From 07591974578844a0fbe6ca8757e304d7dea83387 Mon Sep 17 00:00:00 2001
From: Curt Coder <curtcoder@mail.com>
Date: Tue, 24 Apr 2018 22:46:04 +0300
Subject: [PATCH] vic10: Implemented MultiMAX cartridge. [Curt Coder]

---
 hash/vic10.xml                     | 10 +++----
 src/devices/bus/vic10/multimax.cpp | 42 +++++++++++++++++++++++++++++-
 src/devices/bus/vic10/multimax.h   |  4 +++
 3 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/hash/vic10.xml b/hash/vic10.xml
index 115fef67556..4b3c804eb00 100644
--- a/hash/vic10.xml
+++ b/hash/vic10.xml
@@ -322,16 +322,16 @@
 		</part>
 	</software>
 
-	<software name="multimax" supported="no">
-		<description>MultiMax</description>
+	<software name="multimax">
+		<description>MultiMAX</description>
 		<year>2014</year>
 		<publisher>Rob Clarke &amp; Michal Pleban</publisher>
-
-		<part name="cart" interface="c64_cart">
+		<part name="cart" interface="vic10_cart">
 			<feature name="slot" value="multimax" />
-			<dataarea name="roml" size="0x100000">
+			<dataarea name="lorom" size="0x100000">
 				<rom name="multimax.bin" size="0x100000" crc="4853de57" sha1="1d8b0b111af7cbd1e4bffd58d4c22d8f49de3741" offset="0x0000" />
 			</dataarea>
+			<dataarea name="exram" size="0x800" />
 		</part>
 	</software>
 
diff --git a/src/devices/bus/vic10/multimax.cpp b/src/devices/bus/vic10/multimax.cpp
index de197530004..3ab9ae80ad9 100644
--- a/src/devices/bus/vic10/multimax.cpp
+++ b/src/devices/bus/vic10/multimax.cpp
@@ -28,7 +28,8 @@ DEFINE_DEVICE_TYPE(MULTIMAX, multimax_t, "multimax", "MultiMAX Cartridge")
 //-------------------------------------------------
 
 multimax_t::multimax_t(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
-	device_t(mconfig, MULTIMAX, tag, owner, clock), device_vic10_expansion_card_interface(mconfig, *this)
+	device_t(mconfig, MULTIMAX, tag, owner, clock), device_vic10_expansion_card_interface(mconfig, *this),
+	m_latch(0)
 {
 }
 
@@ -39,6 +40,18 @@ multimax_t::multimax_t(const machine_config &mconfig, const char *tag, device_t
 
 void multimax_t::device_start()
 {
+	// state saving
+	save_item(NAME(m_latch));
+}
+
+
+//-------------------------------------------------
+//  device_reset - device-specific reset
+//-------------------------------------------------
+
+void multimax_t::device_reset()
+{
+	m_latch = 0;
 }
 
 
@@ -48,6 +61,22 @@ void multimax_t::device_start()
 
 uint8_t multimax_t::vic10_cd_r(address_space &space, offs_t offset, uint8_t data, int lorom, int uprom, int exram)
 {
+	if (!lorom)
+	{
+		data = m_lorom[((m_latch & 0x3f) << 14) | (offset & 0x1fff)];
+	}
+	else if (!uprom)
+	{
+		data = m_lorom[((m_latch & 0x3f) << 14) | 0x2000 | (offset & 0x1fff)];
+	}
+	else if (!exram)
+	{
+		if (m_latch)
+		{
+			data = m_exram[offset & 0x7ff];
+		}
+	}
+
 	return data;
 }
 
@@ -58,4 +87,15 @@ uint8_t multimax_t::vic10_cd_r(address_space &space, offs_t offset, uint8_t data
 
 void multimax_t::vic10_cd_w(address_space &space, offs_t offset, uint8_t data, int lorom, int uprom, int exram)
 {
+	if (!exram)
+	{
+		if (m_latch)
+		{
+			m_exram[offset & 0x7ff] = data;
+		}
+		else
+		{
+			m_latch = data;
+		}
+	}
 }
diff --git a/src/devices/bus/vic10/multimax.h b/src/devices/bus/vic10/multimax.h
index 96d8cf54213..ae4cfa968d1 100644
--- a/src/devices/bus/vic10/multimax.h
+++ b/src/devices/bus/vic10/multimax.h
@@ -31,10 +31,14 @@ public:
 protected:
 	// device-level overrides
 	virtual void device_start() override;
+	virtual void device_reset() override;
 
 	// device_vic10_expansion_card_interface overrides
 	virtual uint8_t vic10_cd_r(address_space &space, offs_t offset, uint8_t data, int lorom, int uprom, int exram) override;
 	virtual void vic10_cd_w(address_space &space, offs_t offset, uint8_t data, int lorom, int uprom, int exram) override;
+
+private:
+	uint8_t m_latch;
 };