- Fixed two memory state machine issues:

1) The Orbit microcode occasionally expects to be able to do a double-word read in cycles 6 and 7 instead of the usual 5 and 6.
  2) The double-word logic incorrectly handles several species of overlapped read/writes, which Spruce's layout microcode uses.

As a result, Spruce now works, as do the Smalltalk-80 images.

Several tweaks to microcode disassembly (still rough).

Completed Orbit / Dover ROS / Dover Print Engine emulation.  Still some rough edges; it works and can create PDF output.

Tweaked Disk Controller's Restore operation, it is now more accurate though wasn't causing any noticable issues.

Contralto/AltoSystem.cs

@@ -242,8 +242,6 @@ namespace Contralto
             get { return _scheduler; }
         }
 
-        public int _novaInst;        
-
         private AltoCPU _cpu;
         private MemoryBus _memBus;
         private Memory.Memory _mem;