diff --git a/doc/keybrd_library_developer_guide.md b/doc/keybrd_library_developer_guide.md
index 64ef360..9991e63 100644
--- a/doc/keybrd_library_developer_guide.md
+++ b/doc/keybrd_library_developer_guide.md
@@ -160,12 +160,14 @@ Following the style guide makes it easier for the next programmer to understand
   <!-- http://stackoverflow.com/questions/2198241/best-practice-for-c-function-commenting -->
 
 ## Trace of keybrd scan
-Arduino does not have a debugger; so here is a list of functions in the order that they are called.
+Arduino does not have a debugger.
+So here is the next best thing; a list of functions in the order that they are called.
 Refer to it like a table of contents while reading the keybrd library.
 
 ```
     Matrix::scan()                          for each row
         Row::process()
+            Row::wait()
             Row::scan()
                 RowPort_*::setActivePin*()      strobe row on
                                                 for each col port
@@ -177,6 +179,9 @@ Refer to it like a table of contents while reading the keybrd library.
                                                             set rowState bit
             Row::debounce()                     debounce
             Row::pressRelease()                 for each key in row
+                                                    if falling edge
+                Key_*::release()                        scanCode->release()
+                    Code_*::release()                       Keyboard.release(scancode)
                                                     if rising edge
                 Key_*::press()                          scanCode->press()
                     Code_*::press()                         Keyboard.press(scancode)
diff --git a/src/ColPort.cpp b/src/ColPort.cpp
index 015406e..6fc72bf 100644
--- a/src/ColPort.cpp
+++ b/src/ColPort.cpp
@@ -7,5 +7,7 @@ uint8_t ColPort::getColPins()
 
 uint8_t ColPort::getPortState()
 {
+//todo Keyboard.print(" portState=");
+//Keyboard.print(portState);
     return portState;
 }
diff --git a/src/getFreeSRAM.h b/src/getFreeSRAM.h
index f97fad9..23094df 100644
--- a/src/getFreeSRAM.h
+++ b/src/getFreeSRAM.h
@@ -20,6 +20,7 @@ extern unsigned int __heap_start;
 extern void *__brkval;
 
 //measure and return amount of free SRAM
+/*
 uint16_t getFreeSRAM()
 {
     uint8_t newVariable;
@@ -34,3 +35,19 @@ uint16_t getFreeSRAM()
         return (((uint16_t)&newVariable) - ((uint16_t)__brkval));
     }
 };
+*/
+// uint32_t for Teensy LC
+uint32_t getFreeSRAM()
+{
+    uint8_t newVariable;
+    // if heap is empty, use bss as start memory address
+    if ((uint32_t)__brkval == 0)
+    {
+        return (((uint32_t)&newVariable) - ((uint32_t)&__bss_end));
+    }
+    // else use heap end as the start of the memory address
+    else
+    {
+        return (((uint32_t)&newVariable) - ((uint32_t)__brkval));
+    }
+};
diff --git a/tutorials/keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino b/tutorials/keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino
index a1ff540..422dc0b 100644
--- a/tutorials/keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino
+++ b/tutorials/keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino
@@ -24,7 +24,6 @@ keybrd runs at the end of this sketch, under the "MAIN" heading.
 // ################## GLOBAL ###################
 // ================= INCLUDES ==================
 /*
-The compiler copies #included files into the sketch.
 All the includes in this sketch are to keybrd library classes.
 */
 //Ports
diff --git a/tutorials/tutorial_1_breadboard_keyboard.md b/tutorials/tutorial_1_breadboard_keyboard.md
index ac968ae..76a37ad 100644
--- a/tutorials/tutorial_1_breadboard_keyboard.md
+++ b/tutorials/tutorial_1_breadboard_keyboard.md
@@ -49,17 +49,24 @@ Switch-diode pairs connect rows to columns.
 The green rectangle on the right is the Teensy 2.0 microcontroller.
 The matrix rows and columns connect to the microcontroller via jumper wires.
 
+Tutorials 4,5,9 will add more components to the breadboard.
+Positioning components as shown on the picture will provide space for those components, with room for up to 9 cols.
+Breadboard terminal strips are indexed 1 to 63 for accurate positioning of components.
+    [pic of IOE, LEDs, active high on one bb]
+
 Breadboard keyboard assembly instructions:
 
 1. Cut leads to length.
  * tactile-switch-lead length 6 to 8 mm
  * diodes 22 to 24 mm total end-to-end length, and save the cut offs for steps 2 and 3
 2. Insert parts into the breadboard as shown in the picture.
+ * Teensy LC on the terminal strip labeled 1
+ * switch leads oriented so that they will connect diodes to columns
  * diode cut offs connect terminal strips into columns
  * diodes are orient with cathode (banded end) towards the row (power strip)
- * switches connect diode to columns
 3. Insert jumper wires connecting Teensy2 to the matrix rows and columns.
  * follow pin connections table (below) and consult pinout diagram in
+   [close-up pic shows switch way half out, to show lead orientation]
    [Teensy2_pinout.txt](../doc/Teensy2_pinout.txt)
 
 todo add a schematic
diff --git a/tutorials/tutorial_2_single-layer_keyboard.md b/tutorials/tutorial_2_single-layer_keyboard.md
index 417b980..68f7219 100644
--- a/tutorials/tutorial_2_single-layer_keyboard.md
+++ b/tutorials/tutorial_2_single-layer_keyboard.md
@@ -1,12 +1,13 @@
 Tutorial 2 - single-layer keyboard
 =======================================
-[keybrd_2_single-layer_annotated.ino](keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino) explains how a keybrd sketch works.
-You can view the class definitions in the [keybrd library](../src/).
-
+The easiest way to learn the keyboard library is to read some simple sketches.
+[keybrd_2_single-layer_annotated.ino](keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino) is a simple sketch with annotations that explain how a keybrd sketch works.
 After reading the sketch you will be able to modify it to suite your own single-layer keyboard design.
 
+You can view the class definitions in the [keybrd library](../src/).
+
 ## Exercises
-1) Add a third column to the breadboard and sketch.
+1) Add a third column to the breadboard keyboard and sketch.
 
 | Layout | **0** | **1** | **2** |
 |:------:|-------|-------|-------|