diff --git a/src/emu/cpu/tms57002/tms57002.c b/src/emu/cpu/tms57002/tms57002.c
index 2433930cb6d..0ca9abbeba6 100644
--- a/src/emu/cpu/tms57002/tms57002.c
+++ b/src/emu/cpu/tms57002/tms57002.c
@@ -97,7 +97,7 @@ typedef struct {
 
 	UINT32 xm_adr;
 
-	UINT8 host[4], hidx;
+	UINT8 host[4], hidx, allow_update;
 
 	cd cache;
 
@@ -275,6 +275,7 @@ WRITE8_DEVICE_HANDLER(tms57002_data_w)
 				UINT32 val = (s->host[0]<<24) | (s->host[1]<<16) | (s->host[2]<<8) | s->host[3];
 				s->cmem[s->sa] = val;
 				s->sti &= ~SU_CVAL;
+				s->allow_update = 0;
 			}
 		} else {
 			s->sa = data;
@@ -329,6 +330,7 @@ void tms57002_sync(const device_config *device)
 	if(s->sti & (IN_PLOAD | IN_CLOAD))
 		return;
 
+	s->allow_update = 1;
 	s->pc = 0;
 	s->ca = 0;
 	s->id = 0;
diff --git a/src/emu/cpu/tms57002/tmsinstr.lst b/src/emu/cpu/tms57002/tmsinstr.lst
index d50732d5cdd..6c1583f1e4e 100644
--- a/src/emu/cpu/tms57002/tmsinstr.lst
+++ b/src/emu/cpu/tms57002/tmsinstr.lst
@@ -441,6 +441,7 @@ sfma 2b 5b 1 n f
 
 sfml 1  34 1 y
   sfml
+  s->macc = (s->macc & 0x8000000000000ULL) | ((s->macc << 1) & 0x7ffffffffffffULL);
 
 sfmo 2a 60 1 n f
   sfmo 0
@@ -471,6 +472,7 @@ slml 2a 07 1 y
 
 smhc 2a 05 1 y
   smhc %c
+  %wc(%mo >> 16);
 
 smhd 2a 03 1 y
   smhd %d