Add workaround for encoding errors in $F001 handler. Closes #29

CHANGES.txt

@@ -1,5 +1,9 @@
 0.23-dev (Next Release)
 
+ - Added a workaround to $F001 output to catch encoding errors and
+   display a "?" instead of crashing.  This condition can occur if
+   the 6502 program sends bytes to $F001 that aren't compatible with
+   the terminal's character encoding.
 
 0.22 (2015-02-09)
 

py65/monitor.py

@@ -202,7 +202,10 @@ class Monitor(cmd.Cmd):
 
     def _install_mpu_observers(self):
         def putc(address, value):
-            self.stdout.write(chr(value))
+            try:
+                self.stdout.write(chr(value))
+            except UnicodeEncodeError: # Python 3
+                self.stdout.write("?")
             self.stdout.flush()
 
         def getc(address):