diff --git a/cores/esp8266/FileSystem.cpp b/cores/esp8266/FileSystem.cpp
index 7e42af06b..f2517cf98 100755
--- a/cores/esp8266/FileSystem.cpp
+++ b/cores/esp8266/FileSystem.cpp
@@ -21,41 +21,46 @@
 #include "FileSystem.h"
 #include "Arduino.h"
 
-boolean FSClass::mount(){
-  if(_mounted) return true;
+bool FSClass::mount() {
+  if (_mounted) 
+    return true;
+
   _mounted = spiffs_mount();
   return _mounted;
 }
 
-void FSClass::unmount(){
-  if(!_mounted) return;
+void FSClass::unmount() {
+  if (!_mounted)
+    return;
+
   spiffs_unmount();
   _mounted = false;
 }
 
-boolean FSClass::format(){
+bool FSClass::format() {
   return spiffs_format();
 }
 
-boolean FSClass::exists(const char *filename){
+bool FSClass::exists(const char *filename) {
   spiffs_stat stat = {0};
-  if (SPIFFS_stat(&_filesystemStorageHandle, filename, &stat) < 0) return false;
+  if (SPIFFS_stat(&_filesystemStorageHandle, filename, &stat) < 0) 
+    return false;
   return stat.name[0] != '\0';
 }
 
-boolean FSClass::create(const char *filepath){
+bool FSClass::create(const char *filepath){
   return SPIFFS_creat(&_filesystemStorageHandle, filepath, 0) == 0;
 }
 
-boolean FSClass::remove(const char *filepath){
+bool FSClass::remove(const char *filepath){
   return SPIFFS_remove(&_filesystemStorageHandle, filepath) == 0;
 }
 
-boolean FSClass::rename(const char *filename, const char *newname){
+bool FSClass::rename(const char *filename, const char *newname) {
   return SPIFFS_rename(&_filesystemStorageHandle, filename, newname) == 0;
 }
 
-FSFile FSClass::open(const char *filename, uint8_t mode){
+FSFile FSClass::open(const char *filename, uint8_t mode) {
   int repeats = 0;
   bool notExist;
   bool canRecreate = (mode & SPIFFS_CREAT) == SPIFFS_CREAT;
@@ -81,25 +86,25 @@ FSFile FSClass::open(const char *filename, uint8_t mode){
 
 FSClass FS;
 
-FSFile::FSFile(){
+FSFile::FSFile() {
   _file = 0;
   _stats = {0};
 }
 
-FSFile::FSFile(file_t f){
+FSFile::FSFile(file_t f) {
   _file = f;
   if(SPIFFS_fstat(&_filesystemStorageHandle, _file, &_stats) != 0){
     debugf("mount errno %d\n", SPIFFS_errno(&_filesystemStorageHandle));
   }
 }
 
-void FSFile::close(){
+void FSFile::close() {
   if (! _file) return;
   SPIFFS_close(&_filesystemStorageHandle, _file);
   _file = 0;
 }
 
-uint32_t FSFile::size(){
+uint32_t FSFile::size() {
   if(! _file) return 0;
   uint32_t pos = SPIFFS_tell(&_filesystemStorageHandle, _file);
   SPIFFS_lseek(&_filesystemStorageHandle, _file, 0, SPIFFS_SEEK_END);
@@ -108,31 +113,31 @@ uint32_t FSFile::size(){
   return size;
 }
 
-uint32_t FSFile::seek(uint32_t pos){
+uint32_t FSFile::seek(uint32_t pos) {
   if (! _file) return 0;
   return SPIFFS_lseek(&_filesystemStorageHandle, _file, pos, SPIFFS_SEEK_SET);
 }
 
-uint32_t FSFile::position(){
+uint32_t FSFile::position() {
   if (! _file) return 0;
   return SPIFFS_tell(&_filesystemStorageHandle, _file);
 }
 
-boolean FSFile::eof(){
+bool FSFile::eof() {
   if (! _file) return 0;
   return SPIFFS_eof(&_filesystemStorageHandle, _file);
 }
 
-boolean FSFile::isDirectory(void){
+bool FSFile::isDirectory(void) {
   return false;
 }
 
-int FSFile::read(void *buf, uint16_t nbyte){
+int FSFile::read(void *buf, uint16_t nbyte) {
   if (! _file) return -1;
   return SPIFFS_read(&_filesystemStorageHandle, _file, buf, nbyte);
 }
 
-int FSFile::read(){
+int FSFile::read() {
   if (! _file) return -1;
   int val;
   if(SPIFFS_read(&_filesystemStorageHandle, _file, &val, 1) != 1) return -1;
diff --git a/cores/esp8266/FileSystem.h b/cores/esp8266/FileSystem.h
index 8704f260c..d675da114 100755
--- a/cores/esp8266/FileSystem.h
+++ b/cores/esp8266/FileSystem.h
@@ -29,7 +29,7 @@ class String;
 #define FSFILE_WRITE (SPIFFS_RDONLY | SPIFFS_WRONLY | SPIFFS_CREAT | SPIFFS_APPEND | SPIFFS_TRUNC)
 
 class FSFile : public Stream {
- private:
+private:
   spiffs_stat _stats; 
   file_t _file;
 
@@ -47,34 +47,29 @@ public:
   uint32_t remove();
   uint32_t position();
   uint32_t size();
-  boolean eof();
+  bool eof();
   void close();
   int lastError();
   void clearError();
-  operator bool(){ return _file > 0; }
+  operator bool() { return _file > 0; }
   char * name();
-  boolean isDirectory(void);
+  bool isDirectory(void);
 
   template<typename T> size_t write(T &src){
-    uint8_t obuf[64];
-    size_t doneLen = 0;
-    size_t sentLen;
-    int i;
-
-    while (src.available() > 64){
-      src.read(obuf, 64);
-      sentLen = write(obuf, 64);
-      doneLen = doneLen + sentLen;
-      if(sentLen != 64){
-        return doneLen;
+    const size_t bufferSize = 64;
+    uint8_t obuf[bufferSize];
+    size_t bytesWritten = 0;
+    while (true){
+      size_t available = src.available();
+      size_t willWrite = (available < bufferSize) ? available : bufferSize;
+      src.read(obuf, willWrite);
+      size_t cb = write(obuf, willWrite);
+      bytesWritten += cb;
+      if (cb != willWrite) {
+        return bytesWritten;
       }
     }
-  
-    size_t leftLen = src.available();
-    src.read(obuf, leftLen);
-    sentLen = write(obuf, leftLen);
-    doneLen = doneLen + sentLen;
-    return doneLen;
+    return bytesWritten;
   }
   
   using Print::write;
@@ -83,16 +78,16 @@ public:
 class FSClass {
 
 private:
-  boolean _mounted;
+  bool _mounted;
   
 public:
-  boolean mount();
+  bool mount();
   void unmount();
-  boolean format();
-  boolean exists(const char *filename);
-  boolean create(const char *filepath);
-  boolean remove(const char *filepath);
-  boolean rename(const char *filename, const char *newname);
+  bool format();
+  bool exists(const char *filename);
+  bool create(const char *filepath);
+  bool remove(const char *filepath);
+  bool rename(const char *filename, const char *newname);
   
   FSFile open(const char *filename, uint8_t mode = FSFILE_READ);
 
diff --git a/cores/esp8266/spiffs/spiffs.h b/cores/esp8266/spiffs/spiffs.h
index ad922b4a8..6357b44a7 100755
--- a/cores/esp8266/spiffs/spiffs.h
+++ b/cores/esp8266/spiffs/spiffs.h
@@ -12,8 +12,6 @@
 extern "C" {
 #endif
 
-//#include "c_stdio.h"
-#include <user_config.h>
 #include "spiffs_config.h"
 #include "flashmem.h"