From 83d4312e3cb2c2625359f4c8ae1a68c876caaf6c Mon Sep 17 00:00:00 2001
From: ekeeke31 <ekeeke31@fcb46045-4337-0410-a722-cd382f7ce8f6>
Date: Sun, 5 Feb 2012 17:00:50 +0000
Subject: [PATCH] added random RAM pattern initialization on Mark-III &
 Japanese Master System (fixes "Alibaba and 40 Thieves" & "Block Hole")

---
 source/cart_hw/sms_cart.c | 21 +++++++++++----------
 source/genesis.c          |  9 ++++++++-
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/source/cart_hw/sms_cart.c b/source/cart_hw/sms_cart.c
index e6327d1..799127d 100644
--- a/source/cart_hw/sms_cart.c
+++ b/source/cart_hw/sms_cart.c
@@ -38,9 +38,6 @@
 
 #include "shared.h"
 #include "terebi_oekaki.h"
-#ifdef NGC
-#include "cheats.h"
-#endif
 
 #define MAPPER_NONE   (0)
 #define MAPPER_TEREBI (1)
@@ -52,7 +49,7 @@
 #define MAPPER_93C46  (7)
 #define MAPPER_MULTI  (8)
 
-#define GAME_DATABASE_CNT (188)
+#define GAME_DATABASE_CNT (190)
 
 typedef struct
 {
@@ -133,6 +130,10 @@ static const rominfo_t game_list[GAME_DATABASE_CNT] =
   {0xBD1CC7DF, 0, 0, SYSTEM_MS_GAMEPAD,  MAPPER_SEGA,   SYSTEM_MARKIII, REGION_JAPAN_NTSC}, /* Super Tetris (K) */
   {0x6D309AC5, 0, 0, SYSTEM_MS_GAMEPAD,  MAPPER_SEGA,   SYSTEM_MARKIII, REGION_JAPAN_NTSC}, /* Power Boggle Boggle (K) */
 
+  /* games requiring random RAM pattern initialization */
+  {0x08BF3DE3, 0, 0, SYSTEM_MS_GAMEPAD,  MAPPER_NONE,   SYSTEM_MARKIII, REGION_JAPAN_NTSC}, /* Alibaba and 40 Thieves (KR) */
+  {0x643B6B76, 0, 0, SYSTEM_MS_GAMEPAD,  MAPPER_NONE,   SYSTEM_MARKIII, REGION_JAPAN_NTSC}, /* Block Hole (KR) */
+
   /* games requiring PAL timings */
   {0x72420F38, 0, 0, SYSTEM_MS_GAMEPAD,  MAPPER_SEGA,   SYSTEM_SMS2,     REGION_EUROPE}, /* Addams Familly */
   {0x2D48C1D3, 0, 0, SYSTEM_MS_GAMEPAD,  MAPPER_SEGA,   SYSTEM_SMS2,     REGION_EUROPE}, /* Back to the Future Part III */
@@ -932,9 +933,9 @@ static void mapper_8k_w(int offset, unsigned int data)
     }
   }
 
-#ifdef NGC
-  /* update ROM patches */
-  ROMCheatUpdate();
+#ifdef CHEATS_UPDATE
+  /* update ROM patches when banking has changed */
+  CHEATS_UPDATE();
 #endif
 }
     
@@ -1076,9 +1077,9 @@ static void mapper_16k_w(int offset, unsigned int data)
     }
   }
 
-#ifdef NGC
-  /* update ROM patches */
-  ROMCheatUpdate();
+#ifdef CHEATS_UPDATE
+  /* update ROM patches when banking has changed */
+  CHEATS_UPDATE();
 #endif
 }
 
diff --git a/source/genesis.c b/source/genesis.c
index 536a9ab..7b3e7f1 100644
--- a/source/genesis.c
+++ b/source/genesis.c
@@ -218,7 +218,7 @@ void gen_reset(int hard_reset)
   /* System Reset */
   if (hard_reset)
   {
-    /* clear RAM (TODO: use random bit patterns as on real hardware) */
+    /* clear RAM (TODO: use random bit patterns for all systems, like on real hardware) */
     memset(work_ram, 0x00, sizeof (work_ram));
     memset(zram, 0x00, sizeof (zram));
   }
@@ -286,6 +286,13 @@ void gen_reset(int hard_reset)
   }
   else
   {
+    /* RAM state at power-on is undefined on some systems */
+    if ((system_hw == SYSTEM_MARKIII) || ((system_hw & SYSTEM_SMS) && (region_code == REGION_JAPAN_NTSC)))
+    {
+      /* some korean games rely on RAM to be initialized with values different from $00 or $ff */
+      memset(work_ram, 0xf0, sizeof(work_ram));
+    }
+
     /* Z80 cycles should be a multiple of 15 to avoid rounding errors */
     mcycles_z80 = (mcycles_z80 / 15) * 15;