From de47d1db5678780942af0a7891c76dce661783c9 Mon Sep 17 00:00:00 2001
From: ekeeke <ekeeke31@gmail.com>
Date: Fri, 23 Apr 2021 15:41:33 +0200
Subject: [PATCH] [Core/Sound] fixed MAME YM2413 core EG resolution bits
 (verified on YM2413B die, cf.
 https://www.smspower.org/Development/YM2413ReverseEngineeringNotes2015-03-20)

---
 HISTORY.txt                         |   3 +++
 builds/genesis_plus_gx_libretro.dll | Bin 2771030 -> 2771030 bytes
 builds/genplus_cube.dol             | Bin 3952960 -> 3952960 bytes
 builds/genplus_wii.dol              | Bin 4197888 -> 4197888 bytes
 core/sound/ym2413.c                 |   3 ++-
 5 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/HISTORY.txt b/HISTORY.txt
index 21573e3..e5b98bf 100644
--- a/HISTORY.txt
+++ b/HISTORY.txt
@@ -150,6 +150,9 @@ Genesis Plus GX 1.7.5 (xx/xx/xxxx) (Eke-Eke)
 * fixed YM2612 one-sample extra delay on operator1 output
 * fixed YM2612 LFO PM implementation: block & keyscale code should not be modified by LFO (verified on YM2612 die)
 * fixed YM2612 Timer B overflow handling
+* fixed YM2413 carrier/modulator phase reset after channel Key ON (Japanese Master System BIOS music)
+* fixed YM2413 intruments ROM (verified on YM2413B die)
+* fixed YM2413 EG resolution bits (verified on YM2413B die)
 
 [Gamecube/Wii]
 ---------------
diff --git a/builds/genesis_plus_gx_libretro.dll b/builds/genesis_plus_gx_libretro.dll
index 12566aab1ec433a67a85542ccf93813fcbe0be45..3c1a3e0cb7f39b78eebd026a8a530f762c1ee396 100644
GIT binary patch
delta 349
zcmW;IJxD@P6bJC@v;3%Tmin^H>{HD_cw<W-Nd$dJG`K5I=aw2Ge1sg#z_iJwJzScq
zw>0~vmIjB@&=x$}g93Z~ZTKDT;eXB<Zol1i^`U*Kq+f2X^2*8a1rxi76=FB>2=OSf
zhuBN(BlZ)I5swp3JhI&Lh72Kum9<bsFMEsUondbH<f}he`>qCB(k(>eKx>|g=5xx7
z1?83!ul-a5*BQrgteiGn@8uH0?hYKM@r9wzd06g8{+C+_8@rmlgRJ?GMAvx_%S?25
zpml@;_Sr9zCj^4ttZmKcBvrZTGU~c2VG;r`1=A3O5QIU68Hm6v%s~|9O<j$B=Dm8Q
qTr8K0^@1LQ1&Eskeer&PU#fdbORx+punKFCfFz_~-Sm{whaZ0vse_&X

delta 349
zcmXxg%Su8~6b9h!vAosJQcrd<yL!4naG(Mk1fm7eMWTTZAcvkHYU0Gf!i-ECok`=O
zNu%n#foI;p!D`Sfke;AGcfV1CZ?RcF>mTe^<H6H{#)X!(Z!Ys%X}8S89%7ByOWa4?
zPwXT169<Tc#3AAV;=yN@`~IjBLbw?hQ#3QTc-|`~9gwfVNcpRaWw;*l3Q;{YYfpxg
zh{&v#EPww7*DFdXH)r-5nz@u{-*uF#z1XFgJc$1vUm>jSneFXfc52w~F}XVNS5QAj
zLHoRm<V?_;yJITb(B+m#RV-b?5QJeEMj!%Fh=C5H5Qi}shY6T;EIsj=_pg~7C+W@g
mO2JCN6eOL3HT~GZFI9ZS8JLARn1=;OfdPxK<oJrqM;|{8_=8*k

diff --git a/builds/genplus_cube.dol b/builds/genplus_cube.dol
index dd26fb60e1a0f9af7ec81bd109f726663a4289f7..94a437c60eecbff2a719a36dc4a833be1e6081ff 100644
GIT binary patch
delta 262
zcmWN?Npb;U7=YpW1)+z;k2Zt|ZJyeckdP|JiWL@LRgPe(iVO5YRWD=N$B7$w7f(Ic
z(@kBm7bOvSkf_8YE{~Fsq!?m~CAK`tv!pKCbkr`e9DTOgclFv(+r$4r|B*k`Kh*K`
zQEh)iPa};CvT%??9t9Nff)dJjMFnrDq6QarG|)r~ZFJB@4}A<UgohEvm|%(--tmDs
P7Wl*$mRJR$_q}oN5I$s1

delta 262
zcmWN?%WeT-7=YpY&df~ttK-mWF{n|DLus87msLxPFL4Q7O1J?FiKSW2<!}Rd7f&94
zcU3;tq9i0?iAYpp5|@M|B_)QKV#$-FC3Dn<t?nn&)_aQ&j$WqJ?f=rzXF7ECAGx01
zs@o>;G@g;g3vA?&M*&5=;teId;{#<>P=$jU>S*8-O}J>`3vG1Jg@+#c7+{ERj4;Lz
PelfumGt5tcw^%t3UtDKS

diff --git a/builds/genplus_wii.dol b/builds/genplus_wii.dol
index 2b71ecf7899ef063a56a0b4afba6c437aa58c863..3540905db15d72ba7d876d5d059eb6f3caea8ccc 100644
GIT binary patch
delta 274
zcmWl~NlwCG7=Yolh#>QimdP^7q(EDS0y0Q1!aZOGU3`fbFmYqTf-8`8$pt(EXW?b>
z<njM}-M<q}bP36Wgym5p5|t;3Nn8?=l$4|;b5>hJI|MsJosw)elo!+XzZ*+k$h6g#
zer$Er_TR3fki|1zU?7J)3Mit4SC}ZHf+}jL;|&co(Lx&?yyF91^w5U|8x95-VuUeV
WOfba^pO|BTC06*tI&dBD|9S)0#7(gP

delta 274
zcmWl~$8Ex37=U5f5Q-B*{sa?>DZ!9Ju_+E6yh!$dqYt0N0!UntIIsc|M;2g)i~_tI
z9zDS}(1SbCM3<0+<v}76m6*iEkVkovggi@9UJhzuYS-h^RQm*5w(<?_viWPN6IqU0
z(ArTu?XvP*g;%^G1ruq!BZDk*$iqSbMU+s+2P&{pMGc?$!Z&_UM*~f?;J`&29dyxy
WhhOwDzz`#hF~Jlw%#WVypZ{-4@lde<

diff --git a/core/sound/ym2413.c b/core/sound/ym2413.c
index 98749f3..5e5463b 100644
--- a/core/sound/ym2413.c
+++ b/core/sound/ym2413.c
@@ -31,6 +31,7 @@ to do:
 /** 2011/xx/xx: removed multiple chips support, cleaned code & added FM board interface **/
 /** 2021/04/23: fixed synchronization of carrier/modulator phase reset after channel Key ON (fixes Japanese Master System BIOS music) **/
 /** 2021/04/24: fixed intruments ROM (verified on YM2413B die, cf. https://siliconpr0n.org/archive/doku.php?id=vendor:yamaha:opl2#ym2413_instrument_rom) **/
+/** 2021/04/24: fixed EG resolution bits (verified on YM2413B die, cf. https://www.smspower.org/Development/YM2413ReverseEngineeringNotes2015-03-20) **/
 
 #include "shared.h"
 
@@ -45,7 +46,7 @@ to do:
 #define ENV_LEN      (1<<ENV_BITS)
 #define ENV_STEP    (128.0/ENV_LEN)
 
-#define MAX_ATT_INDEX  ((1<<(ENV_BITS-2))-1) /*255*/
+#define MAX_ATT_INDEX  ((1<<(ENV_BITS-3))-1) /*127*/
 #define MIN_ATT_INDEX  (0)
 
 /* sinwave entries */