Add keyboard command lookaside; dummy IDE read.

Machines/PCCompatible/KeyboardController.hpp

@@ -431,9 +431,9 @@ private:
 
 		void perform(const uint8_t command) {
 			switch(command) {
-//				case 0xf2:
-//					controller_.post_keyboard({0xfa});
-//				break;
+				case 0xf2:
+					controller_.post_keyboard({0xfa});
+				break;
 
 				case 0xff:
 					controller_.post_keyboard({0xfa, 0xaa});

Machines/PCCompatible/PCCompatible.cpp

@@ -496,6 +496,10 @@ public:
 				case 0x03fc:	case 0x03fd:	case 0x03fe:	case 0x03ff:
 					// Ignore serial port accesses.
 				break;
+
+				// IDE.
+				case 0x01f7:
+				return 0;
 			}
 			return 0xff;
 		}