From 2258d011843cde39d030ad4ff81ccf0c378fd7e0 Mon Sep 17 00:00:00 2001
From: tomcw <tomcw@users.noreply.github.com>
Date: Sun, 28 Mar 2021 22:16:34 +0100
Subject: [PATCH] MB: SC01 is only mapped to the 6522 at Cn00

---
 source/CPU.cpp          | 2 +-
 source/Mockingboard.cpp | 3 ++-
 source/SSI263.cpp       | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/source/CPU.cpp b/source/CPU.cpp
index f069380a..357fb8de 100644
--- a/source/CPU.cpp
+++ b/source/CPU.cpp
@@ -105,7 +105,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 #include "YamlHelper.h"
 
-#define LOG_IRQ_TAKEN_AND_RTI 0
+#define LOG_IRQ_TAKEN_AND_RTI 1
 
 // 6502 Accumulator Bit Flags
 	#define	 AF_SIGN       0x80
diff --git a/source/Mockingboard.cpp b/source/Mockingboard.cpp
index bb3e9d93..346dc10a 100644
--- a/source/Mockingboard.cpp
+++ b/source/Mockingboard.cpp
@@ -608,7 +608,8 @@ static void SY6522_Write(BYTE nDevice, BYTE nReg, BYTE nValue)
 				nValue &= pMB->sy6522.DDRB;
 				pMB->sy6522.ORB = nValue;
 
-				if( (pMB->sy6522.DDRB == 0xFF) && (pMB->sy6522.PCR == 0xB0) )
+				if ((nDevice&1) == 0 && // SC01 only at $Cn00 (not $Cn80)
+					pMB->sy6522.DDRB == 0xFF && pMB->sy6522.PCR == 0xB0)
 				{
 					// Votrax speech data
 					pMB->ssi263.Votrax_Write(nValue);
diff --git a/source/SSI263.cpp b/source/SSI263.cpp
index ab059140..3312fe5e 100644
--- a/source/SSI263.cpp
+++ b/source/SSI263.cpp
@@ -40,7 +40,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 #define LOG_SSI263 0
 #define LOG_SSI263B 0	// Alternate SSI263 logging (use in conjunction with CPU.cpp's LOG_IRQ_TAKEN_AND_RTI)
-#define LOG_SC01 0
+#define LOG_SC01 1
 
 // SSI263A registers:
 #define SSI_DURPHON	0x00