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Attempt to wire in a CRTC.

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This commit is contained in:
Thomas Harte 2023-11-22 12:53:09 -05:00
parent 2af6259963
commit 80b2ccd418
1 changed files with 116 additions and 11 deletions
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127
Machines/PCCompatible/PCCompatible.cpp
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@ -17,10 +17,13 @@
#include "../../InstructionSets/x86/Instruction.hpp"
#include "../../InstructionSets/x86/Perform.hpp"
#include "../../Components/AudioToggle/AudioToggle.hpp"
#include "../../Components/6845/CRTC6845.hpp"
#include "../../Components/8255/i8255.hpp"
#include "../../Components/AudioToggle/AudioToggle.hpp"
#include "../../Numeric/RegisterSizes.hpp"
#include "../../Outputs/CRT/CRT.hpp"
#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
#include "../AudioProducer.hpp"
@ -32,6 +35,70 @@
namespace PCCompatible {
class MDA {
public:
MDA() :
crtc_(Motorola::CRTC::Personality::HD6845S, outputter_),
crt_(873, 9, 382, 3, Outputs::Display::InputDataType::Luminance1)
{
crt_.set_visible_area(Outputs::Display::Rect(0.1072f, 0.1f, 0.842105263157895f, 0.842105263157895f));
crt_.set_display_type(Outputs::Display::DisplayType::CompositeMonochrome);
}
void run_for(Cycles cycles) {
// I _think_ the MDA's CRTC is clocked at 14/9ths the PIT clock.
// Do that conversion here.
full_clock_ += 14 * cycles.as<int>();
crtc_.run_for(Cycles(full_clock_ / 9));
full_clock_ %= 9;
}
template <int address>
void write(uint8_t value) {
if constexpr (address & 0x8) {
printf("TODO: write MDA control %02x\n", value);
} else {
if constexpr (address & 0x1) {
crtc_.set_register(value);
} else {
crtc_.select_register(value);
}
}
}
template <int address>
uint8_t read() {
if constexpr (address & 0x8) {
printf("TODO: read MDA control\n");
return 0xff;
} else {
return crtc_.get_register();
}
}
// MARK: - Call-ins for ScanProducer.
void set_scan_target(Outputs::Display::ScanTarget *scan_target) {
crt_.set_scan_target(scan_target);
}
Outputs::Display::ScanStatus get_scaled_scan_status() const {
return crt_.get_scaled_scan_status() / 4.0f;
}
private:
struct CRTCOutputter {
void perform_bus_cycle_phase1(const Motorola::CRTC::BusState &) {
printf("");
}
void perform_bus_cycle_phase2(const Motorola::CRTC::BusState &) {}
} outputter_;
Motorola::CRTC::CRTC6845<CRTCOutputter> crtc_;
Outputs::CRT::CRT crt_;
int full_clock_;
};
struct PCSpeaker {
PCSpeaker() :
toggle(queue),
@ -425,7 +492,8 @@ struct Memory {
class IO {
public:
IO(PIT &pit, DMA &dma, PPI &ppi, PIC &pic) : pit_(pit), dma_(dma), ppi_(ppi), pic_(pic) {}
IO(PIT &pit, DMA &dma, PPI &ppi, PIC &pic, MDA &mda) :
pit_(pit), dma_(dma), ppi_(ppi), pic_(pic), mda_(mda) {}
template <typename IntT> void out(uint16_t port, IntT value) {
switch(port) {
@ -476,10 +544,38 @@ class IO {
printf("TODO: DMA page write of %02x at %04x\n", value, port);
break;
case 0x03b0: case 0x03b1: case 0x03b2: case 0x03b3:
case 0x03b4: case 0x03b5: case 0x03b6: case 0x03b7:
case 0x03b8: case 0x03b9: case 0x03ba: case 0x03bb:
case 0x03bc: case 0x03bd: case 0x03be: case 0x03bf:
case 0x03b0:
case 0x03b2:
case 0x03b4:
case 0x03b6:
if constexpr (std::is_same_v<IntT, uint16_t>) {
mda_.write<0>(value);
mda_.write<1>(value >> 8);
} else {
mda_.write<0>(value);
}
break;
case 0x03b1:
case 0x03b3:
case 0x03b5:
case 0x03b7:
if constexpr (std::is_same_v<IntT, uint16_t>) {
mda_.write<1>(value);
mda_.write<0>(value >> 8);
} else {
mda_.write<1>(value);
}
break;
case 0x03b8:
case 0x03b9:
case 0x03ba:
case 0x03bb:
case 0x03bc:
case 0x03bd:
case 0x03be:
case 0x03bf:
printf("TODO: MDA write of %02x at %04x\n", value, port);
break;
@ -532,6 +628,7 @@ class IO {
DMA &dma_;
PPI &ppi_;
PIC &pic_;
MDA &mda_;
};
class FlowController {
@ -586,7 +683,7 @@ class ConcreteMachine:
ppi_handler_(speaker_),
pit_(pit_observer_),
ppi_(ppi_handler_),
context(pit_, dma_, ppi_, pic_)
context(pit_, dma_, ppi_, pic_, mda_)
{
// Use clock rate as a MIPS count; keeping it as a multiple or divisor of the PIT frequency is easy.
static constexpr int pit_frequency = 1'193'182;
@ -634,6 +731,11 @@ class ConcreteMachine:
pit_.run_for(1);
++speaker_.cycles_since_update;
//
// Advance CRTC at a more approximate rate.
//
mda_.run_for(Cycles(3));
//
// Perform one CPU instruction every three PIT cycles.
// i.e. CPU instruction rate is 1/3 * ~1.19Mhz ~= 0.4 MIPS.
@ -692,9 +794,11 @@ class ConcreteMachine:
}
// MARK: - ScanProducer.
void set_scan_target([[maybe_unused]] Outputs::Display::ScanTarget *scan_target) override {}
void set_scan_target(Outputs::Display::ScanTarget *scan_target) override {
mda_.set_scan_target(scan_target);
}
Outputs::Display::ScanStatus get_scaled_scan_status() const override {
return Outputs::Display::ScanStatus();
return mda_.get_scaled_scan_status();
}
// MARK: - AudioProducer.
@ -713,6 +817,7 @@ class ConcreteMachine:
PIC pic_;
DMA dma_;
PCSpeaker speaker_;
MDA mda_;
PITObserver pit_observer_;
i8255PortHandler ppi_handler_;
@ -721,11 +826,11 @@ class ConcreteMachine:
PPI ppi_;
struct Context {
Context(PIT &pit, DMA &dma, PPI &ppi, PIC &pic) :
Context(PIT &pit, DMA &dma, PPI &ppi, PIC &pic, MDA &mda) :
segments(registers),
memory(registers, segments),
flow_controller(registers, segments),
io(pit, dma, ppi, pic)
io(pit, dma, ppi, pic, mda)
{
reset();
}