From 38bb5b1f51ca34fc6ceb452a393d450830a69514 Mon Sep 17 00:00:00 2001
From: "Alex W. Jackson" <alex.w.jackson@gmail.com>
Date: Tue, 7 May 2024 17:32:15 -0400
Subject: [PATCH] Make X24C02 only enter read/write state if I2C address
 matches; fixes SD Gundam Gaiden 2

---
 src/boards/bandai.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/boards/bandai.cpp b/src/boards/bandai.cpp
index e908a3ae..9f0bbe1a 100644
--- a/src/boards/bandai.cpp
+++ b/src/boards/bandai.cpp
@@ -178,9 +178,12 @@ static void x24c02_write(uint8 data) {
 				x24c02_addr <<= 1;
 				x24c02_addr |= sda;
 			} else {
-				if (sda)					// READ COMMAND
+				if ((x24c02_addr & 0x78) != 0x50) {	// WRONG DEVICE ADDRESS
+					x24c02_out = 1;
+					x24c02_state = X24C0X_STANDBY;
+				} else if (sda)					// READ COMMAND
 					x24c02_state = X24C0X_READ;
-				else						// WRITE COMMAND
+				else							// WRITE COMMAND
 					x24c02_state = X24C0X_WORD;
 			}
 			x24c02_bitcount++;