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mirror of https://github.com/TomHarte/CLK.git synced 2024-06-01 06:41:36 +00:00

Put enough in place to get a visual representation of video memory.

Not the correct one, and so as to indicate that the machine isn't booting, surprisingly.
This commit is contained in:
Thomas Harte 2018-04-15 19:35:08 -04:00
parent 335c633884
commit 9bc470027e
3 changed files with 67 additions and 147 deletions

View File

@ -23,16 +23,45 @@ class ConcreteMachine:
public CRTMachine::Machine,
public CPU::MOS6502::BusHandler,
public AppleII::Machine {
public:
private:
struct VideoBusHandler : public AppleII::Video::BusHandler {
public:
VideoBusHandler(uint8_t *ram) : ram_(ram) {}
uint8_t perform_read(uint16_t address) {
return ram_[address];
}
private:
uint8_t *ram_;
};
CPU::MOS6502::Processor<ConcreteMachine, false> m6502_;
VideoBusHandler video_bus_handler_;
std::unique_ptr<AppleII::Video::Video<VideoBusHandler>> video_;
int cycles_into_current_line_ = 0;
Cycles cycles_since_video_update_;
void update_video() {
video_->run_for(cycles_since_video_update_.flush());
}
uint8_t ram_[48*1024];
std::vector<uint8_t> rom_;
std::vector<uint8_t> character_rom_;
uint16_t rom_start_address_;
public:
ConcreteMachine():
m6502_(*this) {
m6502_(*this),
video_bus_handler_(ram_) {
set_clock_rate(1022727);
Memory::Fuzz(ram_, sizeof(ram_));
}
void setup_output(float aspect_ratio) override {
video_.reset(new AppleII::Video);
video_.reset(new AppleII::Video::Video<VideoBusHandler>(video_bus_handler_));
video_->set_character_rom(character_rom_);
}
void close_output() override {
@ -105,33 +134,22 @@ class ConcreteMachine:
auto roms = roms_with_names(
"AppleII",
{
"apple2o.rom"
"apple2o.rom",
"apple2o-character.rom"
});
if(!roms[0]) return false;
if(!roms[0] || !roms[1]) return false;
rom_ = std::move(*roms[0]);
rom_start_address_ = static_cast<uint16_t>(0x10000 - rom_.size());
character_rom_ = std::move(*roms[1]);
return true;
}
void run_for(const Cycles cycles) override {
m6502_.run_for(cycles);
}
private:
CPU::MOS6502::Processor<ConcreteMachine, false> m6502_;
std::unique_ptr<AppleII::Video> video_;
int cycles_into_current_line_ = 0;
Cycles cycles_since_video_update_;
void update_video() {
video_->run_for(cycles_since_video_update_.flush());
}
uint8_t ram_[48*1024];
std::vector<uint8_t> rom_;
uint16_t rom_start_address_;
};
}

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@ -8,132 +8,28 @@
#include "Video.hpp"
using namespace AppleII;
using namespace AppleII::Video;
Video::Video() :
crt_(new Outputs::CRT::CRT(455, 1, Outputs::CRT::DisplayType::NTSC60, 1)) {
// Set a composite sampling function that assumes 1bpp input, and uses just 7 bits per byte.
crt_->set_composite_sampling_function(
"float composite_sample(usampler2D sampler, vec2 coordinate, vec2 icoordinate, float phase, float amplitude)"
"{"
"uint texValue = texture(sampler, coordinate).r;"
"texValue <<= int(icoordinate.x * 8) & 7;"
"return float(texValue & 128u);"
// "uint texValue = texture(sampler, coordinate).r;"
// "texValue <<= uint(icoordinate.x * 7.0) % 7u;"
// "return float(texValue & 128u);"
"}");
// Show only the centre 75% of the TV frame.
crt_->set_video_signal(Outputs::CRT::VideoSignal::Composite);
crt_->set_visible_area(Outputs::CRT::Rect(0.115f, 0.115f, 0.77f, 0.77f));
}
Outputs::CRT::CRT *Video::get_crt() {
return crt_.get();
}
void Video::run_for(const Cycles cycles) {
/*
Addressing scheme used throughout is that column 0 is the first column with pixels in it;
row 0 is the first row with pixels in it.
A frame is oriented around 65 cycles across, 262 lines down.
*/
const int first_sync_line = 220; // A complete guess. Information needed.
const int first_sync_column = 49; // Also a guess.
int int_cycles = cycles.as_int();
while(int_cycles) {
const int cycles_this_line = std::min(65 - column_, int_cycles);
if(row_ >= first_sync_line && row_ < first_sync_line + 3) {
crt_->output_sync(static_cast<unsigned int>(cycles_this_line) * 7);
} else {
const int ending_column = column_ + cycles_this_line;
// The first 40 columns are submitted to the CRT only upon completion;
// they'll be either graphics or blank, depending on which side we are
// of line 192.
if(column_ < 40) {
if(row_ < 192) {
if(!column_) {
pixel_pointer_ = crt_->allocate_write_area(40);
}
// TODO: actually store pixels.
if(ending_column >= 40) {
for(int c = 0; c < 40; ++c) {
pixel_pointer_[c] = static_cast<uint8_t>((c * 6) ^ row_);
}
crt_->output_data(280, 7);
}
} else {
if(ending_column >= 40) {
crt_->output_blank(280);
}
}
}
/*
The left border, sync, right border pattern doesn't depend on whether
there were pixels this row and is output as soon as it is known.
*/
const int first_blank_start = std::max(40, column_);
const int first_blank_end = std::min(first_sync_column, ending_column);
if(first_blank_end > first_blank_start) {
crt_->output_blank(static_cast<unsigned int>(first_blank_end - first_blank_start) * 7);
}
// TODO: colour burst.
const int sync_start = std::max(first_sync_column, column_);
const int sync_end = std::min(first_sync_column + 4, ending_column);
if(sync_end > sync_start) {
crt_->output_sync(static_cast<unsigned int>(sync_end - sync_start) * 7);
}
const int second_blank_start = std::max(first_sync_column + 4, column_);
if(ending_column > second_blank_start) {
crt_->output_blank(static_cast<unsigned int>(ending_column - second_blank_start) * 7);
}
}
int_cycles -= cycles_this_line;
column_ = (column_ + cycles_this_line) % 65;
if(!column_) {
row_ = (row_ + 1) % 262;
// Add an extra half a colour cycle of blank; this isn't counted in the run_for
// count explicitly but is promised.
crt_->output_blank(1);
}
}
}
void Video::set_graphics_mode() {
printf("Graphics mode\n");
}
void Video::set_text_mode() {
printf("Text mode\n");
}
void Video::set_mixed_mode(bool mixed_mode) {
printf("Mixed mode: %s\n", mixed_mode ? "true" : "false");
}
void Video::set_video_page(int page) {
printf("Video page: %d\n", page);
}
void Video::set_low_resolution() {
printf("Low resolution\n");
}
void Video::set_high_resolution() {
printf("High resolution\n");
}
//void Video::set_graphics_mode() {
// printf("Graphics mode\n");
//}
//
//void Video::set_text_mode() {
// printf("Text mode\n");
//}
//
//void Video::set_mixed_mode(bool mixed_mode) {
// printf("Mixed mode: %s\n", mixed_mode ? "true" : "false");
//}
//
//void Video::set_video_page(int page) {
// printf("Video page: %d\n", page);
//}
//
//void Video::set_low_resolution() {
// printf("Low resolution\n");
//}
//
//void Video::set_high_resolution() {
// printf("High resolution\n");
//}

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@ -0,0 +1,6 @@
ROM files would ordinarily go here; they are copyright Apple so are not included.
Expected files:
apple2o.rom — a 12kb image of the original Apple II's ROMs.
apple2o-character.rom — a 2kb image of the original Apple II's character ROM.