diff --git a/consensus/ethash/ethash.go b/consensus/ethash/ethash.go
index ac049f9c36..701f6c51ea 100644
--- a/consensus/ethash/ethash.go
+++ b/consensus/ethash/ethash.go
@@ -64,6 +64,8 @@ func isLittleEndian() bool {
 }
 
 // memoryMap tries to memory map a file of uint32s for read only access.
+// mmap is a portable memory map package which would enable direct access for 
+// memory mapping files
 func memoryMap(path string) (*os.File, mmap.MMap, []uint32, error) {
 	file, err := os.OpenFile(path, os.O_RDONLY, 0644)
 	if err != nil {
@@ -346,7 +348,8 @@ func (d *dataset) generate(dir string, limit int, test bool) {
 	})
 }
 
-// finalizer closes any file handlers and memory maps open.
+// finalizer closes any file handlers and use Unmap() to deletes the memory mapped region,
+// flushes any remaining changes.
 func (d *dataset) finalizer() {
 	if d.mmap != nil {
 		d.mmap.Unmap()
diff --git a/console/console.go b/console/console.go
index 1bceb7bc65..81711e7726 100644
--- a/console/console.go
+++ b/console/console.go
@@ -60,11 +60,11 @@ type Config struct {
 	Preload  []string     // Absolute paths to JavaScript files to preload
 }
 
-// Console is a JavaScript interpreted runtime environment. It is a fully fleged
+// Console is a JavaScript interpreted runtime environment. It is a fully fledged
 // JavaScript console attached to a running node via an external or in-process RPC
 // client.
 type Console struct {
-	client   *rpc.Client  // RPC client to execute Ethereum requests through
+	client   *rpc.Client  // RPC client to execute Ethereum requests through rpc
 	jsre     *jsre.JSRE   // JavaScript runtime environment running the interpreter
 	prompt   string       // Input prompt prefix string
 	prompter UserPrompter // Input prompter to allow interactive user feedback
@@ -76,7 +76,7 @@ type Console struct {
 // New initializes a JavaScript interpreted runtime environment and sets defaults
 // with the config struct.
 func New(config Config) (*Console, error) {
-	// Handle unset config values gracefully
+	// Handle unset config values with default value
 	if config.Prompter == nil {
 		config.Prompter = Stdin
 	}
@@ -84,7 +84,7 @@ func New(config Config) (*Console, error) {
 		config.Prompt = DefaultPrompt
 	}
 	if config.Printer == nil {
-		config.Printer = colorable.NewColorableStdout()
+		config.Printer = colorable.NewColorableStdout() // colorful standard output
 	}
 	// Initialize the console and return
 	console := &Console{