diff --git a/pymlac/MainCPU.py b/pymlac/MainCPU.py
index 8919dbc..8a1cb02 100644
--- a/pymlac/MainCPU.py
+++ b/pymlac/MainCPU.py
@@ -10,6 +10,10 @@ import sys
 from Globals import *
 import Trace
 
+import log
+log = log.Log('test.log', log.Log.DEBUG)
+
+
 trace = Trace.Trace(TRACE_FILENAME)
 
 class MainCPU(object):
@@ -229,7 +233,8 @@ class MainCPU(object):
         eff_address = self.memory.eff_address(address, indirect)
         self.memory.put(self.AC, eff_address, False)
         tracestr = trace.itrace(self.dot, 'DAC', indirect, address)
-        print('DAC: storing %06o at address %06o' % (self.AC, eff_address))
+        log('DAC: %s' % tracestr)
+        log('DAC: storing %06o at address %06o' % (self.AC, eff_address))
         return (3, tracestr) if indirect else (2, tracestr)
 
     def i_XAM(self, indirect, address, instruction):
diff --git a/pymlac/Memory.py b/pymlac/Memory.py
index 96d966c..9d31d6b 100644
--- a/pymlac/Memory.py
+++ b/pymlac/Memory.py
@@ -10,6 +10,10 @@ import struct
 from Globals import *
 import Trace
 
+import log
+log = log.Log('test.log', log.Log.DEBUG)
+
+
 
 class Memory(object):
 
diff --git a/pymlac/TtyIn.py b/pymlac/TtyIn.py
index 48ecc62..dbdb774 100644
--- a/pymlac/TtyIn.py
+++ b/pymlac/TtyIn.py
@@ -7,7 +7,7 @@ Emulate the Input TTY device (TTYIN).
 from Globals import *
 
 import log
-log = log.Log('test_TTYIN.log', log.Log.DEBUG)
+log = log.Log('test.log', log.Log.DEBUG)
 
 
 class TtyIn(object):
@@ -27,7 +27,7 @@ class TtyIn(object):
 
         self.filename = None
         self.open_file = None
-        self.value = 0
+        self.value = 0xff
         self.atEOF = True
         self.cycle_count = 0
         self.status = self.DEVICE_NOT_READY
@@ -49,10 +49,13 @@ class TtyIn(object):
             # EOF on input file
             self.atEOF = True
             self.cycle_count = 0
-            self.value = 0
             log('TTYIN: EOF set on device (file %s)' % self.fname)
-        self.value = ord(self.value)
-        self.offset = -1
+        else:
+            self.value = ord(self.value)
+        self.offset = 0
+
+        log('TTYIN: Mounting file %s, .value=%03o, .offset=%04o'
+            % (self.filename, self.value, self.offset))
 
     def dismount(self):
         """Dismount the file on the TTYIN device."""
@@ -66,7 +69,7 @@ class TtyIn(object):
         self.value = 0
         self.atEOF = True
         self.status = self.DEVICE_NOT_READY
-        self.offset = None
+        self.offset = 0
 
     def read(self):
         """Return the current device value."""
@@ -86,7 +89,7 @@ class TtyIn(object):
     def clear(self):
         """Clear the device 'ready' status."""
 
-        log("TTYIN: Clearing device 'ready' status")
+        log("TTYIN: Clearing device 'ready' status, offset=%04o" % self.offset)
 
         self.status = self.DEVICE_NOT_READY
 
@@ -101,15 +104,15 @@ class TtyIn(object):
                 self.cycle_count += self.DEVICE_READY_CYCLES
                 self.status = self.DEVICE_READY
                 self.value = self.open_file.read(1)
+                self.offset += 1
                 if len(self.value) < 1:
                     # EOF on input file
                     self.atEOF = True
-                    self.value = chr(0)
+                    self.value = chr(0xff)
                     self.cycle_count = 0
                     self.status = self.DEVICE_NOT_READY
                     log('TTYIN: EOF set on device (file %s)' % self.filename)
-                else:
-                    log('TTYIN: .cycle_count expired, new character is %s (%03o)'
-                            % (self.value, ord(self.value[0])))
                 self.value = ord(self.value)
-                self.offset += 1
+
+                log('TTYIN: .cycle_count expired, new character is %03o, .offset=%04o'
+                        % (self.value, self.offset))
diff --git a/pymlac/pymlac b/pymlac/pymlac
index 1fbec2c..dc26319 100755
--- a/pymlac/pymlac
+++ b/pymlac/pymlac
@@ -46,6 +46,9 @@ import TtyIn
 import TtyOut
 import Trace
 
+import log
+log = log.Log('test.log', log.Log.DEBUG)
+
 trace = Trace.Trace(TRACE_FILENAME)
 
 
@@ -85,8 +88,9 @@ def start_running(cpu, memory, ptrptp, ttyin):
         (cycles, tracestr) = cpu.execute_one_instruction()
         if tracestr:
             endstr = trace.itraceend(False)
-            trace.comment('%s\t%s' % (tracestr, endstr))
-            trace.flush()
+            log('%s\t%s' % (tracestr, endstr))
+#            trace.comment('%s\t%s' % (tracestr, endstr))
+#            trace.flush()
         ptrptp.ptr_tick(cycles)
         ptrptp.ptp_tick(cycles)
         ttyin.tick(cycles)
@@ -202,7 +206,7 @@ def main():
                 for rng in r.split(':'):
                     be = rng.split(',')
                     if len(be) != 2:
-                        usage("'-r' ranges must have form 'begin,end'")
+                        usage("'-t' ranges must have form 'begin,end'")
                         sys.exit(10)
                     (begin, end) = be
                     begin = str2int(begin)