From 937ebdc8240a9c35adefd553259cfcd3f55cf55d Mon Sep 17 00:00:00 2001
From: "R. Belmont" <rb6502@users.noreply.github.com>
Date: Tue, 1 Jul 2014 02:29:36 +0000
Subject: [PATCH] (MESS) Apple II: Add volume control register to DX-1 card.
 [R. Belmont]

---
 src/emu/bus/a2bus/a2dx1.c | 9 ++++++++-
 src/emu/bus/a2bus/a2dx1.h | 3 +++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/emu/bus/a2bus/a2dx1.c b/src/emu/bus/a2bus/a2dx1.c
index 68f1ef87158..cb4b191e8c0 100644
--- a/src/emu/bus/a2bus/a2dx1.c
+++ b/src/emu/bus/a2bus/a2dx1.c
@@ -70,10 +70,14 @@ void a2bus_dx1_device::device_start()
 {
 	// set_a2bus_device makes m_slot valid
 	set_a2bus_device();
+
+	save_item(NAME(m_volume));
+	save_item(NAME(m_lastdac));
 }
 
 void a2bus_dx1_device::device_reset()
 {
+	m_volume = m_lastdac = 0;
 }
 
 UINT8 a2bus_dx1_device::read_c0nx(address_space &space, UINT8 offset)
@@ -98,10 +102,13 @@ void a2bus_dx1_device::write_c0nx(address_space &space, UINT8 offset, UINT8 data
 	switch (offset)
 	{
 		case 5:	// volume
+			m_volume = data;
+			m_dac->write_unsigned16(data*m_lastdac);
 			break;
 
 		case 6:
-			m_dac->write_unsigned8(data);
+			m_lastdac = data;
+			m_dac->write_unsigned16(data*m_volume);
 			break;
 	}
 }
diff --git a/src/emu/bus/a2bus/a2dx1.h b/src/emu/bus/a2bus/a2dx1.h
index 970a1b56810..99b9d98193a 100644
--- a/src/emu/bus/a2bus/a2dx1.h
+++ b/src/emu/bus/a2bus/a2dx1.h
@@ -41,6 +41,9 @@ protected:
 	virtual UINT8 read_c0nx(address_space &space, UINT8 offset);
 	virtual void write_c0nx(address_space &space, UINT8 offset, UINT8 data);
 	virtual bool take_c800();
+
+private:
+	UINT8 m_volume, m_lastdac;
 };
 
 // device type definition