CLK/Machines/Enterprise/Nick.cpp

//
//  Nick.cpp
//  Clock Signal
//
//  Created by Thomas Harte on 14/06/2021.
//  Copyright © 2021 Thomas Harte. All rights reserved.
//

#include "Nick.hpp"

#include <cstdio>

using namespace Enterprise;

Nick::Nick(const uint8_t *ram) :
	crt_(16 * 57, 16, Outputs::Display::Type::PAL50, Outputs::Display::InputDataType::Red4Green4Blue4),
	ram_(ram) {

	// Just use RGB for now.
	crt_.set_display_type(Outputs::Display::DisplayType::RGB);
}

void Nick::write(uint16_t address, uint8_t value) {
	printf("Nick write: %02x -> %d\n", value, address & 3);
	switch(address & 3) {
		default:
			printf("Unhandled\n");
		break;

		case 2:
			line_parameter_base_ = uint16_t((line_parameter_base_ & 0xf000) | (value << 4));
		break;
		case 3:
			line_parameter_base_ = uint16_t((line_parameter_base_ & 0x0ff0) | (value << 12));

			// Still a mystery to me: the exact meaning of the top two bits here. For now
			// just treat a 0 -> 1 transition of the MSB as a forced frame restart.
			if((value^line_parameter_control_) & value & 0x80) {
				// TODO: restart frame.
				printf("Should restart frame from %04x\n", line_parameter_base_);
			}
			line_parameter_control_ = value & 0xc0;
		break;
	}
}

uint8_t Nick::read([[maybe_unused]] uint16_t address) {
	return 0xff;
}

void Nick::run_for(HalfCycles) {
}

// MARK: - CRT passthroughs.

void Nick::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
	crt_.set_scan_target(scan_target);
}

Outputs::Display::ScanStatus Nick::get_scaled_scan_status() const {
	return crt_.get_scaled_scan_status();
}