From 2a0ca1b236004dcf4914c377a5eaba12630902da Mon Sep 17 00:00:00 2001
From: sanni <sanni@users.noreply.github.com>
Date: Fri, 15 Sep 2017 17:51:41 +0200
Subject: [PATCH] V28D: Simplify GBA Logo Check

---
 Cart_Reader/Cart_Reader.ino |  6 +++---
 Cart_Reader/GBA.ino         | 35 ++++++-----------------------------
 2 files changed, 9 insertions(+), 32 deletions(-)

diff --git a/Cart_Reader/Cart_Reader.ino b/Cart_Reader/Cart_Reader.ino
index 7f1bc29..dc45c18 100644
--- a/Cart_Reader/Cart_Reader.ino
+++ b/Cart_Reader/Cart_Reader.ino
@@ -2,8 +2,8 @@
                     Cartridge Reader for Arduino Mega2560
 
    Author:           sanni
-   Date:             2017-09-14
-   Version:          V28C
+   Date:             2017-09-15
+   Version:          V28D
 
    SD  lib:         https://github.com/greiman/SdFat
    LCD lib:         https://github.com/adafruit/Adafruit_SSD1306
@@ -34,7 +34,7 @@
    YamaArashi - GBA flashrom bank switch command
 
 **********************************************************************************/
-char ver[5] = "V28C";
+char ver[5] = "V28D";
 
 /******************************************
    Define Output
diff --git a/Cart_Reader/GBA.ino b/Cart_Reader/GBA.ino
index 6438a3a..145e300 100644
--- a/Cart_Reader/GBA.ino
+++ b/Cart_Reader/GBA.ino
@@ -8,19 +8,6 @@
 char calcChecksumStr[5];
 boolean readType;
 
-static const int nintendoLogo[] PROGMEM = {
-  0x00, 0x00, 0x00, 0x00, 0x24, 0xFF, 0xAE, 0x51, 0x69, 0x9A, 0xA2, 0x21, 0x3D, 0x84, 0x82, 0x0A,
-  0x84, 0xE4, 0x09, 0xAD, 0x11, 0x24, 0x8B, 0x98, 0xC0, 0x81, 0x7F, 0x21, 0xA3, 0x52, 0xBE, 0x19,
-  0x93, 0x09, 0xCE, 0x20, 0x10, 0x46, 0x4A, 0x4A, 0xF8, 0x27, 0x31, 0xEC, 0x58, 0xC7, 0xE8, 0x33,
-  0x82, 0xE3, 0xCE, 0xBF, 0x85, 0xF4, 0xDF, 0x94, 0xCE, 0x4B, 0x09, 0xC1, 0x94, 0x56, 0x8A, 0xC0,
-  0x13, 0x72, 0xA7, 0xFC, 0x9F, 0x84, 0x4D, 0x73, 0xA3, 0xCA, 0x9A, 0x61, 0x58, 0x97, 0xA3, 0x27,
-  0xFC, 0x03, 0x98, 0x76, 0x23, 0x1D, 0xC7, 0x61, 0x03, 0x04, 0xAE, 0x56, 0xBF, 0x38, 0x84, 0x00,
-  0x40, 0xA7, 0x0E, 0xFD, 0xFF, 0x52, 0xFE, 0x03, 0x6F, 0x95, 0x30, 0xF1, 0x97, 0xFB, 0xC0, 0x85,
-  0x60, 0xD6, 0x80, 0x25, 0xA9, 0x63, 0xBE, 0x03, 0x01, 0x4E, 0x38, 0xE2, 0xF9, 0xA2, 0x34, 0xFF,
-  0xBB, 0x3E, 0x03, 0x44, 0x78, 0x00, 0x90, 0xCB, 0x88, 0x11, 0x3A, 0x94, 0x65, 0xC0, 0x7C, 0x63,
-  0x87, 0xF0, 0x3C, 0xAF, 0xD6, 0x25, 0xE4, 0x8B, 0x38, 0x0A, 0xAC, 0x72, 0x21, 0xD4, 0xF8, 0x07
-};
-
 /******************************************
    Menu
  *****************************************/
@@ -750,8 +737,8 @@ void writeByte_GBA(unsigned long myAddress, byte myData) {
 /******************************************
   GBA ROM Functions
 *****************************************/
-// Test known Nintendo header for errors and sets read method to either sequential or random access
-int testHeader() {
+// Read info out of rom header
+void getCartInfo_GBA() {
   // Read Header into array
   for (int currWord = 0; currWord < 192; currWord += 2) {
     word tempWord = readWord_GBA(currWord);
@@ -760,24 +747,14 @@ int testHeader() {
     sdBuffer[currWord + 1] = (tempWord >> 8) & 0xFF;
   }
 
-  // Compare Nintendo logo, 156 bytes starting at 0x04
-  int errors = 0;
+  // Compare Nintendo logo against known checksum, 156 bytes starting at 0x04
+  byte logoChecksum = 0;
   for (int currByte = 0x4; currByte < 0xA0; currByte++) {
-    if (pgm_read_byte(&nintendoLogo[currByte]) != sdBuffer[currByte]) {
-      errors++;
-    }
+    logoChecksum += sdBuffer[currByte];
   }
-  return errors;
-}
 
-// Read info out of rom header
-void getCartInfo_GBA() {
-  // Test rom header for errors
-  int logoErrors =  testHeader();
-
-  if (logoErrors != 0) {
+  if (logoChecksum != 0x1B) {
     print_Error(F("CARTRIDGE ERROR"), false);
-    cartSize = 32;
     strcpy(romName, "ERROR");
     println_Msg(F(""));
     println_Msg(F(""));