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Merge pull request #179 from TomHarte/AYDirection

Makes various AY input/output fixes, and a few 8255 fixes along the way
This commit is contained in:
Thomas Harte 2017-08-07 19:58:39 -04:00 committed by GitHub
commit d73dcbb268
3 changed files with 28 additions and 8 deletions

View File

@ -26,8 +26,17 @@ template <class T> class i8255 {
void set_register(int address, uint8_t value) {
switch(address & 3) {
case 0: outputs_[0] = value; port_handler_.set_value(0, value); break;
case 1: outputs_[1] = value; port_handler_.set_value(1, value); break;
case 0:
if(!(control_ & 0x10)) {
// TODO: so what would output be when switching from input to output mode?
outputs_[0] = value; port_handler_.set_value(0, value);
}
break;
case 1:
if(!(control_ & 0x02)) {
outputs_[1] = value; port_handler_.set_value(1, value);
}
break;
case 2: outputs_[2] = value; port_handler_.set_value(2, value); break;
case 3:
if(value & 0x80) {
@ -46,9 +55,13 @@ template <class T> class i8255 {
uint8_t get_register(int address) {
switch(address & 3) {
case 0: return port_handler_.get_value(0);
case 1: return port_handler_.get_value(1);
case 2: return port_handler_.get_value(2);
case 0: return (control_ & 0x10) ? port_handler_.get_value(0) : outputs_[0];
case 1: return (control_ & 0x02) ? port_handler_.get_value(1) : outputs_[1];
case 2: {
if(!(control_ & 0x09)) return outputs_[2];
uint8_t input = port_handler_.get_value(2);
return ((control_ & 0x01) ? (input & 0x0f) : (outputs_[2] & 0x0f)) | ((control_ & 0x08) ? (input & 0xf0) : (outputs_[2] & 0xf0));
}
case 3: return control_;
}
return 0xff;

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@ -169,10 +169,11 @@ void AY38910::evaluate_output_volume() {
#pragma mark - Register manipulation
void AY38910::select_register(uint8_t r) {
selected_register_ = r & 0xf;
selected_register_ = r;
}
void AY38910::set_register_value(uint8_t value) {
if(selected_register_ > 15) return;
registers_[selected_register_] = value;
if(selected_register_ < 14) {
int selected_register = selected_register_;
@ -226,7 +227,12 @@ uint8_t AY38910::get_register_value() {
0xe0, 0xe0, 0xe0, 0x00, 0x00, 0xf0, 0x00, 0x00
};
return registers_[selected_register_] | register_masks[selected_register_];
if(selected_register_ > 15) return 0xff;
switch(selected_register_) {
default: return registers_[selected_register_] & ~register_masks[selected_register_];
case 14: return (registers_[0x7] & 0x40) ? registers_[14] : port_inputs_[0];
case 15: return (registers_[0x7] & 0x80) ? registers_[15] : port_inputs_[1];
}
}
#pragma mark - Port handling
@ -236,7 +242,7 @@ uint8_t AY38910::get_port_output(bool port_b) {
}
void AY38910::set_port_input(bool port_b, uint8_t value) {
registers_[port_b ? 15 : 14] = value;
port_inputs_[port_b ? 1 : 0] = value;
update_bus();
}

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@ -59,6 +59,7 @@ class AY38910: public ::Outputs::Filter<AY38910> {
private:
int selected_register_;
uint8_t registers_[16], output_registers_[16];
uint8_t port_inputs_[2];
int master_divider_;