adding flags for CTS-DSR hack and "safe" flow control

apple410/__init__.py

@@ -11,19 +11,28 @@ def plot_to_svg(instream, outstream):
 
 class Apple410:
     """A simple class for queing up commands for the Apple 410"""
-    def __init__(self, portname, baud=9600):
-        self.serial = serial.Serial(portname, baud, rtscts=True, dsrdtr=True, timeout=0.1)
+    def __init__(self, portname, baud=9600, flow_control_safe=False, cts_hack=False):
+        self.serial = serial.Serial(portname, baud, rtscts=False, dsrdtr=True, timeout=0.1)
         self.pos = (0,0)
         self.wd = self.vp = (0,0,2394,1759)
+        self.flow_control_safe = flow_control_safe
+        self.cts_hack = cts_hack
 
     def sendchar(self, c):
-        self.serial.flush()
-        while not self.serial.cts:
-            time.sleep(0.2)
-        while not self.serial.dsr:
-            time.sleep(0.2)
-        self.serial.write(c.encode('ascii'))
-        self.serial.flush()
+        if self.flow_control_safe:
+            self.serial.write(c.encode('ascii'))
+        elif self.cts_hack:
+            self.serial.flush()
+            while not self.serial.cts:
+                time.sleep(0.2)
+            self.serial.write(c.encode('ascii'))
+            self.serial.flush()
+        else:
+            self.serial.flush()
+            while not self.serial.dsr:
+                time.sleep(0.2)
+            self.serial.write(c.encode('ascii'))
+            self.serial.flush()
         
     def send(self, command):
         for c in command: