diff --git a/src/devices/cpu/vt50/vt50.cpp b/src/devices/cpu/vt50/vt50.cpp
index 346c057ecc9..c07d9b44014 100644
--- a/src/devices/cpu/vt50/vt50.cpp
+++ b/src/devices/cpu/vt50/vt50.cpp
@@ -556,7 +556,7 @@ void vt5x_cpu_device::execute_th(u8 inst)
 
 void vt52_cpu_device::execute_th(u8 inst)
 {
-	// not actually synchronized to TH
+	// not actually synchronized to TH (but may be gated externally with EN CYCLE)
 	if ((inst & 0362) == 0162)
 		m_graphic_callback(m_ram_do);
 
diff --git a/src/devices/cpu/vt50/vt50dasm.cpp b/src/devices/cpu/vt50/vt50dasm.cpp
index 6b450364b76..84e9f231fb3 100644
--- a/src/devices/cpu/vt50/vt50dasm.cpp
+++ b/src/devices/cpu/vt50/vt50dasm.cpp
@@ -42,7 +42,7 @@ const char *const vt50_disassembler::s_opcodes_g[8] = {
 };
 
 const char *const vt52_disassembler::s_opcodes_g[8] = {
-	"M2A", "A2M", "M2U", "B2M", "M2X", "U2M", "M2B", "GRAPHIC"
+	"M2A", "A2M", "M2U", "B2M", "M2X", "U2M", "M2B", "GRPH"
 };
 
 const char *const vt5x_disassembler::s_jumps_h[2][8] = {
diff --git a/src/mame/drivers/vt52.cpp b/src/mame/drivers/vt52.cpp
index a70a51b648e..110c7ebb03e 100644
--- a/src/mame/drivers/vt52.cpp
+++ b/src/mame/drivers/vt52.cpp
@@ -116,10 +116,12 @@ void vt52_state::vert_count_w(u8 data)
 			m_uart->write_tcp(clk);
 		}
 		else
+		{
 			m_uart->write_rcp((~(baud | data) & 0x0e) == 0);
+			m_uart->write_tcp((~(baud | data) & 0x71) == 0);
+		}
 	}
-
-	if ((baud & 0x0380) == 0x0380)
+	else if ((baud & 0x0380) == 0x0380)
 		m_uart->write_tcp((~(baud | data) & 0x71) == 0);
 }
 
@@ -325,7 +327,7 @@ void vt52_state::vt52(machine_config &mconfig)
 	screen.set_screen_update(FUNC(vt52_state::screen_update));
 
 	SPEAKER(mconfig, "mono").front_center();
-	SPEAKER_SOUND(mconfig, "bell").add_route(ALL_OUTPUTS, "mono", 1.0);
+	SPEAKER_SOUND(mconfig, "bell").add_route(ALL_OUTPUTS, "mono", 1.0); // FIXME: uses a flyback diode circuit
 }
 
 ROM_START(vt52)
@@ -339,4 +341,4 @@ ROM_START(vt52)
 	ROM_LOAD("23-002b4.e1", 0x000, 0x400, CRC(b486500c) SHA1(029f07424d6c23ee083db42d9f9c252ac728ccd0))
 ROM_END
 
-COMP(1975, vt52, 0, 0, vt52, vt52, vt52_state, empty_init, "Digital Equipment Corporation", "VT52 Video Display Terminal", MACHINE_NOT_WORKING)
+COMP(1975, vt52, 0, 0, vt52, vt52, vt52_state, empty_init, "Digital Equipment Corporation", "VT52 Video Display Terminal", MACHINE_NOT_WORKING | MACHINE_IMPERFECT_SOUND)