From 37c2d0587d5c27ab699dad1e58a722d5e043b40f Mon Sep 17 00:00:00 2001
From: smf- <smf-@users.noreply.github.com>
Date: Sun, 6 Apr 2014 08:48:33 +0000
Subject: [PATCH] added RS232 loopback [smf]

---
 .gitattributes               |  2 ++
 src/emu/bus/bus.mak          |  1 +
 src/emu/bus/rs232/loopback.c | 16 ++++++++++++++++
 src/emu/bus/rs232/loopback.h | 25 +++++++++++++++++++++++++
 src/emu/bus/rs232/rs232.c    |  4 +++-
 5 files changed, 47 insertions(+), 1 deletion(-)
 create mode 100644 src/emu/bus/rs232/loopback.c
 create mode 100644 src/emu/bus/rs232/loopback.h

diff --git a/.gitattributes b/.gitattributes
index 6592e49cf83..cd08a4b90b3 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1160,6 +1160,8 @@ src/emu/bus/plus4/user.c svneol=native#text/plain
 src/emu/bus/plus4/user.h svneol=native#text/plain
 src/emu/bus/rs232/keyboard.c svneol=native#text/plain
 src/emu/bus/rs232/keyboard.h svneol=native#text/plain
+src/emu/bus/rs232/loopback.c svneol=native#text/plain
+src/emu/bus/rs232/loopback.h svneol=native#text/plain
 src/emu/bus/rs232/null_modem.c svneol=native#text/plain
 src/emu/bus/rs232/null_modem.h svneol=native#text/plain
 src/emu/bus/rs232/rs232.c svneol=native#text/plain
diff --git a/src/emu/bus/bus.mak b/src/emu/bus/bus.mak
index e95447ba6fc..70cefb05ddb 100644
--- a/src/emu/bus/bus.mak
+++ b/src/emu/bus/bus.mak
@@ -703,6 +703,7 @@ endif
 ifneq ($(filter RS232,$(BUSES)),)
 OBJDIRS += $(BUSOBJ)/rs232
 BUSOBJS += $(BUSOBJ)/rs232/keyboard.o
+BUSOBJS += $(BUSOBJ)/rs232/loopback.o
 BUSOBJS += $(BUSOBJ)/rs232/null_modem.o
 BUSOBJS += $(BUSOBJ)/rs232/rs232.o
 BUSOBJS += $(BUSOBJ)/rs232/ser_mouse.o
diff --git a/src/emu/bus/rs232/loopback.c b/src/emu/bus/rs232/loopback.c
new file mode 100644
index 00000000000..4cd97f8adb2
--- /dev/null
+++ b/src/emu/bus/rs232/loopback.c
@@ -0,0 +1,16 @@
+// license:MAME
+// copyright-holders:smf
+
+#include "loopback.h"
+
+const device_type RS232_LOOPBACK = &device_creator<rs232_loopback_device>;
+
+rs232_loopback_device::rs232_loopback_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+	: device_t(mconfig, RS232_LOOPBACK, "RS232 Loopback", tag, owner, clock, "rs232_loopback", __FILE__),
+	device_rs232_port_interface(mconfig, *this)
+{
+}
+
+void rs232_loopback_device::device_start()
+{
+}
diff --git a/src/emu/bus/rs232/loopback.h b/src/emu/bus/rs232/loopback.h
new file mode 100644
index 00000000000..3459a7bf1c2
--- /dev/null
+++ b/src/emu/bus/rs232/loopback.h
@@ -0,0 +1,25 @@
+// license:MAME
+// copyright-holders:smf
+
+#ifndef RS232_LOOPBACK_H_
+#define RS232_LOOPBACK_H_
+
+#include "bus/rs232/rs232.h"
+
+class rs232_loopback_device : public device_t,
+	public device_rs232_port_interface
+{
+public:
+	rs232_loopback_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+	virtual WRITE_LINE_MEMBER( input_txd ) { output_rxd(state); }
+	virtual WRITE_LINE_MEMBER( input_rts ) { output_ri(state); output_cts(state); }
+	virtual WRITE_LINE_MEMBER( input_dtr ) { output_dsr(state); output_dcd(state); }
+
+protected:
+	virtual void device_start();
+};
+
+extern const device_type RS232_LOOPBACK;
+
+#endif
diff --git a/src/emu/bus/rs232/rs232.c b/src/emu/bus/rs232/rs232.c
index eeff291621a..74f5c371b22 100644
--- a/src/emu/bus/rs232/rs232.c
+++ b/src/emu/bus/rs232/rs232.c
@@ -96,10 +96,12 @@ device_rs232_port_interface::~device_rs232_port_interface()
 {
 }
 
+#include "loopback.h"
 #include "null_modem.h"
 #include "terminal.h"
 
 SLOT_INTERFACE_START( default_rs232_devices )
-	SLOT_INTERFACE("serial_terminal", SERIAL_TERMINAL)
+	SLOT_INTERFACE("loopback", SERIAL_LOOPBACK)
 	SLOT_INTERFACE("null_modem", NULL_MODEM)
+	SLOT_INTERFACE("serial_terminal", SERIAL_TERMINAL)
 SLOT_INTERFACE_END