From e5d37a459596eaed3422f0741037cb7e4c116fd2 Mon Sep 17 00:00:00 2001
From: Wilbert Pol <wilbert@jdg.info>
Date: Sun, 7 Oct 2012 20:12:10 +0000
Subject: [PATCH] (MESS) a2600.c: Added proper support for games using a 4in1
 mapper.  (Wilbert Pol)

---
 hash/a2600.xml           |  6 +++++-
 src/mess/drivers/a2600.c | 11 +++++++++--
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/hash/a2600.xml b/hash/a2600.xml
index 5debf8e9d52..f61f556b6d0 100644
--- a/hash/a2600.xml
+++ b/hash/a2600.xml
@@ -217,6 +217,7 @@ Info from Atariage and Atarimania
 		<info name="serial" value="CX26137" /> <!-- Not Sure About it. -->
 		<sharedfeat name="compatibility" value="NTSC"/>
 		<part name="cart" interface="a2600_cart">
+			<feature name="mapper" value="4in1" />
 			<dataarea name="rom" size="8192">
 				<rom name="4 in 1 - canyon bomber, home run, night driver, sky diver (02-19-1987) (atari) (cx26137) (prototype).bin" size="8192" crc="8b304851" sha1="bc60987b668d6fa26c49f5aba5815622710140d9" offset="0" />
 			</dataarea>
@@ -230,17 +231,20 @@ Info from Atariage and Atarimania
 		<info name="serial" value="P460" />
 		<sharedfeat name="compatibility" value="PAL"/>
 		<part name="cart" interface="a2600_cart">
+			<feature name="mapper" value="4in1" />
 			<dataarea name="rom" size="16384">
 				<rom name="4 game in one - rodeo champ, open sesame, bobby is going home, festival.bin" size="16384" crc="69ca1a92" sha1="b6193826df511f39077013369e625e56577f2f36" offset="0" />
 			</dataarea>
 		</part>
 	</software>
 
-	<software name="4game1a" supported="no">
+	<software name="4game1a">
 		<description>4 Game in One - Ice Hockey + Phantom UFO + Spy Vs. Spy + Cosmic Avenger</description>
 		<year>198?</year>
 		<publisher>Bitcorp</publisher>
+		<sharedfeat name="compatibility" value="PAL"/>
 		<part name="cart" interface="a2600_cart">
+			<feature name="mapper" value="4in1" />
 			<dataarea name="rom" size="16384">
 				<rom name="4 game in one - ice hockey, phantom ufo, spy vs. spy, cosmic avenger.bin" size="16384" crc="caf86fa7" sha1="724c1ce352d0219699892f7c78083f825a71ac1a" offset="0" />
 			</dataarea>
diff --git a/src/mess/drivers/a2600.c b/src/mess/drivers/a2600.c
index db8bed6297a..36e1d4a266b 100644
--- a/src/mess/drivers/a2600.c
+++ b/src/mess/drivers/a2600.c
@@ -198,7 +198,8 @@ enum
 	modeDPC,
 	mode32in1,
 	modeJVP,
-	mode8in1
+	mode8in1,
+	mode4in1
 };
 
 static const UINT16 supported_screen_heights[4] = { 262, 312, 328, 342 };
@@ -609,7 +610,8 @@ static DEVICE_IMAGE_LOAD( a2600_cart )
 		{
 			static const struct { const char *mapper_name; int mapper_type; } mapper_types[] =
 			{
-				 { "8in1", mode8in1 },
+				{ "4in1", mode4in1 },
+				{ "8in1", mode8in1 },
 			};
 
 			for (int i = 0; i < ARRAY_LENGTH(mapper_types) && state->m_banking_mode == 0xff; i++)
@@ -1906,6 +1908,11 @@ void a2600_state::machine_reset()
 		install_banks(1, 0x0000);
 		break;
 
+	case mode4in1:
+		m_current_reset_bank_counter = m_current_reset_bank_counter & 0x03;
+		install_banks(1, m_current_reset_bank_counter * 0x1000);
+		break;
+
 	case mode8in1:
 		m_current_reset_bank_counter = m_current_reset_bank_counter & 0x07;
 		if ( m_current_reset_bank_counter == 7 )