From 29e81096062c9847b95472f97bdccc7cf5c909cb Mon Sep 17 00:00:00 2001
From: Robert Neumann <mail.ramadev@gmail.com>
Date: Wed, 11 Sep 2019 20:02:26 +0200
Subject: [PATCH] SNES, MD: avoid dumping/writing 0 Byte files to SD card

---
 Cart_Reader/MD.ino   | 16 ++++++++++++----
 Cart_Reader/N64.ino  |  1 +
 Cart_Reader/SNES.ino | 43 +++++++++++++++++++++++++------------------
 3 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/Cart_Reader/MD.ino b/Cart_Reader/MD.ino
index b10841e..9d87de8 100644
--- a/Cart_Reader/MD.ino
+++ b/Cart_Reader/MD.ino
@@ -195,10 +195,18 @@ void mdCartMenu() {
   {
     case 0:
       display_Clear();
-      // Change working dir to root
-      sd.chdir("/");
-      readROM_MD();
-      //compare_checksum_MD();
+
+      // common ROM read fail state: no cart inserted - tends to report impossibly large cartSize
+      // largest known game so far is supposedly "Paprium" at 10MB, so cap sanity check at 16MB
+      if (cartSize != 0 && cartSize <= 16777216) {
+        // Change working dir to root
+        sd.chdir("/");
+        readROM_MD();
+        //compare_checksum_MD();
+      }
+      else {
+        print_Error(F("Cart has no ROM"), false);
+      }
       break;
 
     case 1:
diff --git a/Cart_Reader/N64.ino b/Cart_Reader/N64.ino
index ffaaa84..c8b4cd2 100644
--- a/Cart_Reader/N64.ino
+++ b/Cart_Reader/N64.ino
@@ -298,6 +298,7 @@ void n64CartMenu() {
         }
       }
       else {
+        display_Clear();
         print_Error(F("Savetype Error"), false);
       }
       println_Msg(F("Press Button..."));
diff --git a/Cart_Reader/SNES.ino b/Cart_Reader/SNES.ino
index abce40a..e7e6f20 100644
--- a/Cart_Reader/SNES.ino
+++ b/Cart_Reader/SNES.ino
@@ -49,7 +49,7 @@ static const char confMenuItem2[] PROGMEM = "4MB LoRom 256K Sram";
 static const char confMenuItem3[] PROGMEM = "4MB HiRom 64K Sram";
 static const char confMenuItem4[] PROGMEM = "6MB ExRom 256K Sram";
 static const char confMenuItem5[] PROGMEM = "Reset";
-static const char* const menuOptionsConf[] PROGMEM = {confMenuItem1, confMenuItem2, confMenuItem3, confMenuItem4, confMenuItem5};
+static const char* const menuOptionsConfManual[] PROGMEM = {confMenuItem1, confMenuItem2, confMenuItem3, confMenuItem4, confMenuItem5};
 
 // SNES start menu
 void snsMenu() {
@@ -118,19 +118,25 @@ void snesMenu() {
   {
     case 0:
       {
-        display_Clear();
-        // Change working dir to root
-        sd.chdir("/");
-        // get current time
-        unsigned long startTime = millis();
-        // start reading from cart
-        readROM_SNES();
-        compare_checksum();
-        // print elapsed time
-        print_Msg(F("Time elapsed: "));
-        print_Msg((millis() - startTime) / 1000);
-        println_Msg(F("s"));
-        display_Update();
+        if (numBanks > 0) {
+          display_Clear();
+          // Change working dir to root
+          sd.chdir("/");
+          // get current time
+          unsigned long startTime = millis();
+          // start reading from cart
+          readROM_SNES();
+          compare_checksum();
+          // print elapsed time
+          print_Msg(F("Time elapsed: "));
+          print_Msg((millis() - startTime) / 1000);
+          println_Msg(F("s"));
+          display_Update();
+        }
+        else {
+          display_Clear();
+          print_Error(F("Does not have ROM"), false);
+        }
       }
       break;
 
@@ -239,11 +245,11 @@ void snesMenu() {
 }
 
 // Menu for manual configuration
-void confMenu() {
+void confMenuManual() {
   // create menu with title and 5 options to choose from
   unsigned char subMenu;
   // Copy menuOptions out of progmem
-  convertPgm(menuOptionsConf, 5);
+  convertPgm(menuOptionsConfManual, 5);
   subMenu = question_box(F("Choose mapping"), menuOptions, 5, 0);
 
   // wait for user choice to come back from the question box menu
@@ -658,7 +664,7 @@ void getCartInfo_SNES() {
 
   // Start manual config
   if (manualConfig == 1) {
-    confMenu();
+    confMenuManual();
   }
 }
 
@@ -834,7 +840,8 @@ boolean checkcart_SNES() {
   }
 
   // Calculate sramSize
-  if (sramSizeExp != 0) {
+  // Fail states usually have sramSizeExp at 255 (no cart inserted, SA-1 failure, etc)
+  if (sramSizeExp != 0 && sramSizeExp != 255) {
     sramSizeExp = sramSizeExp + 3;
     sramSize = 1;
     while (sramSizeExp--)