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Made an initial stab at outputting half the correct pixels.

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This commit is contained in:
Thomas Harte 2017-06-06 08:55:07 -04:00
parent ef4b2f963d
commit 6f7037b2b1
2 changed files with 19 additions and 9 deletions
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27
Machines/ZX8081/ZX8081.cpp
View File

@ -23,9 +23,9 @@ Machine::Machine() :
}
int Machine::perform_machine_cycle(const CPU::Z80::MachineCycle &cycle) {
cycles_since_display_update_ += cycle.length;
cycles_since_display_update_ += (unsigned int)cycle.length;
uint8_t r;
uint16_t r = 0;
uint16_t address = cycle.address ? *cycle.address : 0;
switch(cycle.operation) {
case CPU::Z80::BusOperation::Output:
@ -37,24 +37,32 @@ int Machine::perform_machine_cycle(const CPU::Z80::MachineCycle &cycle) {
case CPU::Z80::BusOperation::Input:
if((address&7) == 6) {
set_vsync(true);
line_counter_ = 0;
}
*cycle.value = 0xff;
break;
case CPU::Z80::BusOperation::Interrupt:
set_hsync(true);
line_counter_ = (line_counter_ + 1) & 7;
*cycle.value = 0xff;
break;
case CPU::Z80::BusOperation::ReadOpcode:
set_hsync(false);
r = (uint8_t)get_value_of_register(CPU::Z80::Register::R);
r = (uint8_t)get_value_of_register(CPU::Z80::Register::Refresh);
set_interrupt_line(!(r & 0x40));
case CPU::Z80::BusOperation::Read:
if((address & 0xc000) == 0x0000) *cycle.value = rom_[address & (rom_.size() - 1)];
else if((address & 0x4000) == 0x4000) {
uint8_t value = ram_[address & 1023];
if(address&0x8000 && !(value & 0x40) && cycle.operation == CPU::Z80::BusOperation::ReadOpcode && !get_halt_line()) {
size_t char_address = (size_t)((r & 0xff00) | ((value & 0x3f) << 3) | line_counter_);
if((char_address & 0xc000) == 0x0000) {
uint8_t mask = (value & 0x80) ? 0xff : 0x00;
value = rom_[char_address & (rom_.size() - 1)] ^ mask;
}
// TODO: character lookup.
output_byte(value);
*cycle.value = 0;
@ -154,8 +162,8 @@ void Machine::output_level(unsigned int number_of_cycles) {
}
void Machine::output_data() {
unsigned int data_length = (unsigned int)(line_data_pointer_ - line_data_);
crt_->output_data(data_length, 1);
unsigned int data_length = ((unsigned int)(line_data_pointer_ - line_data_)) ;
crt_->output_data(data_length * 1, 1);
line_data_pointer_ = line_data_ = nullptr;
cycles_since_display_update_ -= data_length;
}
@ -175,10 +183,11 @@ void Machine::output_byte(uint8_t byte) {
}
if(line_data_) {
line_data_pointer_[0] = byte;
line_data_pointer_[1] = byte;
line_data_pointer_[2] = byte;
line_data_pointer_[3] = byte;
uint8_t mask = 0x80;
for(int c = 0; c < 4; c++) {
line_data_pointer_[c] = (byte & mask) ? 0xff : 0x00;
mask >>= 1;
}
line_data_pointer_ += 4;
}
}

1
Machines/ZX8081/ZX8081.hpp
View File

@ -53,6 +53,7 @@ class Machine:
bool vsync_, hsync_;
bool is_sync_;
uint8_t *line_data_, *line_data_pointer_;
int line_counter_;
unsigned int cycles_since_display_update_;
void update_display();