From fd7d4a31601bd9fa7ac8b1d24c947ded7e98d74c Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Sat, 28 Feb 2026 13:07:03 +1000
Subject: [PATCH] CDROM: Set motor on bit immediately on MotorOn

Fixes disc change in Armored Core - Master of Arena.
---
 src/core/cdrom.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/core/cdrom.cpp b/src/core/cdrom.cpp
index d83347e9e..c36b9341a 100644
--- a/src/core/cdrom.cpp
+++ b/src/core/cdrom.cpp
@@ -2279,8 +2279,9 @@ void CDROM::ExecuteCommand(void*, TickCount ticks, TickCount ticks_late)
           return;
         }
 
-        if (CanReadMedia())
-          StartMotor();
+        // ensure bit is set, Armored Core - Master of Arena relies on it
+        s_state.secondary_status.motor_on = true;
+        StartMotor();
 
         QueueCommandSecondResponse(Command::MotorOn, MOTOR_ON_RESPONSE_TICKS);
       }