From 22f330482b25cb02fa57ef1b6494a002452ac92b Mon Sep 17 00:00:00 2001
From: Wilbert Pol <wilbert@jdg.info>
Date: Sun, 30 Dec 2012 20:14:04 +0000
Subject: [PATCH] (MESS) odyssey2: Some small EF934x changes (nw)

---
 src/mess/includes/odyssey2.h |  4 ++
 src/mess/machine/odyssey2.c  | 16 ++++++++
 src/mess/video/odyssey2.c    | 74 ++++++++++++++++++++++++++++--------
 3 files changed, 79 insertions(+), 15 deletions(-)

diff --git a/src/mess/includes/odyssey2.h b/src/mess/includes/odyssey2.h
index 4a532809211..755fd50c436 100644
--- a/src/mess/includes/odyssey2.h
+++ b/src/mess/includes/odyssey2.h
@@ -117,6 +117,7 @@ public:
 	DECLARE_WRITE8_MEMBER(lum_write);
 	DECLARE_READ8_MEMBER(t1_read);
 	DECLARE_DRIVER_INIT(odyssey2);
+	virtual void machine_start();
 	virtual void machine_reset();
 	virtual void video_start();
 	void video_start_g7400();
@@ -132,10 +133,13 @@ protected:
 	ef9341_t m_ef9341;
 	UINT8	m_ef934x_ram_a[1024];
 	UINT8	m_ef934x_ram_b[1024];
+	UINT8	m_ef934x_ext_char_ram[1024];
 	bool	m_g7400;
 
 	inline UINT16 ef9340_get_c_addr();
 	inline void ef9340_inc_c();
+	// Calculate the external chargen address for a character and slice
+	inline UINT16 external_chargen_address(UINT8 b, UINT8 slice);
 
 	void i824x_scanline(int vpos);
 	void er9340_scanline(int vpos);
diff --git a/src/mess/machine/odyssey2.c b/src/mess/machine/odyssey2.c
index 80a752a055b..514309786e0 100644
--- a/src/mess/machine/odyssey2.c
+++ b/src/mess/machine/odyssey2.c
@@ -79,6 +79,22 @@ DRIVER_INIT_MEMBER(odyssey2_state,odyssey2)
 }
 
 
+void odyssey2_state::machine_start()
+{
+	save_item(NAME(m_ef934x_ram_a));
+	save_item(NAME(m_ef934x_ram_b));
+	save_item(NAME(m_ef9340.X));
+	save_item(NAME(m_ef9340.Y));
+	save_item(NAME(m_ef9340.Y0));
+	save_item(NAME(m_ef9340.R));
+	save_item(NAME(m_ef9340.M));
+	save_item(NAME(m_ef9341.TA));
+	save_item(NAME(m_ef9341.TB));
+	save_item(NAME(m_ef9341.busy));
+	save_item(NAME(m_ef934x_ext_char_ram));
+}
+
+
 void odyssey2_state::machine_reset()
 {
 	/* jump to "last" bank, will work for all sizes due to being mirrored */
diff --git a/src/mess/video/odyssey2.c b/src/mess/video/odyssey2.c
index 5b42931c032..db39f19e042 100644
--- a/src/mess/video/odyssey2.c
+++ b/src/mess/video/odyssey2.c
@@ -721,15 +721,32 @@ UINT16 odyssey2_state::ef9340_get_c_addr()
 	return ( m_ef9340.Y << 5 ) | m_ef9340.X;
 }
 
+
 void odyssey2_state::ef9340_inc_c()
 {
 	m_ef9340.X++;
 	if ( m_ef9340.X >= 40 )
 	{
 		m_ef9340.Y = ( m_ef9340.Y + 1 ) % 24;
+		m_ef9340.X = 0;
 	}
 }
 
+
+UINT16 odyssey2_state::external_chargen_address(UINT8 b, UINT8 slice)
+{
+	UINT8 cc = b & 0x7f;
+
+	if ( slice & 8 )
+	{
+		// 0 0 CCE4 CCE3 CCE2 CCE1 CCE0 CCE6 CCE5 ADR0
+		return ( ( cc << 3 ) & 0xf8 ) | ( ( cc >> 4 ) & 0x06) | ( slice & 0x01 );
+	}
+	// CCE6 CCE5 CCE4 CCE3 CCE2 CCE1 CCE0 ADR2 ADR1 ADR0
+	return  ( cc << 3 ) | ( slice & 0x07 );
+}
+
+
 void odyssey2_state::ef9341_w( UINT8 command, UINT8 b, UINT8 data )
 {
 	logerror("ef9341 %s write, t%s, data %02X\n", command ? "command" : "data", b ? "B" : "A", data );
@@ -776,24 +793,52 @@ void odyssey2_state::ef9341_w( UINT8 command, UINT8 b, UINT8 data )
 	{
 		if ( b )
 		{
+			UINT16 addr = ef9340_get_c_addr() & 0x3ff;
+
 			m_ef9341.TB = data;
 			m_ef9341.busy = 0x80;
 			switch ( m_ef9340.M & 0xE0 )
 			{
-			case 0x00:	/* Write */
-				m_ef934x_ram_b[ ef9340_get_c_addr() & 0x3ff ] = m_ef9341.TB;
-				ef9340_inc_c();
-				break;
-			case 0x20:	/* Read */
-				logerror("ef9341 unimplemented data action %02X\n", m_ef9340.M & 0xE0 );
-				ef9340_inc_c();
-				break;
-			case 0x40:	/* Write without increment */
-			case 0x60:	/* Read without increment */
-			case 0x80:	/* Write slice */
-			case 0xA0:	/* Read slice */
-				logerror("ef9341 unimplemented data action %02X\n", m_ef9340.M & 0xE0 );
-				break;
+				case 0x00:	/* Write */
+					m_ef934x_ram_a[addr] = m_ef9341.TA;
+					m_ef934x_ram_b[addr] = m_ef9341.TB;
+					ef9340_inc_c();
+					break;
+
+				case 0x20:	/* Read */
+					m_ef9341.TA = m_ef934x_ram_a[addr];
+					m_ef9341.TB = m_ef934x_ram_b[addr];
+					ef9340_inc_c();
+					break;
+
+				case 0x40:	/* Write without increment */
+					m_ef934x_ram_a[addr] = m_ef9341.TA;
+					m_ef934x_ram_b[addr] = m_ef9341.TB;
+					break;
+
+				case 0x60:	/* Read without increment */
+					m_ef9341.TA = m_ef934x_ram_a[addr];
+					m_ef9341.TB = m_ef934x_ram_b[addr];
+					break;
+
+				case 0x80:	/* Write slice */
+					{
+						UINT8 b = m_ef934x_ram_b[addr];
+						UINT8 slice = ( m_ef9340.M & 0x0f ) % 10;
+
+						if ( b >= 0xa0 )
+						{
+							m_ef934x_ext_char_ram[ external_chargen_address( b, slice ) ] = m_ef9341.TA;
+						}
+
+						// Increment slice number
+						m_ef9340.M = ( m_ef9340.M & 0xf0) | ( ( slice + 1 ) % 10 );
+					}
+					break;
+
+				case 0xA0:	/* Read slice */
+					fatalerror/*logerror*/("ef9341 unimplemented data action %02X\n", m_ef9340.M & 0xE0 );
+					break;
 			}
 			m_ef9341.busy = 0;
 		}
@@ -825,7 +870,6 @@ UINT8 odyssey2_state::ef9341_r( UINT8 command, UINT8 b )
 		if ( b )
 		{
 			data = m_ef9341.TB;
-			m_ef9341.busy = 0x80;
 		}
 		else
 		{