From 2f8e2f9a5e062f880bfe5f504cc473796572f408 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Wed, 14 Dec 2022 19:22:34 -0500
Subject: [PATCH] YM2612: partial, buggy CSM on ymfm

---
 src/engine/platform/genesis.cpp            | 2 +-
 src/engine/platform/sound/ymfm/ymfm_fm.ipp | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/engine/platform/genesis.cpp b/src/engine/platform/genesis.cpp
index 1f79cd0d4..9dd3699c7 100644
--- a/src/engine/platform/genesis.cpp
+++ b/src/engine/platform/genesis.cpp
@@ -209,12 +209,12 @@ void DivPlatformGenesis::acquire_ymfm(short* bufL, short* bufR, size_t start, si
       lastBusy=1;
     }
     
-    iface.clock();
     if (ladder) {
       fm_ymfm->generate(&out_ymfm);
     } else {
       ((ymfm::ym3438*)fm_ymfm)->generate(&out_ymfm);
     }
+    iface.clock();
     os[0]=out_ymfm.data[0];
     os[1]=out_ymfm.data[1];
     //OPN2_Write(&fm,0,0);
diff --git a/src/engine/platform/sound/ymfm/ymfm_fm.ipp b/src/engine/platform/sound/ymfm/ymfm_fm.ipp
index 6eab8308b..4fdff8a38 100644
--- a/src/engine/platform/sound/ymfm/ymfm_fm.ipp
+++ b/src/engine/platform/sound/ymfm/ymfm_fm.ipp
@@ -1521,7 +1521,7 @@ void fm_engine_base<RegisterType>::engine_timer_expired(uint32_t tnum)
 		for (uint32_t chnum = 0; chnum < CHANNELS; chnum++)
 			if (bitfield(RegisterType::CSM_TRIGGER_MASK, chnum))
 			{
-				m_channel[chnum]->keyonoff(1, KEYON_CSM, chnum);
+				m_channel[chnum]->keyonoff(0xf, KEYON_CSM, chnum);
 				m_modified_channels |= 1 << chnum;
 			}