfCycles(horizontal_timings.reset_enable - x);
}
// Otherwise, if this is before or during horizontal sync then that's the next event.
if(x < line_length_ - 50) return HalfCycles(line_length_ - 50 - x);
else if(x < line_length_ - 10) return HalfCycles(line_length_ - 10 - x);
// Test for beginning of blank.
if(x < horizontal_timings.set_blank) return HalfCycles(horizontal_timings.set_blank - x);
// Okay, then, it depends on the next line. If the next line is the start or end of vertical sync,
// it's that. Otherwise it's the beginning of display enable on the next line.
// it's that.
const auto vertical_timings = horizontal_parameters(field_frequency_);
if(y+1 == vertical_timings.length || y+1 == 3) return HalfCycles(line_length_ - x);
return HalfCycles(line_length_ + horizontal_timings.set_enable - x);
// It wasn't any of those, so it's blank disabled on the next line.
return HalfCycles(line_length_ + horizontal_timings.reset_blank - x);
}
// MARK: - IO dispatch

2
Machines/AtariST/Video.hpp
View File

@ -39,7 +39,7 @@ class Video {
*/
HalfCycles get_next_sequence_point();
bool hsync();
bool hblank();
bool vsync();
bool display_enabled();