diff -r 9e2addbb9674 -r 254d5d1bc659 c++/lpt-signal-generator/lpt.cpp
--- a/c++/lpt-signal-generator/lpt.cpp	Fri Jun 09 23:23:25 2017 +0200
+++ b/c++/lpt-signal-generator/lpt.cpp	Sun Jun 11 01:25:56 2017 +0200
@@ -56,7 +56,7 @@
 
   int addr = 0xe400; // parallel port address; first number of given port in: cat /proc/ioports | grep parport
   int baseFreq = 10000; // base frequency in Hz, should be between 5 000 between 10 000 Hz; lower frequency leads to dashed/dotted lines instead of greyscale
-  int outputPower = 10; // duty cycle; 100 = 100 %
+  int outputPower = 20; // duty cycle; 100 = 100 %
   int duration = 1; // in seconds; total sleep time, see note above
 
   int valueWidth =  10; // just for padding of printed values
@@ -74,6 +74,9 @@
   int timeOn =  oneSecond *        outputPower  / 100 / baseFreq;
   int timeOff = oneSecond * (100 - outputPower) / 100 / baseFreq;
 
+  timeOn  -= 13;
+  timeOff -= 13;
+
   int cycleCount = duration * baseFreq;
   wprintf(L"%*ls %'*d ×\n", labelWidth, L"Cycle count:", valueWidth, cycleCount);
   wprintf(L"%*ls %'*d μs 1× in each cycle\n", labelWidth, L"Time on:",  valueWidth, timeOn);