diff --git a/src/mame/video/megasys1.cpp b/src/mame/video/megasys1.cpp
index f140b29d717..6609f673920 100644
--- a/src/mame/video/megasys1.cpp
+++ b/src/mame/video/megasys1.cpp
@@ -447,7 +447,10 @@ WRITE16_MEMBER(megasys1_state::megasys1_vregs_A_w)
 							break;
 
 		case 0x308/2   :    soundlatch_word_w(space,0,new_data,0xffff);
-							m_audiocpu->set_input_line(4, HOLD_LINE);
+							if (!m_hardware_type_z)
+								m_audiocpu->set_input_line(4, HOLD_LINE);
+							else 
+								m_audiocpu->set_input_line(5, HOLD_LINE);
 							break;
 
 		default      :  SHOW_WRITE_ERROR("vreg %04X <- %04X",offset*2,data);