From c01425d99a3f48f5dd25a2d78aa2b82d01f27a71 Mon Sep 17 00:00:00 2001
From: Sergey Dvodnenko <dvodnenkos@yandex.ua>
Date: Sun, 25 Oct 2020 17:59:56 +0200
Subject: [PATCH] snes: add special LoRom mapping (Derby Stallion 96 and Sound
 Novel Tsukuru)

---
 support/snes/snes.cpp | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/support/snes/snes.cpp b/support/snes/snes.cpp
index ed5722d..a606183 100644
--- a/support/snes/snes.cpp
+++ b/support/snes/snes.cpp
@@ -166,8 +166,18 @@ uint8_t* snes_get_header(fileTYPE *f)
 					}
 				}
 
-				//Rom type: 0-Low, 1-High, 2-ExHigh
-				hdr[1] = (addr == 0x00ffc0) ? 1 : (addr == 0x40ffc0) ? 2 : 0;
+				bool has_bsx_slot = true;
+				if (buf[addr - 14] == 'Z' && buf[addr - 11] == 'J' && 
+					((buf[addr - 13] >= 'A' && buf[addr - 13] <= 'Z') || (buf[addr - 13] >= '0' && buf[addr - 13] <= '9')) &&
+					(buf[addr + Company] == 0x33 || (buf[addr - 10] == 0x00 && buf[addr - 4] == 0x00)) ) {
+					has_bsx_slot = true;
+				}
+
+				//Rom type: 0-Low, 1-High, 2-ExHigh, 3-SpecialLoRom
+				hdr[1] = (addr == 0x00ffc0) ? 1 : 
+						 (addr == 0x40ffc0) ? 2 : 
+						 has_bsx_slot ? 3 : 
+						 0;
 
 				//BSX 3
 				if (is_bsx_bios) {