Merge pull request #1627 from TomHarte/TubeReset

Propagate system reset to the tube.

Machines/Acorn/BBCMicro/BBCMicro.cpp

@@ -1091,7 +1091,7 @@ private:
 			break;
 
 			case Key::Break:
-				m6502_.template set<CPU::MOS6502Mk2::Line::Reset>(is_pressed);
+				set_reset(is_pressed);
 			break;
 
 			default:
@@ -1102,10 +1102,18 @@ private:
 	bool was_caps_ = false;
 
 	void clear_all_keys() final {
-		m6502_.template set<CPU::MOS6502Mk2::Line::Reset>(false);
+		set_reset(false);
 		system_via_port_handler_.clear_all_keys();
 	}
 
+	void set_reset(const bool reset) {
+		m6502_.template set<CPU::MOS6502Mk2::Line::Reset>(reset);
+		if constexpr (tube_processor != TubeProcessor::None) {
+			tube_.ula.set_reset(reset);
+			tube_.processor.set_reset(reset);
+		}
+	}
+
 	HalfCycles get_typer_delay(const std::string &text) const final {
 		if(!m6502_.is_resetting()) {
 			return Cycles(0);

Machines/Acorn/Tube/FIFO.hpp

@@ -45,6 +45,11 @@ struct FIFO {
 		return result;
 	}
 
+	/// Empties the FIFO.
+	void reset() {
+		read_ = write_ = 0;
+	}
+
 private:
 	ULAT &ula_;
 	uint8_t mask_;

Machines/Acorn/Tube/Tube6502.hpp

@@ -60,6 +60,7 @@ public:
 	void set_reset(const bool reset) {
 		m6502_.template set<CPU::MOS6502Mk2::Line::Reset>(reset);
 		rom_visible_ |= reset;
+		update_interrupts();
 	}
 
 private:

Machines/Acorn/Tube/TubeZ80.hpp

@@ -36,6 +36,7 @@ public:
 	void set_reset(const bool reset) {
 		z80_.set_reset_line(reset);
 		rom_visible_ |= reset;
+		update_interrupts();
 	}
 
 	HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {

Machines/Acorn/Tube/ULA.hpp

@@ -113,6 +113,21 @@ struct ULA {
 			default: __builtin_unreachable();
 		}
 	}
+
+	void set_reset(const bool reset) {
+		if(reset) {
+			flags_ = 0x01;
+			to_parasite1_.reset();
+			to_parasite2_.reset();
+			to_parasite3_.reset();
+			to_parasite4_.reset();
+			to_host1_.reset();
+			to_host2_.reset();
+			to_host3_.reset();
+			to_host4_.reset();
+		}
+	}
+
 private:
 	uint8_t status() const {
 		return flags_;