mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-22 12:33:29 +00:00
72 lines
1.9 KiB
C++
72 lines
1.9 KiB
C++
//
|
|
// DiskROM.cpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 07/01/2018.
|
|
// Copyright © 2018 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#include "DiskROM.hpp"
|
|
|
|
using namespace MSX;
|
|
|
|
DiskROM::DiskROM(const std::vector<uint8_t> &rom) :
|
|
WD1770(P1793),
|
|
rom_(rom) {
|
|
set_is_double_density(true);
|
|
}
|
|
|
|
void DiskROM::write(uint16_t address, uint8_t value) {
|
|
switch(address) {
|
|
case 0x7ff8: case 0x7ff9: case 0x7ffa: case 0x7ffb:
|
|
set_register(address, value);
|
|
break;
|
|
case 0x7ffc:
|
|
selected_head_ = value & 1;
|
|
if(drives_[0]) drives_[0]->set_head(selected_head_);
|
|
if(drives_[1]) drives_[1]->set_head(selected_head_);
|
|
break;
|
|
case 0x7ffd: {
|
|
selected_drive_ = value & 1;
|
|
set_drive(drives_[selected_drive_]);
|
|
|
|
bool drive_motor = !!(value & 0x80);
|
|
if(drives_[0]) drives_[0]->set_motor_on(drive_motor);
|
|
if(drives_[1]) drives_[1]->set_motor_on(drive_motor);
|
|
} break;
|
|
}
|
|
}
|
|
|
|
uint8_t DiskROM::read(uint16_t address) {
|
|
if(address >= 0x7ff8 && address < 0x7ffc) {
|
|
return get_register(address);
|
|
}
|
|
if(address == 0x7fff) {
|
|
return (get_data_request_line() ? 0x00 : 0x80) | (get_interrupt_request_line() ? 0x00 : 0x40);
|
|
}
|
|
return rom_[address & 0x3fff];
|
|
}
|
|
|
|
void DiskROM::run_for(HalfCycles half_cycles) {
|
|
// Input clock is going to be 7159090/2 Mhz, but the drive controller
|
|
// needs an 8Mhz clock, so scale up. 8000000/7159090 simplifies to
|
|
// 800000/715909.
|
|
controller_cycles_ += 800000 * half_cycles.as_int();
|
|
WD::WD1770::run_for(Cycles(static_cast<int>(controller_cycles_ / 715909)));
|
|
controller_cycles_ %= 715909;
|
|
}
|
|
|
|
void DiskROM::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive) {
|
|
if(!drives_[drive]) {
|
|
drives_[drive].reset(new Storage::Disk::Drive(8000000, 300, 2));
|
|
drives_[drive]->set_head(selected_head_);
|
|
if(drive == selected_drive_) set_drive(drives_[drive]);
|
|
}
|
|
drives_[drive]->set_disk(disk);
|
|
}
|
|
|
|
void DiskROM::set_head_load_request(bool head_load) {
|
|
// Magic!
|
|
set_head_loaded(head_load);
|
|
}
|