mirror of https://github.com/bsnes-emu/bsnes.git
87 lines
2.4 KiB
C++
87 lines
2.4 KiB
C++
#include <ms/ms.hpp>
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namespace MasterSystem {
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Bus bus;
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auto Bus::read(uint16 addr) -> uint8 {
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if(auto data = cartridge.read(addr)) return data();
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if(addr >= 0xc000) return ram[addr & 0x1fff];
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return 0x00;
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}
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auto Bus::write(uint16 addr, uint8 data) -> void {
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if(cartridge.write(addr, data)) return;
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if(addr >= 0xc000) ram[addr & 0x1fff] = data;
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}
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auto Bus::in(uint8 addr) -> uint8 {
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switch(addr >> 6) {
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case 0: {
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if(system.model() == Model::GameGear) {
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bool start = !platform->inputPoll(ID::Port::Hardware, ID::Device::GameGearControls, 6);
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return start << 7 | 0x7f;
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}
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return 0xff; //SMS1 = MDR, SMS2 = 0xff
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}
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case 1: {
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return !addr.bit(0) ? vdp.vcounter() : vdp.hcounter();
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}
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case 2: {
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return !addr.bit(0) ? vdp.data() : vdp.status();
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}
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case 3: {
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if(system.model() == Model::MasterSystem) {
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bool reset = !platform->inputPoll(ID::Port::Hardware, ID::Device::MasterSystemControls, 0);
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auto port1 = peripherals.controllerPort1->readData();
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auto port2 = peripherals.controllerPort2->readData();
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if(addr.bit(0) == 0) {
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return port1.bits(0,5) << 0 | port2.bits(0,1) << 6;
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} else {
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return port2.bits(2,5) << 0 | reset << 4 | 1 << 5 | port1.bit(6) << 6 | port2.bit(6) << 7;
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}
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}
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if(system.model() == Model::GameGear) {
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bool up = !platform->inputPoll(ID::Port::Hardware, ID::Device::GameGearControls, 0);
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bool down = !platform->inputPoll(ID::Port::Hardware, ID::Device::GameGearControls, 1);
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bool left = !platform->inputPoll(ID::Port::Hardware, ID::Device::GameGearControls, 2);
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bool right = !platform->inputPoll(ID::Port::Hardware, ID::Device::GameGearControls, 3);
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bool one = !platform->inputPoll(ID::Port::Hardware, ID::Device::GameGearControls, 4);
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bool two = !platform->inputPoll(ID::Port::Hardware, ID::Device::GameGearControls, 5);
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if(!up && !down) up = 1, down = 1;
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if(!left && !right) left = 1, right = 1;
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if(addr.bit(0) == 0) {
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return up << 0 | down << 1 | left << 2 | right << 3 | one << 4 | two << 5 | 1 << 6 | 1 << 7;
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} else {
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return 0xff;
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}
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}
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return 0xff;
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}
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}
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return 0xff;
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}
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auto Bus::out(uint8 addr, uint8 data) -> void {
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switch(addr >> 6) {
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case 2: {
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return !addr.bit(0) ? vdp.data(data) : vdp.control(data);
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}
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case 3: {
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return; //unmapped
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}
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}
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}
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}
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