diff --git a/README.md b/README.md
index dd378ae..45ee635 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,7 @@ It scans a key matrix just like the big keyboards.
The sketch is small because the keybrd library takes care of the low-level details.
It runs the breadboard keyboard in this picture.
-
+
Example complex keybrd sketch
-----------------------------
diff --git a/tutorials/tutorial_10_writing_IOE_port_classes.md b/tutorials/tutorial_10_writing_IOE_port_classes.md
index 1f5a713..440c00f 100644
--- a/tutorials/tutorial_10_writing_IOE_port_classes.md
+++ b/tutorials/tutorial_10_writing_IOE_port_classes.md
@@ -17,8 +17,8 @@ Steps to writing a new port class:
* [SPI I/O expander example sketch](keybrd_4c_split_with_IOE/keybrd_4c_split_with_IOE.ino)
* [I2C I/O expander example sketch](../examples/keybrd_PCA9655E/keybrd_PCA9655E.ino)
5. Study other keybrd port classes.
- * SPI I/O expander port classes: PortMCP23S17 PortWrite_MCP23S17 PortRead_MCP23S17
- * I2C I/O expander port classes: PortWrite_PCA9655E PortRead_PCA9655E
+ * SPI I/O expander port classes: Port_MCP23S17
+ * I2C I/O expander port classes: Port_PCA9655E
6. Write the port classes for your I/O expander.
Debugging I/O expander code is hard because SPI or I2C protocol adds a level of indirection.
diff --git a/tutorials/tutorial_1_breadboard_keyboard.md b/tutorials/tutorial_1_breadboard_keyboard.md
index 2be0a2c..d2f9198 100644
--- a/tutorials/tutorial_1_breadboard_keyboard.md
+++ b/tutorials/tutorial_1_breadboard_keyboard.md
@@ -104,7 +104,7 @@ Breadboard keyboard assembly instructions:
![basic breadboard keyboard overhead](keybrd_1_breadboard/basic_breadboard_keyboard_overhead.JPG "basic breadboard keyboard overhead")
3. Insert jumper wires to connect Arduino pins to the matrix rows and columns.
- * [Teensy LC pinout diagram](https://www.pjrc.com/teensy/card6a_rev2.png).
+ * refer to the [Teensy LC pinout diagram](https://www.pjrc.com/teensy/card6a_rev2.png).
* row_0 is the top row, and col_0 is the left column
| Pin number | Connects to |
diff --git a/tutorials/tutorial_4b_split_keyboard_with_shift_registers.md b/tutorials/tutorial_4b_split_keyboard_with_shift_registers.md
index 85d3a91..0dc4623 100644
--- a/tutorials/tutorial_4b_split_keyboard_with_shift_registers.md
+++ b/tutorials/tutorial_4b_split_keyboard_with_shift_registers.md
@@ -33,30 +33,31 @@ Switches are connected to power (red bus) and shift register input pins (jumpers
This table lists what gets connected to the 74HC165 pins:
-```
-74HC165 left (lower half of breadboard)
-NAME PIN# DESCRIPTION TO TEENSY LC PIN# CHAIN
-SH/LD 1 shift or load input CS0 10 green wire
-CLK 2 clock input SCK0 13 yellow wire
- D4 3 parallel input
- D5 4 parallel input
- D6 5 parallel input
- D7 6 parallel input
-/QH 7 ~serial output
-GND 8 ground gnd blue bus
+**74HC165 left (lower half of breadboard)**
-74HC165 right (upper half of breadboard)
-NAME PIN# DESCRIPTION TO TEENSY LC PIN# CHAIN
-VCC 16 power pin 3.3V red wire
-CLK INH 15 clock inhibit blue bus
- D3 14 parallel input
- D2 13 parallel input
- D1 12 parallel input
- D0 11 parallel input
-SER 10 serial input blue wire to next QH
- QH 9 serial output MISO0 12 blue wire to previous SER
+|NAME |PIN#|DESCRIPTION |TO TEENSY LC PIN#|CHAIN |
+|--------|:--:|--------------------|-----------------|-----------|
+|SH/LD |1 |shift or load input |CS0 10 |green wire |
+|CLK |2 |clock input |SCK0 13 |yellow wire|
+| D4 |3 |parallel input | | |
+| D5 |4 |parallel input | | |
+| D6 |5 |parallel input | | |
+| D7 |6 |parallel input | | |
+|/QH |7 |~serial output | | |
+|GND |8 |ground |gnd |blue bus |
-```
+**74HC165 right (upper half of breadboard)**
+
+|NAME |PIN#|DESCRIPTION |TO TEENSY LC PIN#|CHAIN |
+|--------|:--:|--------------------|-----------------|-------------------------|
+|VCC |16 |power pin |3.3V |red wire |
+|CLK INH |15 |clock inhibit | |blue bus |
+| D3 |14 |parallel input | | |
+| D2 |13 |parallel input | | |
+| D1 |12 |parallel input | | |
+| D0 |11 |parallel input | | |
+|SER |10 |serial input | |blue wire to next QH |
+| QH | 9 |serial output |MISO0 12 |blue wire to previous SER|
![breadboard keyboard with shift_registers](keybrd_4b_split_keyboard_with_shift_registers/overhead.JPG )