From d4ab3c5549e54c58c6a0ba40453016572add8591 Mon Sep 17 00:00:00 2001
From: Nigel Barnes <Pernod70@users.noreply.github.com>
Date: Sat, 11 May 2019 17:11:38 +0100
Subject: [PATCH] coco12.cpp: Added handlers for CTS region $C000-$FEFF, allows
 cartridges to implement devices in this region.

---
 src/devices/bus/coco/cococart.cpp | 53 ++++++++++++++++++++++++++++++-
 src/devices/bus/coco/cococart.h   |  6 ++++
 src/mame/machine/coco12.cpp       |  5 +--
 3 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/src/devices/bus/coco/cococart.cpp b/src/devices/bus/coco/cococart.cpp
index 6bf6360d24b..6932629e746 100644
--- a/src/devices/bus/coco/cococart.cpp
+++ b/src/devices/bus/coco/cococart.cpp
@@ -151,6 +151,30 @@ void cococart_slot_device::device_timer(emu_timer &timer, device_timer_id id, in
 }
 
 
+//-------------------------------------------------
+//  cts_read
+//-------------------------------------------------
+
+READ8_MEMBER(cococart_slot_device::cts_read)
+{
+	uint8_t result = 0x00;
+	if (m_cart)
+		result = m_cart->cts_read(space, offset);
+	return result;
+}
+
+
+//-------------------------------------------------
+//  cts_write
+//-------------------------------------------------
+
+WRITE8_MEMBER(cococart_slot_device::cts_write)
+{
+	if (m_cart)
+		m_cart->cts_write(space, offset, data);
+}
+
+
 //-------------------------------------------------
 //  scs_read
 //-------------------------------------------------
@@ -412,7 +436,7 @@ image_init_result cococart_slot_device::call_load()
 	{
 		memory_region *cart_mem = m_cart->get_cart_memregion();
 		uint8_t *base = cart_mem->base();
-		offs_t read_length, cart_length = cart_mem->bytes();;
+		offs_t read_length, cart_length = cart_mem->bytes();
 
 		if (!loaded_through_softlist())
 		{
@@ -501,6 +525,33 @@ void device_cococart_interface::interface_pre_start()
 }
 
 
+//-------------------------------------------------
+//  cts_read - Signifies a read where the CTS pin
+//  on the cartridge slot was asserted ($C000-FFEF)
+//-------------------------------------------------
+
+READ8_MEMBER(device_cococart_interface::cts_read)
+{
+	memory_region *cart_mem = get_cart_memregion();
+	offs_t cart_length = cart_mem->bytes();
+
+	if (cart_mem)
+		return cart_mem->base()[offset & (cart_length - 1)];
+	else
+		return 0x00;
+}
+
+
+//-------------------------------------------------
+//  cts_write - Signifies a write where the CTS pin
+//  on the cartridge slot was asserted ($C000-FFEF)
+//-------------------------------------------------
+
+WRITE8_MEMBER(device_cococart_interface::cts_write)
+{
+}
+
+
 //-------------------------------------------------
 //  scs_read - Signifies a read where the SCS pin
 //  on the cartridge slot was asserted ($FF40-5F)
diff --git a/src/devices/bus/coco/cococart.h b/src/devices/bus/coco/cococart.h
index c559a2eea53..bcee3d2990a 100644
--- a/src/devices/bus/coco/cococart.h
+++ b/src/devices/bus/coco/cococart.h
@@ -88,6 +88,10 @@ public:
 	// slot interface overrides
 	virtual std::string get_default_card_software(get_default_card_software_hook &hook) const override;
 
+	// reading and writing to $C000-$FFEF
+	DECLARE_READ8_MEMBER(cts_read);
+	DECLARE_WRITE8_MEMBER(cts_write);
+
 	// reading and writing to $FF40-$FF5F
 	DECLARE_READ8_MEMBER(scs_read);
 	DECLARE_WRITE8_MEMBER(scs_write);
@@ -161,6 +165,8 @@ public:
 	// construction/destruction
 	virtual ~device_cococart_interface();
 
+	virtual DECLARE_READ8_MEMBER(cts_read);
+	virtual DECLARE_WRITE8_MEMBER(cts_write);
 	virtual DECLARE_READ8_MEMBER(scs_read);
 	virtual DECLARE_WRITE8_MEMBER(scs_write);
 	virtual void set_sound_enable(bool sound_enable);
diff --git a/src/mame/machine/coco12.cpp b/src/mame/machine/coco12.cpp
index da49aad2c2f..c6d858efbaf 100644
--- a/src/mame/machine/coco12.cpp
+++ b/src/mame/machine/coco12.cpp
@@ -30,12 +30,13 @@ void coco12_state::device_start()
 void coco12_state::configure_sam()
 {
 	uint8_t *rom = memregion(MAINCPU_TAG)->base();
-	uint8_t *cart_rom = cococart().get_cart_base();
 
 	m_sam->configure_bank(0, ram().pointer(), ram().size(), false); // $0000-$7FFF
 	m_sam->configure_bank(1, &rom[0x0000], 0x2000, true);           // $8000-$9FFF
 	m_sam->configure_bank(2, &rom[0x2000], 0x2000, true);           // $A000-$BFFF
-	m_sam->configure_bank(3, cart_rom, 0x4000, true);               // $C000-$FEFF
+
+	// $C000-$FEFF
+	m_sam->configure_bank(3, read8_delegate(FUNC(cococart_slot_device::cts_read), m_cococart.target()), write8_delegate(FUNC(cococart_slot_device::cts_write), m_cococart.target()));
 
 	// $FF00-$FF1F
 	m_sam->configure_bank(4, read8_delegate(FUNC(coco12_state::ff00_read), this), write8_delegate(FUNC(coco12_state::ff00_write), this));