From 6080fc101a95fb2a3271c1cdba5b2dd863c70d94 Mon Sep 17 00:00:00 2001
From: Phil Bennett
Date: Wed, 28 Jun 2017 19:30:21 -0700
Subject: - cbuster.cpp: Add a x3 hack to the YM2203 clock frequency to fix
incorrect pitch [Phil Bennett]
---
src/mame/drivers/cbuster.cpp | 3 ++-
src/mame/drivers/stfight.cpp | 5 +++--
2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/src/mame/drivers/cbuster.cpp b/src/mame/drivers/cbuster.cpp
index 74d16d4a231..75829b9d213 100644
--- a/src/mame/drivers/cbuster.cpp
+++ b/src/mame/drivers/cbuster.cpp
@@ -360,7 +360,8 @@ static MACHINE_CONFIG_START( twocrude )
MCFG_GENERIC_LATCH_8_ADD("soundlatch")
- MCFG_SOUND_ADD("ym1", YM2203, XTAL_32_22MHz/24) /* 1.3425MHz Verified */
+ // YM2203_PITCH_HACK - Pitch is too low at 1.3425MHz (see also stfight.cpp)
+ MCFG_SOUND_ADD("ym1", YM2203, XTAL_32_22MHz/24 * 3) /* 1.3425MHz Verified */
MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.60)
MCFG_YM2151_ADD("ym2", XTAL_32_22MHz/9) /* 3.58MHz Verified */
diff --git a/src/mame/drivers/stfight.cpp b/src/mame/drivers/stfight.cpp
index 9cb5ffbfda8..03dcf36c86a 100644
--- a/src/mame/drivers/stfight.cpp
+++ b/src/mame/drivers/stfight.cpp
@@ -248,7 +248,8 @@ TODO:
- stfight/empcity YM2203s should be clocked at 1.5MHz but this results in
the sound and music being 1/3 of the pitch they should be. The game never
writes the YM2203s' divider registers yet other games (e.g. Lock-On)
- suggest the default values are correct. What *is* going on here?
+ suggest the default values are correct.
+ cshootert however, sounds too high-pitched at 1.5MHz*3.
- Each version of empcity/stfight has a different protection code stored in the
MCU (at $1D2) so each 68705 will need to be dumped.
We currently use hacked versions of the empcityu MCU for each different set.
@@ -472,7 +473,7 @@ static MACHINE_CONFIG_START( stfight_base )
/* sound hardware */
MCFG_SPEAKER_STANDARD_MONO("mono")
- // HACK! These should be clocked at 1.5Mhz (see TODO list)
+ // YM2203_PITCH_HACK - These should be clocked at 1.5Mhz (see TODO list)
MCFG_SOUND_ADD("ym1", YM2203, XTAL_12MHz / 8 * 3)
MCFG_SOUND_ROUTE(0, "mono", 0.15)
MCFG_SOUND_ROUTE(1, "mono", 0.15)
--
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