--- nand.py-
+++ nand.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python
 
 import sys
+import time
+import select
 
 class Obj:
 	def __init__(self, parent, name, latency=None):
@@ -127,10 +129,29 @@
 		return next( ( True for a in self.que if a == t ), False )
 
 	def main_loop(self):
-		while len(self.que) > 0:
-			(tm, f, args) = self.que.pop(0)
-			self.now = tm
-			f(*args)
+		self.run = True
+		while self.run:
+			cmd_exec( sys.stdin )
+			if self.que:
+				(tm, f, args) = self.que.pop(0)
+				self.now = tm
+				f(*args)
+			else:
+				time.sleep(0.5)
+
+	def quit(self):
+		dbgout('quit')
+		self.run = False
+
+def cmd_exec(f):
+	while select.select( [f], [], [], 0 )[0]:
+		s = f.readline()
+		if not s:
+			break
+		s = s.strip()
+		if s:
+			dbgout( 'cmd_exec "{}"'.format(s) )
+			exec s
 
 def str_v(v):
 	return { True: 'H', False: 'L', None: 'Hi-Z' }.get(v, '?')
@@ -163,36 +184,6 @@
 	sched = Sched()
 
 	o = Obj(None, 'o')
-	Foo(o)
-
-	slow = Obj(o, 'slow')
-	Foo(slow, 10)
-
-	slow_12 = Obj(o, 'slow_12')
-	Foo(slow_12, 12)
-
-	o.foo.out.conn = o.slow.foo.inp
-	o.slow.foo.out.conn = o.slow_12.foo.inp
-	sched.enque( 200, o.foo.out.set, ('H',) )
-
-	NAND(o)
-	sched.enque( 300, o.nand.inp_a.set, ('L',) )
-	sched.enque( 300, o.nand.inp_b.set, ('L',) )
-	sched.enque( 320, o.nand.inp_a.set, ('H',) )
-	sched.enque( 340, o.nand.inp_b.set, ('H',) )
-	sched.enque( 360, o.nand.inp_a.set, ('L',) )
-
-	test1 = Obj(o, 'test1')
-	NAND(test1)
-	Joint(test1)
-	Lamp(test1)
-	o.test1.nand.out.conn = o.test1.jt.new_pin()
-	o.test1.jt.new_pin().conn = o.test1.nand.inp_a
-	o.test1.jt.new_pin().conn = o.test1.lamp.inp
-
-	sched.enque( 400, o.test1.nand.inp_b.set, ('H',) )
-	sched.enque( 500, o.test1.nand.inp_b.set, ('L',) )
-	sched.enque( (3,0), o.test1.lamp.inp.set, ('L',) )
 
 	sched.main_loop()