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Add faulty attempt at adjustment period.

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This commit is contained in:
Thomas Harte 2024-09-30 23:47:27 -04:00
parent 0d0e1083e6
commit 2eb9fb6a08
1 changed files with 19 additions and 101 deletions
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120
Components/6845/CRTC6845.hpp
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@ -189,7 +189,6 @@ template <class BusHandlerT, Personality personality, CursorType cursor_type> cl
bool eom_latched_ = false;
bool extra_scanline_ = false;
uint16_t next_row_address_ = 0;
bool adjustment_in_progress_ = false;
bool odd_field_ = false;
void run_for(Cycles cycles) {
@ -212,7 +211,7 @@ template <class BusHandlerT, Personality personality, CursorType cursor_type> cl
//
const bool character_total_hit = character_counter_ == layout_.horizontal.total;
const uint8_t lines_per_row = layout_.interlace_mode_ == InterlaceMode::InterlaceSyncAndVideo ? layout_.vertical.end_row & ~1 : layout_.vertical.end_row;
const bool row_end_hit = bus_state_.row_address == lines_per_row && !adjustment_in_progress_;
const bool row_end_hit = bus_state_.row_address == lines_per_row && !is_in_adjustment_period_;
const bool new_frame =
character_total_hit && eof_latched_ &&
(
@ -253,10 +252,23 @@ template <class BusHandlerT, Personality personality, CursorType cursor_type> cl
//
if(new_frame) {
eom_latched_ = eof_latched_ = false;
is_in_adjustment_period_ = eom_latched_ = eof_latched_ = false;
} else {
eom_latched_ |= character_counter_ == 1 && row_end_hit && row_counter_ == layout_.vertical.total;
eof_latched_ |= character_counter_ == 2 && eom_latched_ && !adjustment_in_progress_;
if(eom_latched_ && character_counter_ == 2) {
eof_latched_ |= adjustment_counter_ == layout_.vertical.adjust;
is_in_adjustment_period_ |= eom_latched_ && !eof_latched_;
}
}
if(character_total_hit) {
if(is_in_adjustment_period_) {
adjustment_counter_ = (adjustment_counter_ + 1) & 31;
} else if(eof_latched_) {
is_in_adjustment_period_ = false;
adjustment_counter_ = 0;
}
}
//
@ -306,7 +318,7 @@ template <class BusHandlerT, Personality personality, CursorType cursor_type> cl
line_is_visible_ = true;
} else if(line_is_visible_ && row_counter_ == layout_.vertical.displayed) {
line_is_visible_ = false;
// ++field_counter_;
++bus_state_.field_count;
}
//
@ -347,101 +359,6 @@ template <class BusHandlerT, Personality personality, CursorType cursor_type> cl
bus_handler_.perform_bus_cycle_phase2(bus_state_);
}
// inline void do_end_of_line() {
// if constexpr (cursor_type != CursorType::None) {
// // Check for cursor disable.
// // TODO: this is handled differently on the EGA, should I ever implement that.
// is_cursor_line_ &= bus_state_.row_address != layout_.vertical.end_cursor;
// }
//
// // Check for end of vertical sync.
// if(bus_state_.vsync) {
// vsync_counter_ = (vsync_counter_ + 1) & 15;
// // On the UM6845R and AMS40226, honour the programmed vertical sync time; on the other CRTCs
// // always use a vertical sync count of 16.
// switch(personality) {
// case Personality::HD6845S:
// case Personality::AMS40226:
// bus_state_.vsync = vsync_counter_ != layout_.vertical.sync_lines;
// break;
// default:
// bus_state_.vsync = vsync_counter_ != 0;
// break;
// }
// }
//
// if(is_in_adjustment_period_) {
// line_counter_++;
// if(line_counter_ == layout_.vertical.adjust) {
// is_in_adjustment_period_ = false;
// do_end_of_frame();
// }
// } else {
// // Advance vertical counter.
// if(bus_state_.row_address == layout_.end_row()) {
// bus_state_.row_address = 0;
// line_address_ = end_of_line_address_;
//
// // Check for entry into the overflow area.
// if(line_counter_ == layout_.vertical.total) {
// if(layout_.vertical.adjust) {
// line_counter_ = 0;
// is_in_adjustment_period_ = true;
// } else {
// do_end_of_frame();
// }
// } else {
// line_counter_ = (line_counter_ + 1) & 0x7f;
// }
//
// // Check for start of vertical sync.
// if(line_counter_ == layout_.vertical.start_sync) {
// bus_state_.vsync = true;
// vsync_counter_ = 0;
// }
//
// // Check for end of visible lines.
// if(line_counter_ == layout_.vertical.displayed) {
// line_is_visible_ = false;
// }
// } else {
// bus_state_.row_address = (bus_state_.row_address + 1) & 0x1f;
// }
// }
//
// bus_state_.refresh_address = line_address_;
// character_counter_ = 0;
// character_is_visible_ = (layout_.horizontal.displayed != 0);
//
// if constexpr (cursor_type != CursorType::None) {
// // Check for cursor enable.
// is_cursor_line_ |= bus_state_.row_address == layout_.vertical.start_cursor;
//
// switch(cursor_type) {
// // MDA-style blinking.
// // https://retrocomputing.stackexchange.com/questions/27803/what-are-the-blinking-rates-of-the-caret-and-of-blinking-text-on-pc-graphics-car
// // gives an 8/8 pattern for regular blinking though mode 11 is then just a guess.
// case CursorType::MDA:
// switch(layout_.cursor_flags) {
// case 0b11: is_cursor_line_ &= (bus_state_.field_count & 8) < 3; break;
// case 0b00: is_cursor_line_ &= bool(bus_state_.field_count & 8); break;
// case 0b01: is_cursor_line_ = false; break;
// case 0b10: is_cursor_line_ = true; break;
// default: break;
// }
// break;
// }
// }
// }
//
// inline void do_end_of_frame() {
// line_counter_ = 0;
// line_is_visible_ = true;
// line_address_ = layout_.start_address;
// bus_state_.refresh_address = line_address_;
// ++bus_state_.field_count;
// }
BusHandlerT &bus_handler_;
BusState bus_state_;
@ -489,7 +406,8 @@ template <class BusHandlerT, Personality personality, CursorType cursor_type> cl
int selected_register_ = 0;
uint8_t character_counter_ = 0;
uint8_t row_counter_ = 0, next_row_counter_ = 0;;
uint8_t row_counter_ = 0, next_row_counter_ = 0;
uint8_t adjustment_counter_ = 0;
bool character_is_visible_ = false, line_is_visible_ = false, is_first_scanline_ = false;