Merge pull request #634 from TomHarte/OpenCrash

Resolves a potential crash at launch on the Mac

Components/DiskII/MacintoshDoubleDensityDrive.cpp

@@ -23,13 +23,14 @@ DoubleDensityDrive::DoubleDensityDrive(int input_clock_rate, bool is_800k) :
 	is_800k_(is_800k) {
 	// Start with a valid rotation speed.
 	if(is_800k) {
-		set_rotation_speed(393.3807f);
+		Drive::set_rotation_speed(393.3807f);
 	}
 }
 
 // MARK: - Speed Selection
 
 void DoubleDensityDrive::did_step(Storage::Disk::HeadPosition to_position) {
+//	printf("At track %d\n", to_position.as_int());
 	// The 800kb drive automatically selects rotation speed as a function of
 	// head position; the 400kb drive doesn't do so.
 	if(is_800k_) {
@@ -51,15 +52,23 @@ void DoubleDensityDrive::did_step(Storage::Disk::HeadPosition to_position) {
 		*/
 		const int zone = to_position.as_int() >> 4;
 		switch(zone) {
-			case 0:		set_rotation_speed(393.3807f);	break;
-			case 1:		set_rotation_speed(429.1723f);	break;
-			case 2:		set_rotation_speed(472.1435f);	break;
-			case 3:		set_rotation_speed(524.5672f);	break;
-			default:	set_rotation_speed(590.1098f);	break;
+			case 0:		Drive::set_rotation_speed(393.3807f);	break;
+			case 1:		Drive::set_rotation_speed(429.1723f);	break;
+			case 2:		Drive::set_rotation_speed(472.1435f);	break;
+			case 3:		Drive::set_rotation_speed(524.5672f);	break;
+			default:	Drive::set_rotation_speed(590.1098f);	break;
 		}
 	}
 }
 
+void DoubleDensityDrive::set_rotation_speed(float revolutions_per_minute) {
+	if(!is_800k_) {
+		// Don't allow drive speeds to drop below 10 RPM, as a temporary sop
+		// to sanity.
+		Drive::set_rotation_speed(std::max(10.0f, revolutions_per_minute));
+	}
+}
+
 // MARK: - Control input/output.
 
 void DoubleDensityDrive::set_enabled(bool) {

Components/DiskII/MacintoshDoubleDensityDrive.hpp

@@ -18,6 +18,20 @@ class DoubleDensityDrive: public IWMDrive {
 	public:
 		DoubleDensityDrive(int input_clock_rate, bool is_800k);
 
+		/*!
+			@returns @c true if this is an 800kb drive; @c false otherwise.
+		*/
+		bool is_800k() {
+			return is_800k_;
+		}
+
+		/*!
+			Sets the current rotation speed of this drive only if it is a 400kb drive.
+			800kb drives select their own rotation speed based on head position,
+			and ignore this input.
+		*/
+		void set_rotation_speed(float revolutions_per_minute);
+
 		void set_enabled(bool) override;
 		void set_control_lines(int) override;
 		bool read() override;

Machines/Apple/Macintosh/DriveSpeedAccumulator.cpp

@@ -11,6 +11,8 @@
 using namespace Apple::Macintosh;
 
 void DriveSpeedAccumulator::post_sample(uint8_t sample) {
+	if(!number_of_drives_) return;
+
 	// An Euler-esque approximation is used here: just collect all
 	// the samples until there is a certain small quantity of them,
 	// then produce a new estimate of rotation speed and start the
@@ -20,9 +22,31 @@ void DriveSpeedAccumulator::post_sample(uint8_t sample) {
 
 	if(sample_pointer_ == samples_.size()) {
 		sample_pointer_ = 0;
-//		for(int c = 0; c < 512; c += 32) {
-//			printf("%u ", samples_[c]);
-//		}
-//		printf("\n");
+
+		// Treat 33 as a zero point and count zero crossings; then approximate
+		// the RPM from the frequency of those.
+		int samples_over = 0;
+		int sum = 0;
+		const uint8_t centre = 33;
+		for(size_t c = 0; c < 512; ++c) {
+			if(samples_[c] > centre) ++ samples_over;
+			sum += samples_[c];
+		}
+
+		// TODO: if the above is the correct test, do it on sample receipt rather than
+		// bothering with an intermediate buffer.
+
+		// The below fits for a function like `a + bc`.
+		const float rotation_speed = (float(sum) * 0.052896440564137f) - 259.0f;
+
+		for(int c = 0; c < number_of_drives_; ++c) {
+			drives_[c]->set_rotation_speed(rotation_speed);
+		}
+//		printf("RPM: %0.2f (%d over; %d sum)\n", rotation_speed, samples_over, sum);
 	}
 }
+
+void DriveSpeedAccumulator::add_drive(Apple::Macintosh::DoubleDensityDrive *drive) {
+	drives_[number_of_drives_] = drive;
+	++number_of_drives_;
+}

Machines/Apple/Macintosh/DriveSpeedAccumulator.hpp

@@ -13,6 +13,8 @@
 #include <cstddef>
 #include <cstdint>
 
+#include "../../../Components/DiskII/MacintoshDoubleDensityDrive.hpp"
+
 namespace Apple {
 namespace Macintosh {
 
@@ -23,9 +25,18 @@ class DriveSpeedAccumulator {
 		*/
 		void post_sample(uint8_t sample);
 
+		/*!
+			Adds a connected drive. Up to two of these
+			can be supplied. Only Macintosh DoubleDensityDrives
+			are supported.
+		*/
+		void add_drive(Apple::Macintosh::DoubleDensityDrive *drive);
+
 	private:
 		std::array<uint8_t, 512> samples_;
 		std::size_t sample_pointer_ = 0;
+		Apple::Macintosh::DoubleDensityDrive *drives_[2] = {nullptr, nullptr};
+		int number_of_drives_ = 0;
 };
 
 }

Machines/Apple/Macintosh/Macintosh.cpp

@@ -116,6 +116,10 @@ template <Analyser::Static::Macintosh::Target::Model model> class ConcreteMachin
 			iwm_.iwm.set_drive(0, &drives_[0]);
 			iwm_.iwm.set_drive(1, &drives_[1]);
 
+			// If they are 400kb drives, also attach them to the drive-speed accumulator.
+			if(!drives_[0].is_800k()) drive_speed_accumulator_.add_drive(&drives_[0]);
+			if(!drives_[1].is_800k()) drive_speed_accumulator_.add_drive(&drives_[1]);
+
 			// Make sure interrupt changes from the SCC are observed.
 			scc_.set_delegate(this);
 

OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift

@@ -56,7 +56,16 @@ class MachineDocument:
 	override func windowControllerDidLoadNib(_ aController: NSWindowController) {
 		super.windowControllerDidLoadNib(aController)
 		aController.window?.contentAspectRatio = self.aspectRatio()
-		setupMachineOutput()
+		if self.machine != nil {
+			setupMachineOutput()
+		} else {
+			// This is somewhat of a desperate workaround; just having loaded the Nib doesn't
+			// mean that the window is visible yet, but presenting the ROM import sheet before
+			// the window is visible will result in it being free floating.
+			DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + .milliseconds(500)) {
+				self.configureAs(self.selectedMachine!)
+			}
+		}
 	}
 
 	// Attempting to show a sheet before the window is visible (such as when the NIB is loaded) results in
@@ -340,6 +349,11 @@ class MachineDocument:
 	@IBOutlet var romReceiverView: CSROMReceiverView?
 	private var romRequestBaseText = ""
 	func requestRoms() {
+		// Don't act yet if there's no window controller yet.
+		if self.windowControllers.count == 0 {
+			return
+		}
+
 		// Load the ROM requester dialogue.
 		Bundle.main.loadNibNamed("ROMRequester", owner: self, topLevelObjects: nil)
 		self.romReceiverView!.delegate = self