diff --git a/src/PortRead_PCA9655E.cpp b/src/PortRead_PCA9655E.cpp
index 9d4ddeb..cb210b6 100644
--- a/src/PortRead_PCA9655E.cpp
+++ b/src/PortRead_PCA9655E.cpp
@@ -1,17 +1,9 @@
 #include "PortRead_PCA9655E.h"
 
-/*
-configures column port's configuration, input, and pins.
-*/
-PortRead_PCA9655E::PortRead_PCA9655E (PortIOE& port, const uint8_t readPins)
-    :  port(port), readPins(readPins),
-      configurationByteCommand(port.num + 6), inputByteCommand(port.num)
-{}
-
 void PortRead_PCA9655E::begin()
 {
     Wire.beginTransmission(port.DEVICE_ADDR);
-    Wire.write(configurationByteCommand);
+    Wire.write(port.num + 6);                   //configuration byte command
     Wire.write(readPins);    //0=configure as output (for LED), 1=configure as input (for read)
     Wire.endTransmission();
 }
@@ -22,10 +14,10 @@ returns port value
 uint8_t PortRead_PCA9655E::read()
 {
     Wire.beginTransmission(port.DEVICE_ADDR);
-    Wire.write(inputByteCommand);               //input immediately before requestFrom
+    Wire.write(port.num);                       //input byte command
     Wire.endTransmission(false);                //PCA9655E needs false to send a restart
 
-    Wire.requestFrom(port.DEVICE_ADDR, 1u);            //request one byte from input port
+    Wire.requestFrom(port.DEVICE_ADDR, 1u);     //request one byte from input port
 
     return Wire.read();
 }
diff --git a/src/PortRead_PCA9655E.h b/src/PortRead_PCA9655E.h
index b35eb82..836a680 100644
--- a/src/PortRead_PCA9655E.h
+++ b/src/PortRead_PCA9655E.h
@@ -30,11 +30,9 @@ class PortRead_PCA9655E : public PortReadInterface
     private:
         PortIOE& port;
         const uint8_t readPins;                  //bitwise pin configuration, 1 means read pin
-        const uint8_t configurationByteCommand;
-        const uint8_t inputByteCommand;
     public:
-        //The constructor initialization list is in .cpp
-        PortRead_PCA9655E(PortIOE& port, const uint8_t readPins);
+        PortRead_PCA9655E (PortIOE& port, const uint8_t readPins)
+            : port(port), readPins(readPins) {}
         void begin();
         virtual uint8_t read();
 };
diff --git a/src/PortWrite_MCP23S17.h b/src/PortWrite_MCP23S17.h
index 1e7c973..e09e2f9 100644
--- a/src/PortWrite_MCP23S17.h
+++ b/src/PortWrite_MCP23S17.h
@@ -31,6 +31,8 @@ Diode orientation is explained in keybrd_library_user_guide.md > Diode orientati
 MCP23S17 data sheet
  ----------------
  http://www.onsemi.com/pub_link/Collateral/MCP23S17-D.PDF
+
+WARNING: This class hardcodes Slave Select to Arduino Pin 10 to avoid the speed penalty of digitalWrite
 */
 
 class PortWrite_MCP23S17 : public PortWriteInterface
diff --git a/src/PortWrite_PCA9655E.cpp b/src/PortWrite_PCA9655E.cpp
index 2e1677f..4ed9aef 100644
--- a/src/PortWrite_PCA9655E.cpp
+++ b/src/PortWrite_PCA9655E.cpp
@@ -1,11 +1,5 @@
 #include "PortWrite_PCA9655E.h"
 
-/*
-configures column port's configuration and output.
-*/
-PortWrite_PCA9655E::PortWrite_PCA9655E(PortIOE& port)
-    : port(port), configurationByteCommand(port.num + 6), outputByteCommand(port.num + 2) {}
-
 /*
 If PortRead_PCA9655E is instantiated on the same port, do NOT use PortWrite_PCA9655E::begin().
 Otherwise readPins could be overwritten.
@@ -13,7 +7,7 @@ Otherwise readPins could be overwritten.
 void PortWrite_PCA9655E::begin()
 {
     Wire.beginTransmission(port.DEVICE_ADDR);
-    Wire.write(configurationByteCommand);
+    Wire.write(port.num + 6);                   //configuration byte command
     Wire.write(0);                              //0=configure as output (for strobe pins and LED)
     Wire.endTransmission();
 }
@@ -36,7 +30,7 @@ void PortWrite_PCA9655E::write(const uint8_t pin, const bool value)
     }
 
     Wire.beginTransmission(port.DEVICE_ADDR);
-    Wire.write(outputByteCommand);
+    Wire.write(port.num + 2);                   //output Byte command
     Wire.write(port.outputVal);
     Wire.endTransmission();
 }
diff --git a/src/PortWrite_PCA9655E.h b/src/PortWrite_PCA9655E.h
index 200c3af..ce797e6 100644
--- a/src/PortWrite_PCA9655E.h
+++ b/src/PortWrite_PCA9655E.h
@@ -37,12 +37,8 @@ class PortWrite_PCA9655E : public PortWriteInterface
 {
     private:
         PortIOE& port;
-        const uint8_t configurationByteCommand;
-        const uint8_t outputByteCommand;
-
     public:
-        //The constructor initialization list is in .cpp
-        PortWrite_PCA9655E(PortIOE& port);
+        PortWrite_PCA9655E(PortIOE& port) : port(port) {}
         void begin();
 
         virtual void write(const uint8_t pin, const bool level);