diff --git a/src/mame/drivers/cgang.cpp b/src/mame/drivers/cgang.cpp
index 2a5ac175cd7..811c0346a04 100644
--- a/src/mame/drivers/cgang.cpp
+++ b/src/mame/drivers/cgang.cpp
@@ -774,7 +774,6 @@ void cgang_state::cgang(machine_config &config)
 	m_ppi[1]->in_pb_callback().set(FUNC(cgang_state::ppi2_b_r));
 	m_ppi[1]->in_pc_callback().set_ioport("SW4").lshift(4);
 	m_ppi[1]->out_pc_callback().set(FUNC(cgang_state::ppi2_c_w));
-	m_ppi[1]->tri_pc_callback().set_constant(0);
 
 	I8255(config, m_ppi[2]); // 0x80: all = output
 	m_ppi[2]->out_pa_callback().set(FUNC(cgang_state::ppi3_a_w));
@@ -791,6 +790,13 @@ void cgang_state::cgang(machine_config &config)
 	m_ppi[4]->out_pb_callback().set(FUNC(cgang_state::ppi5_b_w));
 	m_ppi[4]->in_pc_callback().set(FUNC(cgang_state::ppi5_c_r));
 
+	for (int i = 0; i < 5; i++)
+	{
+		m_ppi[i]->tri_pa_callback().set_constant(0);
+		m_ppi[i]->tri_pb_callback().set_constant(0);
+		m_ppi[i]->tri_pc_callback().set_constant(0);
+	}
+
 	WATCHDOG_TIMER(config, m_watchdog); // HA1835P
 	m_watchdog->set_time(attotime::from_msec(100)); // approximation