Proceeds the ColecoVision to booting.

This commit is contained in:
Thomas Harte 2018-02-24 18:14:38 -05:00
parent 5530b96446
commit 23c47e21de
4 changed files with 139 additions and 4 deletions

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@ -8,11 +8,141 @@
#include "ColecoVision.hpp"
#include "../../Processors/Z80/Z80.hpp"
#include "../../Components/9918/9918.hpp"
#include "../CRTMachine.hpp"
#include "../../ClockReceiver/ForceInline.hpp"
namespace Coleco {
namespace Vision {
class ConcreteMachine:
public Machine {
public Machine,
public CPU::Z80::BusHandler,
public CRTMachine::Machine {
public:
ConcreteMachine() : z80_(*this) {
set_clock_rate(3579545);
}
void setup_output(float aspect_ratio) override {
vdp_.reset(new TI::TMS9918(TI::TMS9918::TMS9918A));
get_crt()->set_output_device(Outputs::CRT::OutputDevice::Television);
}
void close_output() override {
vdp_.reset();
}
Outputs::CRT::CRT *get_crt() override {
return vdp_->get_crt();
}
Outputs::Speaker::Speaker *get_speaker() override {
return nullptr;
}
void run_for(const Cycles cycles) override {
z80_.run_for(cycles);
}
// Obtains the system ROMs.
bool set_rom_fetcher(const std::function<std::vector<std::unique_ptr<std::vector<uint8_t>>>(const std::string &machine, const std::vector<std::string> &names)> &roms_with_names) override {
auto roms = roms_with_names(
"ColecoVision",
{
"coleco.rom"
});
if(!roms[0]) return false;
bios_ = *roms[0];
bios_.resize(8192);
return true;
}
// MARK: Z80::BusHandler
forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
if(time_until_interrupt_ > 0) {
time_until_interrupt_ -= cycle.length;
if(time_until_interrupt_ <= HalfCycles(0)) {
z80_.set_non_maskable_interrupt_line(true, time_until_interrupt_);
}
}
uint16_t address = cycle.address ? *cycle.address : 0x0000;
switch(cycle.operation) {
case CPU::Z80::PartialMachineCycle::ReadOpcode:
case CPU::Z80::PartialMachineCycle::Read:
if(address < 0x2000) {
*cycle.value = bios_[address];
} else if(address >= 0x6000 && address < 0x8000) {
*cycle.value = ram_[address & 1023];
} else {
*cycle.value = 0xff;
}
break;
case CPU::Z80::PartialMachineCycle::Write:
if(address >= 0x6000 && address < 0x8000) {
ram_[address & 1023] = *cycle.value;
}
break;
case CPU::Z80::PartialMachineCycle::Input:
switch((address >> 5) & 7) {
case 5:
vdp_->run_for(time_since_vdp_update_.flush());
*cycle.value = vdp_->get_register(address);
z80_.set_non_maskable_interrupt_line(vdp_->get_interrupt_line());
time_until_interrupt_ = vdp_->get_time_until_interrupt();
break;
default:
*cycle.value = 0xff;
break;
}
break;
case CPU::Z80::PartialMachineCycle::Output:
switch((address >> 5) & 7) {
case 5:
vdp_->run_for(time_since_vdp_update_.flush());
vdp_->set_register(address, *cycle.value);
z80_.set_non_maskable_interrupt_line(vdp_->get_interrupt_line());
time_until_interrupt_ = vdp_->get_time_until_interrupt();
break;
default: break;
}
break;
default:
break;
}
time_since_vdp_update_ += cycle.length;
return HalfCycles(0);
}
void flush() {
vdp_->run_for(time_since_vdp_update_.flush());
}
private:
CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
std::unique_ptr<TI::TMS9918> vdp_;
std::vector<uint8_t> bios_;
uint8_t ram_[1024];
HalfCycles time_since_vdp_update_;
HalfCycles time_until_interrupt_;
};
}

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@ -1001,12 +1001,12 @@ bool ProcessorBase::get_interrupt_line() {
return irq_line_;
}
void ProcessorBase::set_non_maskable_interrupt_line(bool value, int offset) {
void ProcessorBase::set_non_maskable_interrupt_line(bool value, HalfCycles offset) {
// NMIs are edge triggered and cannot be masked.
nmi_line_ = value;
if(value) {
request_status_ |= Interrupt::NMI;
if(offset < 0) {
if(offset.as_int() < 0) {
last_request_status_ |= Interrupt::NMI;
}
}

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@ -206,7 +206,7 @@ class ProcessorBase: public ProcessorStorage {
@param offset See discussion in set_interrupt_line.
*/
inline void set_non_maskable_interrupt_line(bool value, int offset = 0);
inline void set_non_maskable_interrupt_line(bool value, HalfCycles offset = 0);
/*!
Gets the value of the non-maskable interrupt line.

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@ -0,0 +1,5 @@
ROM files would ordinarily go here; the copyright status of these is uncertain so they have not been included in this repository.
Expected files:
coleco.rom; an 8kb image of the ColecoVision's BIOS ROM.