From 95d3b6e79f76582ec6bd924b265c2eec189a5130 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Mon, 28 Oct 2019 21:13:21 -0400
Subject: [PATCH] Adds a through route for the FDC interrupt line.

---
 Machines/AtariST/AtariST.cpp       | 13 +++++++++----
 Machines/AtariST/DMAController.cpp | 16 ++++++++++++++++
 Machines/AtariST/DMAController.hpp | 14 +++++++++++++-
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/Machines/AtariST/AtariST.cpp b/Machines/AtariST/AtariST.cpp
index 24d0e459d..2cd49baf2 100644
--- a/Machines/AtariST/AtariST.cpp
+++ b/Machines/AtariST/AtariST.cpp
@@ -225,7 +225,8 @@ class ConcreteMachine:
 	public CRTMachine::Machine,
 	public ClockingHint::Observer,
 	public Motorola::ACIA::ACIA::InterruptDelegate,
-	public Motorola::MFP68901::MFP68901::InterruptDelegate {
+	public Motorola::MFP68901::MFP68901::InterruptDelegate,
+	public DMAController::InterruptDelegate {
 	public:
 		ConcreteMachine(const Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
 			mc68000_(*this),
@@ -274,6 +275,7 @@ class ConcreteMachine:
 			ikbd_.set_clocking_hint_observer(this);
 
 			mfp_->set_interrupt_delegate(this);
+			dma_->set_interrupt_delegate(this);
 
 			set_gpip_input();
 		}
@@ -637,7 +639,10 @@ class ConcreteMachine:
 		}
 
 		// MARK: - GPIP input.
-		void acia6850_did_change_interrupt_status(Motorola::ACIA::ACIA *acia) final {
+		void acia6850_did_change_interrupt_status(Motorola::ACIA::ACIA *) final {
+			set_gpip_input();
+		}
+		void dma_controller_did_change_interrupt_status(DMAController *) final {
 			set_gpip_input();
 		}
 		void set_gpip_input() {
@@ -656,8 +661,8 @@ class ConcreteMachine:
 			mfp_->set_port_input(
 				0x00 |	// b7: Monochrome monitor detect (1 = is monochrome).
 				0x40 |	// b6: RS-232 ring indicator.
-				0x20 |	// b5: FD/HS interrupt (0 = interrupt requested).
-				((keyboard_acia_->get_interrupt_line() || midi_acia_->get_interrupt_line()) ? 0x0 : 0x10) |	// b4: Keyboard/MIDI interrupt (0 = interrupt requested).
+				(dma_->get_interrupt_line() ? 0x00 : 0x20) |	// b5: FD/HS interrupt (0 = interrupt requested).
+				((keyboard_acia_->get_interrupt_line() || midi_acia_->get_interrupt_line()) ? 0x00 : 0x10) |	// b4: Keyboard/MIDI interrupt (0 = interrupt requested).
 				0x08 |	// b3: Unused
 				0x04 |	// b2: RS-232 clear to send.
 				0x02 |	// b1 : RS-232 carrier detect.
diff --git a/Machines/AtariST/DMAController.cpp b/Machines/AtariST/DMAController.cpp
index 30326178f..c9d4796e9 100644
--- a/Machines/AtariST/DMAController.cpp
+++ b/Machines/AtariST/DMAController.cpp
@@ -83,3 +83,19 @@ void DMAController::run_for(HalfCycles duration) {
 	running_time_ += duration;
 	fdc_.run_for(duration.flush<Cycles>());
 }
+
+void DMAController::wd1770_did_change_output(WD::WD1770 *) {
+	const bool old_interrupt_line = interrupt_line_;
+	interrupt_line_ = fdc_.get_interrupt_request_line();
+	if(interrupt_delegate_ && interrupt_line_ != old_interrupt_line) {
+		interrupt_delegate_->dma_controller_did_change_interrupt_status(this);
+	}
+}
+
+void DMAController::set_interrupt_delegate(InterruptDelegate *delegate) {
+	interrupt_delegate_ = delegate;
+}
+
+bool DMAController::get_interrupt_line() {
+	return interrupt_line_;
+}
diff --git a/Machines/AtariST/DMAController.hpp b/Machines/AtariST/DMAController.hpp
index f082fcbc4..59cacdd3b 100644
--- a/Machines/AtariST/DMAController.hpp
+++ b/Machines/AtariST/DMAController.hpp
@@ -18,7 +18,7 @@
 namespace Atari {
 namespace ST {
 
-class DMAController {
+class DMAController: public WD::WD1770::Delegate {
 	public:
 		DMAController();
 
@@ -26,6 +26,13 @@ class DMAController {
 		void write(int address, uint16_t value);
 		void run_for(HalfCycles duration);
 
+		bool get_interrupt_line();
+
+		struct InterruptDelegate {
+			virtual void dma_controller_did_change_interrupt_status(DMAController *) = 0;
+		};
+		void set_interrupt_delegate(InterruptDelegate *delegate);
+
 	private:
 		HalfCycles running_time_;
 		struct WD1772: public WD::WD1770 {
@@ -43,10 +50,15 @@ class DMAController {
 			std::vector<std::shared_ptr<Storage::Disk::Drive>> drives_;
 		} fdc_;
 
+		void wd1770_did_change_output(WD::WD1770 *) final;
+
 		uint16_t control_ = 0;
 		uint32_t address_ = 0;
 		uint16_t status_ = 0;
 		uint16_t sector_count_ = 0;
+
+		InterruptDelegate *interrupt_delegate_ = nullptr;
+		bool interrupt_line_ = false;
 };
 
 }