From 0da3182c38f90ca6f2c7a1e5847036ccea4dd5e8 Mon Sep 17 00:00:00 2001
From: EkeEke <ekeeke31@gmail.com>
Date: Sun, 19 Aug 2012 01:13:03 +0200
Subject: [PATCH] [MD] fixed crash when loading TMSS ROM while MD BIOS is
 enabled / not found

---
 source/genesis.c | 6 ++++--
 source/membnk.c  | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/source/genesis.c b/source/genesis.c
index 21953a7..0b88097 100644
--- a/source/genesis.c
+++ b/source/genesis.c
@@ -378,7 +378,8 @@ void gen_tmss_w(unsigned int offset, unsigned int data)
 
 void gen_bankswitch_w(unsigned int data)
 {
-  if (system_hw == SYSTEM_MD)
+  /* check if BOOT ROM is loaded */
+  if (system_bios & SYSTEM_MD)
   {
     if (data & 1)
     {
@@ -395,7 +396,8 @@ void gen_bankswitch_w(unsigned int data)
 
 unsigned int gen_bankswitch_r(void)
 {
-  if (system_hw == SYSTEM_MD)
+  /* check if BOOT ROM is loaded */
+  if (system_bios & SYSTEM_MD)
   {
     return (m68k.memory_map[0].base == cart.base);
   }
diff --git a/source/membnk.c b/source/membnk.c
index 5b1369c..136ea42 100644
--- a/source/membnk.c
+++ b/source/membnk.c
@@ -193,7 +193,7 @@ void zbank_write_ctrl_io(unsigned int address, unsigned int data)
 
     case 0x41:  /* OS ROM */
     {
-      if (address & 1)
+      if ((config.bios & 1) && (address & 1))
       {
         gen_bankswitch_w(data & 1);
         return;