added missing write method to QuadTari (fixes #832, SaveKey not working in QT)

src/emucore/QuadTari.cxx

@@ -107,6 +107,19 @@ unique_ptr<Controller> QuadTari::addController(const Controller::Type type, bool
   }
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool QuadTari::isFirst()
+{
+  constexpr int MIN_CYCLES = 76; // minimal cycles required for stable input switch (just to be safe)
+
+  if(mySystem.tia().dumpPortsCycles() < MIN_CYCLES)
+    // Random controller if read too soon after dump ports changed
+    return mySystem.randGenerator().next() % 2;
+  else
+    // If bit 7 of VBlank is not set, read first, else second controller
+    return !(mySystem.tia().registerValue(VBLANK) & 0x80);
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool QuadTari::read(DigitalPin pin)
 {
@@ -114,22 +127,21 @@ bool QuadTari::read(DigitalPin pin)
   // can switch the controller multiple times per frame
   // (we can't just read 60 times per second in the ::update() method)
 
-  constexpr int MIN_CYCLES = 76; // minimal cycles required for stable input switch (just to be safe)
+  if(isFirst())
-  bool readFirst;
-
-  if(mySystem.tia().dumpPortsCycles() < MIN_CYCLES)
-    // Random controller if read too soon after dump ports changed
-    readFirst = mySystem.randGenerator().next() % 2;
-  else
-    // If bit 7 of VBlank is not set, read first, else second controller
-    readFirst = !(mySystem.tia().registerValue(VBLANK) & 0x80);
-
-  if(readFirst)
     return myFirstController->read(pin);
   else
     return mySecondController->read(pin);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void QuadTari::write(DigitalPin pin, bool value)
+{
+  if(isFirst())
+    return myFirstController->write(pin, value);
+  else
+    return mySecondController->write(pin, value);
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void QuadTari::update()
 {

src/emucore/QuadTari.hxx

@@ -59,6 +59,16 @@ class QuadTari : public Controller
     */
     bool read(DigitalPin pin) override;
 
+    /**
+      Write the given value to the specified digital pin for this
+      controller.  Writing is only allowed to the pins associated
+      with the PIA.  Therefore you cannot write to pin six.
+
+      @param pin The pin of the controller jack to write to
+      @param value The value to write to the pin
+    */
+    void write(DigitalPin pin, bool value) override;
+
     /**
       Update the entire digital and analog pin state according to the
       events currently set.
@@ -96,6 +106,9 @@ class QuadTari : public Controller
       Controller::Type xtype, int xid, Controller::Type ytype, int yid) override;
 
   private:
+    // determine which controller is active
+    bool isFirst();
+
     unique_ptr<Controller> addController(const Controller::Type type, bool second);
 
     const OSystem& myOSystem;