mirror of
https://github.com/TomHarte/CLK.git
synced 2024-06-25 18:30:07 +00:00
Starts to formalise the ADB bus.
This commit is contained in:
Thomas Harte
parent
46bd20b5e0
commit
17bac4c8cf
93
Machines/Apple/ADB/Bus.cpp
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93
Machines/Apple/ADB/Bus.cpp
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@ -0,0 +1,93 @@
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//
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// Bus.cpp
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// Clock Signal
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//
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// Created by Thomas Harte on 10/02/2021.
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// Copyright © 2021 Thomas Harte. All rights reserved.
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//
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#include "Bus.hpp"
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using namespace Apple::ADB;
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Bus::Bus(HalfCycles clock_speed) : half_cycles_to_microseconds_(1'000'000.0 / clock_speed.as<double>()) {}
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void Bus::run_for(HalfCycles duration) {
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time_in_state_ += duration;
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}
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size_t Bus::add_device() {
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const size_t id = next_device_id_;
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++next_device_id_;
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return id;
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}
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void Bus::set_device_output(size_t device, bool output) {
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// Modify the all-devices bus state.
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bus_state_[device] = output;
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// React to signal edges only.
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const bool data_level = get_state();
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if(data_level_ != data_level) {
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data_level_ = data_level;
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if(data_level) {
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// This was a transition to high; classify what just happened according to
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// the duration of the low period.
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const double low_microseconds = time_in_state_.as<double>() * half_cycles_to_microseconds_;
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// Low periods:
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// (partly as adapted from the AN591 data sheet; otherwise from the IIgs reference manual)
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//
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// > 1040 µs reset
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// 560–1040 µs attention
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// < 50 µs 1
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// 50–72 µs 0
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// 300 µs service request
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if(low_microseconds > 1040.0) {
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for(auto observer: observers_) {
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observer->adb_bus_did_observe_event(this, Event::Reset);
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}
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} else if(low_microseconds >= 560.0) {
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for(auto observer: observers_) {
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observer->adb_bus_did_observe_event(this, Event::Attention);
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}
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shift_register_ = 1;
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} else if(low_microseconds < 50.0) {
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shift(1);
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} else if(low_microseconds < 72.0) {
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shift(0);
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} else if(low_microseconds >= 291.0 && low_microseconds <= 309.0) {
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for(auto observer: observers_) {
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observer->adb_bus_did_observe_event(this, Event::ServiceRequest);
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}
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} else {
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for(auto observer: observers_) {
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observer->adb_bus_did_observe_event(this, Event::Unrecognised);
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}
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}
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}
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time_in_state_ = HalfCycles(0);
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}
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}
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void Bus::shift(unsigned int value) {
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shift_register_ = (shift_register_ << 1) | value;
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// Trigger a byte whenever a start bit hits bit 9.
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if(shift_register_ & 0x200) {
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for(auto observer: observers_) {
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observer->adb_bus_did_observe_event(this, Event::Byte, uint8_t(shift_register_ >> 1));
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}
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shift_register_ = 0;
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}
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}
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bool Bus::get_state() const {
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return bus_state_.all();
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}
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void Bus::add_observer(Observer *observer) {
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observers_.push_back(observer);
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}
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75
Machines/Apple/ADB/Bus.hpp
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75
Machines/Apple/ADB/Bus.hpp
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@ -0,0 +1,75 @@
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//
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// Bus.hpp
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// Clock Signal
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//
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// Created by Thomas Harte on 10/02/2021.
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// Copyright © 2021 Thomas Harte. All rights reserved.
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//
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#ifndef Bus_hpp
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#define Bus_hpp
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#include "../../../ClockReceiver/ClockReceiver.hpp"
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#include <bitset>
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#include <cstddef>
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#include <vector>
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namespace Apple {
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namespace ADB {
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/*!
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The ADB bus models the data line of the ADB bus; it allows multiple devices to
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post their current data level, or read the current level, and also offers a tokenised
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version of all activity on the bus.
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*/
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class Bus {
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public:
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Bus(HalfCycles clock_speed);
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void run_for(HalfCycles);
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size_t add_device();
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void set_device_output(size_t device, bool output);
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bool get_state() const;
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enum class Event {
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Reset,
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Attention,
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Byte,
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ServiceRequest,
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Unrecognised
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};
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struct Observer {
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/// Reports to an observer that @c event was observed in the activity
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/// observed on this bus.
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virtual void adb_bus_did_observe_event(Bus *, Event event, uint8_t value = 0xff);
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};
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/*!
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Adds an observer.
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*/
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void add_observer(Observer *);
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private:
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HalfCycles time_in_state_;
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double half_cycles_to_microseconds_ = 1.0;
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std::vector<Observer *> observers_;
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unsigned int shift_register_ = 0;
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bool data_level_ = true;
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// ADB addressing supports at most 16 devices but that doesn't include
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// the controller. So assume a maximum of 17 connected devices.
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std::bitset<17> bus_state_{0xffffffff};
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size_t next_device_id_ = 0;
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inline void shift(unsigned int);
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};
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}
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}
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#endif /* Bus_hpp */
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@ -39,7 +39,7 @@ enum class MicrocontrollerFlags: uint8_t {
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}
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GLU::GLU() : executor_(*this) {}
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GLU::GLU() : executor_(*this), bus_(HalfCycles(1'789'772)), controller_id_(bus_.add_device()) {}
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// MARK: - External interface.
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@ -168,50 +168,14 @@ void GLU::set_port_output(int port, uint8_t value) {
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// printf("Select GLU register: %d [%02x]\n", value & 0xf, value);
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register_address_ = value & 0xf;
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break;
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case 3: {
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case 3:
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// printf("IIe KWS: %d\n", (value >> 6)&3);
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// printf("ADB data line output: %d\n", (value >> 3)&1);
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// Output is inverted respective to input; the microcontroller
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// sets a value of '1' in order to pull the ADB bus low.
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const bool new_adb_level = !(value & 0x08);
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// React to signal edges only.
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if(new_adb_level != adb_level_) {
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if(new_adb_level) {
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// This was a transition to high; classify what just happened according to
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// the duration of the low period.
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const uint64_t low_microseconds = (low_period_.as<uint64_t>() * uint64_t(800000)) / uint64_t(715909);
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// Low periods:
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// (partly as adapted from the AN591 data sheet; otherwise from the IIgs reference manual)
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//
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// > 1040 µs reset
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// 560–1040 µs attention
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// < 50 µs 1
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// 50–72 µs 0
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// 300 µs service request
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printf("%llu -> ", low_microseconds);
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if(low_microseconds > 1040) {
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printf("!!! Reset\n");
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} else if(low_microseconds >= 560) {
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printf("!!! Attention\n");
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} else if(low_microseconds < 50) {
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printf("!!! bit: 1\n");
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} else if(low_microseconds < 72) {
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printf("!!! bit: 0\n");
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} else if(low_microseconds >= 291 && low_microseconds <= 309) {
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printf("!!! SRQ\n");
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} else {
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printf("!!! Rejected\n");
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}
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// TODO: eliminate total_period_ ?
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total_period_ = low_period_ = Cycles(0);
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}
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adb_level_ = new_adb_level;
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}
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} break;
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bus_.set_device_output(controller_id_, !(value & 0x08));
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break;
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default: assert(false);
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}
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@ -238,7 +202,7 @@ uint8_t GLU::get_port_input(int port) {
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return 0x06;
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case 2:
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// printf("ADB data line input, etc\n");
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return adb_level_ ? 0x80 : 0x00;
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return bus_.get_state() ? 0x80 : 0x00;
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case 3:
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// printf("ADB data line output, etc\n");
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return 0x00;
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@ -249,8 +213,5 @@ uint8_t GLU::get_port_input(int port) {
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}
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void GLU::run_ports_for(Cycles cycles) {
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total_period_ += cycles;
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if(!adb_level_) {
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low_period_ += cycles;
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}
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bus_.run_for(cycles);
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}
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@ -12,6 +12,7 @@
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#include <cstdint>
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#include <vector>
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#include "../../../InstructionSets/M50740/Executor.hpp"
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#include "../ADB/Bus.hpp"
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namespace Apple {
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namespace IIgs {
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@ -54,9 +55,10 @@ class GLU: public InstructionSet::M50740::PortHandler {
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uint8_t status_ = 0x00;
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// TODO: this should be per peripheral. But I'm putting it here for now as an exploratory step.
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bool adb_level_ = true;
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Cycles low_period_, total_period_;
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Apple::ADB::Bus bus_;
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size_t controller_id_;
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// TODO: add some other devices, and attach them to the ADB bus.
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};
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}
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@ -875,6 +875,8 @@
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4BCE005A227CFFCA000CA200 /* Macintosh.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BCE0058227CFFCA000CA200 /* Macintosh.cpp */; };
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4BCE005D227D30CC000CA200 /* MemoryPacker.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BCE005B227D30CC000CA200 /* MemoryPacker.cpp */; };
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4BCE0060227D39AB000CA200 /* Video.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BCE005E227D39AB000CA200 /* Video.cpp */; };
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4BCE1DF125D4C3FA00AE7A2B /* Bus.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BCE1DEF25D4C3FA00AE7A2B /* Bus.cpp */; };
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4BCE1DF225D4C3FA00AE7A2B /* Bus.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BCE1DEF25D4C3FA00AE7A2B /* Bus.cpp */; };
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4BCF1FA41DADC3DD0039D2E7 /* Oric.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BCF1FA21DADC3DD0039D2E7 /* Oric.cpp */; };
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4BD0FBC3233706A200148981 /* CSApplication.m in Sources */ = {isa = PBXBuildFile; fileRef = 4BD0FBC2233706A200148981 /* CSApplication.m */; };
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4BD191F52191180E0042E144 /* ScanTarget.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BD191F22191180E0042E144 /* ScanTarget.cpp */; };
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@ -1860,6 +1862,8 @@
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4BCE005C227D30CC000CA200 /* MemoryPacker.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = MemoryPacker.hpp; sourceTree = "<group>"; };
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4BCE005E227D39AB000CA200 /* Video.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = Video.cpp; sourceTree = "<group>"; };
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4BCE005F227D39AB000CA200 /* Video.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Video.hpp; sourceTree = "<group>"; };
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4BCE1DEF25D4C3FA00AE7A2B /* Bus.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = Bus.cpp; sourceTree = "<group>"; };
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4BCE1DF025D4C3FA00AE7A2B /* Bus.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = Bus.hpp; sourceTree = "<group>"; };
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4BCF1FA21DADC3DD0039D2E7 /* Oric.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = Oric.cpp; path = Oric/Oric.cpp; sourceTree = "<group>"; };
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4BCF1FA31DADC3DD0039D2E7 /* Oric.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = Oric.hpp; path = Oric/Oric.hpp; sourceTree = "<group>"; };
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4BD060A51FE49D3C006E14BE /* Speaker.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = Speaker.hpp; sourceTree = "<group>"; };
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@ -4137,8 +4141,9 @@
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4BCE0048227CE8CA000CA200 /* Apple */ = {
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isa = PBXGroup;
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children = (
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4BE2120D253FCE9C00435408 /* AppleIIgs */,
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4BCE1DEE25D4C3FA00AE7A2B /* ADB */,
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4BCE0049227CE8CA000CA200 /* AppleII */,
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4BE2120D253FCE9C00435408 /* AppleIIgs */,
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4BCE0057227CFFCA000CA200 /* Macintosh */,
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);
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path = Apple;
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@ -4179,6 +4184,15 @@
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path = Macintosh;
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sourceTree = "<group>";
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};
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4BCE1DEE25D4C3FA00AE7A2B /* ADB */ = {
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isa = PBXGroup;
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children = (
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4BCE1DEF25D4C3FA00AE7A2B /* Bus.cpp */,
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4BCE1DF025D4C3FA00AE7A2B /* Bus.hpp */,
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);
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path = ADB;
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sourceTree = "<group>";
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};
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4BCF1FA51DADC3E10039D2E7 /* Oric */ = {
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isa = PBXGroup;
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||||
children = (
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||||
|
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@ -4983,6 +4997,7 @@
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|||
files = (
|
||||
4B0E04FB1FC9FA3100F43484 /* 9918.cpp in Sources */,
|
||||
4B1B88C9202E469400B67DFF /* MultiJoystickMachine.cpp in Sources */,
|
||||
4BCE1DF225D4C3FA00AE7A2B /* Bus.cpp in Sources */,
|
||||
4B055AAA1FAE85F50060FFFF /* CPM.cpp in Sources */,
|
||||
4B055A9A1FAE85CB0060FFFF /* MFMDiskController.cpp in Sources */,
|
||||
4B0ACC3123775819008902D0 /* TIASound.cpp in Sources */,
|
||||
|
|
@ -5355,6 +5370,7 @@
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|||
4B3051301D98ACC600B4FED8 /* Plus3.cpp in Sources */,
|
||||
4B30512D1D989E2200B4FED8 /* Drive.cpp in Sources */,
|
||||
4BCE005D227D30CC000CA200 /* MemoryPacker.cpp in Sources */,
|
||||
4BCE1DF125D4C3FA00AE7A2B /* Bus.cpp in Sources */,
|
||||
4BCE0051227CE8CA000CA200 /* Video.cpp in Sources */,
|
||||
4B894536201967B4007DE474 /* Z80.cpp in Sources */,
|
||||
4BCA6CC81D9DD9F000C2D7B2 /* CommodoreROM.cpp in Sources */,
|
||||
|
|
|
|||
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