diff --git a/RaspberryPi/apple2driver/a2io/communication.go b/RaspberryPi/apple2driver/a2io/communication.go
index bfb3118..3badabc 100644
--- a/RaspberryPi/apple2driver/a2io/communication.go
+++ b/RaspberryPi/apple2driver/a2io/communication.go
@@ -1,3 +1,10 @@
+// Copyright Terence J. Boldt (c)2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file defines the interface for communicating with the Apple II via
+// the Raspberry Pi GPIO ports but can also be mocked out for tests or
+// passed input to the user for interactive testing
 package a2io
 
 type A2Io interface {
diff --git a/RaspberryPi/apple2driver/a2io/gpio.go b/RaspberryPi/apple2driver/a2io/gpio.go
index d0fed12..ae0a959 100644
--- a/RaspberryPi/apple2driver/a2io/gpio.go
+++ b/RaspberryPi/apple2driver/a2io/gpio.go
@@ -1,3 +1,9 @@
+// Copyright Terence J. Boldt (c)2020-2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is used for communicating with the Apple II data bus via the
+// GPIO ports on the Raspberry Pi
 package a2io
 
 import (
diff --git a/RaspberryPi/apple2driver/a2io/mockio.go b/RaspberryPi/apple2driver/a2io/mockio.go
index 0b93ee4..25ac3f7 100644
--- a/RaspberryPi/apple2driver/a2io/mockio.go
+++ b/RaspberryPi/apple2driver/a2io/mockio.go
@@ -1,3 +1,9 @@
+// Copyright Terence J. Boldt (c)2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is used for mocking the GPIO code so that unit tests can be run
+// on any machine and not just a Raspberry Pi
 package a2io
 
 import (
diff --git a/RaspberryPi/apple2driver/a2io/userio.go b/RaspberryPi/apple2driver/a2io/userio.go
new file mode 100644
index 0000000..589f15c
--- /dev/null
+++ b/RaspberryPi/apple2driver/a2io/userio.go
@@ -0,0 +1,69 @@
+// Copyright Terence J. Boldt (c)2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is only used during development for interactive testing of the
+// driver code. Simply replace `comm := a2io.A2Gpio{}` with
+// `comm := a2io.UserIo{}` in the driver.go file to allow local testing
+package a2io
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type UserIo struct {
+}
+
+func (userIo UserIo) Init() {
+
+}
+
+func (userIo UserIo) WriteByte(data byte) error {
+	fmt.Printf("WriteByte: %02X\n", data)
+	return nil
+}
+
+func (userIo UserIo) WriteString(outString string) error {
+	fmt.Printf("WriteString: %s\n", strings.ReplaceAll(outString, "\r", "\n"))
+	return nil
+}
+
+func (userIo UserIo) WriteBlock(buffer []byte) error {
+	fmt.Printf("WriteBlock:\n")
+	return userIo.WriteBuffer(buffer)
+}
+
+func (userIo UserIo) WriteBuffer(buffer []byte) error {
+	fmt.Printf("WriteBuffer:\n")
+	for i, b := range buffer {
+		if i%16 == 0 {
+			fmt.Printf("\n%04X:", i)
+		}
+		fmt.Printf(" %02X", b)
+	}
+	fmt.Printf("\n")
+	return nil
+}
+
+func (userIo UserIo) ReadByte() (byte, error) {
+	fmt.Printf("ReadByte: ")
+	var b byte
+	fmt.Scanf("%x", &b)
+	fmt.Printf("\n")
+	return b, nil
+}
+
+func (userIo UserIo) ReadString() (string, error) {
+	fmt.Printf("ReadString: ")
+	var s string
+	fmt.Scanf("%s", &s)
+	fmt.Printf("\n")
+	return s, nil
+}
+
+func (userIo UserIo) ReadBlock(buffer []byte) error {
+	fmt.Printf("ReadBlock: (Not supported)")
+	return errors.New("ReadBlock not supported")
+}
diff --git a/RaspberryPi/apple2driver/driver.go b/RaspberryPi/apple2driver/driver.go
index beac08c..8f2f71c 100644
--- a/RaspberryPi/apple2driver/driver.go
+++ b/RaspberryPi/apple2driver/driver.go
@@ -1,3 +1,10 @@
+// Copyright Terence J. Boldt (c)2020-2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is contains the main driver code for the Raspberry Pi side of
+// the Apple2-IO-RPi hardware. Commands are sent from the Apple II and
+// responses are sent back from the Raspberry Pi.
 package main
 
 import (
diff --git a/RaspberryPi/apple2driver/handlers/block.go b/RaspberryPi/apple2driver/handlers/block.go
index 77d2c5d..c612464 100644
--- a/RaspberryPi/apple2driver/handlers/block.go
+++ b/RaspberryPi/apple2driver/handlers/block.go
@@ -1,3 +1,8 @@
+// Copyright Terence J. Boldt (c)2020-2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is used for handling ProDOS image block reading and writing
 package handlers
 
 import (
diff --git a/RaspberryPi/apple2driver/handlers/communication.go b/RaspberryPi/apple2driver/handlers/communication.go
index f19b248..e789326 100644
--- a/RaspberryPi/apple2driver/handlers/communication.go
+++ b/RaspberryPi/apple2driver/handlers/communication.go
@@ -1,3 +1,8 @@
+// Copyright Terence J. Boldt (c)2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is used for setting up the communications for the handlers
 package handlers
 
 import (
diff --git a/RaspberryPi/apple2driver/handlers/exec.go b/RaspberryPi/apple2driver/handlers/exec.go
index 9a8a997..9bff724 100644
--- a/RaspberryPi/apple2driver/handlers/exec.go
+++ b/RaspberryPi/apple2driver/handlers/exec.go
@@ -1,3 +1,9 @@
+// Copyright Terence J. Boldt (c)2020-2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is contains the handler for executing Linux and internal
+// commands
 package handlers
 
 import (
diff --git a/RaspberryPi/apple2driver/handlers/getTime.go b/RaspberryPi/apple2driver/handlers/getTime.go
index bd62193..5502c6a 100644
--- a/RaspberryPi/apple2driver/handlers/getTime.go
+++ b/RaspberryPi/apple2driver/handlers/getTime.go
@@ -1,3 +1,9 @@
+// Copyright Terence J. Boldt (c)2020-2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is contains the handler for retrieving the ProDOS timestamp
+// based on the current time
 package handlers
 
 import (
diff --git a/RaspberryPi/apple2driver/handlers/loadFile.go b/RaspberryPi/apple2driver/handlers/loadFile.go
index 8686d41..8de84e4 100644
--- a/RaspberryPi/apple2driver/handlers/loadFile.go
+++ b/RaspberryPi/apple2driver/handlers/loadFile.go
@@ -1,3 +1,9 @@
+// Copyright Terence J. Boldt (c)2020-2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is contains the handler for loading files directly from the
+// Raspberry Pi onto the Apple II
 package handlers
 
 import (
diff --git a/RaspberryPi/apple2driver/handlers/menu.go b/RaspberryPi/apple2driver/handlers/menu.go
index afe1262..8931225 100755
--- a/RaspberryPi/apple2driver/handlers/menu.go
+++ b/RaspberryPi/apple2driver/handlers/menu.go
@@ -1,3 +1,9 @@
+// Copyright Terence J. Boldt (c)2020-2021
+// Use of this source code is governed by an MIT
+// license that can be found in the LICENSE file.
+
+// This file is contains the handler for displaying the menu of choices on
+// the Apple II
 package handlers
 
 import (