diff --git a/src/devices/machine/6850acia.cpp b/src/devices/machine/6850acia.cpp
index 0a89b94d337..d428851ad8f 100644
--- a/src/devices/machine/6850acia.cpp
+++ b/src/devices/machine/6850acia.cpp
@@ -2,7 +2,7 @@
 // copyright-holders:smf
 /*********************************************************************
 
-    6850acia.c
+    6850acia.cpp
 
     6850 ACIA code
 
@@ -92,6 +92,7 @@ acia6850_device::acia6850_device(const machine_config &mconfig, device_type type
 	, m_irq(0)
 	, m_txc(0)
 	, m_txd(0)
+	, m_tx_state(0)
 	, m_tx_counter(0)
 	, m_tx_irq_enable(false)
 	, m_rxc(0)
diff --git a/src/devices/machine/upd4992.cpp b/src/devices/machine/upd4992.cpp
index 5d28bb3037c..60a2eece92b 100644
--- a/src/devices/machine/upd4992.cpp
+++ b/src/devices/machine/upd4992.cpp
@@ -38,6 +38,7 @@ upd4992_device::upd4992_device(const machine_config &mconfig, const char *tag, d
 	, device_rtc_interface(mconfig, *this)
 	, m_timer_clock(nullptr)
 {
+	std::fill(std::begin(m_rtc_regs), std::end(m_rtc_regs), 0);
 }
 
 
diff --git a/src/devices/video/jangou_blitter.cpp b/src/devices/video/jangou_blitter.cpp
index a866d13777d..326bf98fc6a 100644
--- a/src/devices/video/jangou_blitter.cpp
+++ b/src/devices/video/jangou_blitter.cpp
@@ -94,6 +94,7 @@ void jangou_blitter_device::device_reset()
 {
 	memset(m_pen_data, 0, ARRAY_LENGTH(m_pen_data));
 	m_bltflip = false;
+	m_src_addr = 0;
 }