Emulation of Games Master Cartridge

scripts/src/bus.lua

@@ -2496,6 +2496,8 @@ if (BUSES["COCO"]~=null) then
 		MAME_DIR .. "src/devices/bus/coco/coco_pak.h",
 		MAME_DIR .. "src/devices/bus/coco/coco_fdc.cpp",
 		MAME_DIR .. "src/devices/bus/coco/coco_fdc.h",
+		MAME_DIR .. "src/devices/bus/coco/coco_gmc.cpp",
+		MAME_DIR .. "src/devices/bus/coco/coco_gmc.h",
 		MAME_DIR .. "src/devices/bus/coco/coco_multi.cpp",
 		MAME_DIR .. "src/devices/bus/coco/coco_multi.h",
 		MAME_DIR .. "src/devices/bus/coco/coco_dwsock.cpp",

src/devices/bus/coco/coco_gmc.cpp

@@ -0,0 +1,73 @@
+// license:BSD-3-Clause
+// copyright-holders:tim lindner
+/***************************************************************************
+
+    coco_gmc.c
+
+    Code for emulating the Games Master Cartridge. A banked switched ROM
+    cartridge with a SN76489AN programmable sound generator.
+
+    The ROM bank switching is exactly like the circuit developed for RoboCop
+    and Predator.
+
+    The SN76489AN is tied to address $FF41.
+
+    Cartridge by John Linville.
+
+***************************************************************************/
+
+#include "emu.h"
+#include "coco_gmc.h"
+#include "speaker.h"
+
+#define SN76489AN_TAG   "gmc_psg"
+
+static MACHINE_CONFIG_FRAGMENT(cocopak_gmc)
+	MCFG_SPEAKER_STANDARD_MONO("gmc_speaker")
+	MCFG_SOUND_ADD(SN76489AN_TAG, SN76489A, XTAL_4MHz)
+	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "gmc_speaker", 1.0)
+MACHINE_CONFIG_END
+
+//**************************************************************************
+//  GLOBAL VARIABLES
+//**************************************************************************
+
+const device_type COCO_PAK_GMC = device_creator<coco_pak_gmc_device>;
+
+//-------------------------------------------------
+//  coco_pak_device - constructor
+//-------------------------------------------------
+
+coco_pak_gmc_device::coco_pak_gmc_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+		: coco_pak_banked_device(mconfig, tag, owner, clock),
+		m_psg(*this, SN76489AN_TAG)
+{
+}
+
+//-------------------------------------------------
+//  machine_config_additions - device-specific
+//  machine configurations
+//-------------------------------------------------
+
+machine_config_constructor coco_pak_gmc_device::device_mconfig_additions() const
+{
+	return MACHINE_CONFIG_NAME( cocopak_gmc );
+}
+
+/*-------------------------------------------------
+    write
+-------------------------------------------------*/
+
+WRITE8_MEMBER(coco_pak_gmc_device::write)
+{
+	switch(offset)
+	{
+		case 0:
+			/* set the bank */
+			coco_pak_banked_device::write(space,offset,data,mem_mask);
+			break;
+		case 1:
+			m_psg->write(data);
+			break;
+	}
+}

src/devices/bus/coco/coco_gmc.h

@@ -0,0 +1,31 @@
+// license:BSD-3-Clause
+// copyright-holders:tim lindner
+#pragma once
+
+#ifndef __COCO_GMC_H__
+#define __COCO_GMC_H__
+
+#include "coco_pak.h"
+#include "sound/sn76496.h"
+
+// ======================> coco_pak_banked_device
+
+class coco_pak_gmc_device :
+		public coco_pak_banked_device
+{
+public:
+		// construction/destruction
+		coco_pak_gmc_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
+		virtual machine_config_constructor device_mconfig_additions() const override;
+
+protected:
+		// device-level overrides
+		virtual DECLARE_WRITE8_MEMBER(write) override;
+private:
+		required_device<sn76489a_device> m_psg;
+};
+
+
+// device type definition
+extern const device_type COCO_PAK_GMC;
+#endif  /* __COCO_GMC_H__ */

src/devices/bus/coco/coco_multi.cpp

@@ -57,6 +57,7 @@
 #include "coco_multi.h"
 #include "coco_232.h"
 #include "coco_orch90.h"
+#include "coco_gmc.h"
 #include "coco_pak.h"
 #include "coco_fdc.h"
 
@@ -74,6 +75,7 @@
 static SLOT_INTERFACE_START(coco_cart_slot1_3)
 	SLOT_INTERFACE("rs232", COCO_232)
 	SLOT_INTERFACE("orch90", COCO_ORCH90)
+	SLOT_INTERFACE("games_master", COCO_PAK_GMC)
 	SLOT_INTERFACE("banked_16k", COCO_PAK_BANKED)
 	SLOT_INTERFACE("pak", COCO_PAK)
 SLOT_INTERFACE_END
@@ -82,6 +84,7 @@ static SLOT_INTERFACE_START(coco_cart_slot4)
 	SLOT_INTERFACE("fdcv11", COCO_FDC_V11)
 	SLOT_INTERFACE("rs232", COCO_232)
 	SLOT_INTERFACE("orch90", COCO_ORCH90)
+	SLOT_INTERFACE("games_master", COCO_PAK_GMC)
 	SLOT_INTERFACE("banked_16k", COCO_PAK_BANKED)
 	SLOT_INTERFACE("pak", COCO_PAK)
 SLOT_INTERFACE_END

src/mame/drivers/coco12.cpp

@@ -31,6 +31,7 @@
 #include "bus/coco/coco_fdc.h"
 #include "bus/coco/coco_multi.h"
 #include "bus/coco/coco_orch90.h"
+#include "bus/coco/coco_gmc.h"
 #include "bus/coco/coco_pak.h"
 #include "bus/coco/coco_t4426.h"
 
@@ -252,6 +253,7 @@ SLOT_INTERFACE_START( coco_cart )
 	SLOT_INTERFACE("cp400_fdc", CP400_FDC)
 	SLOT_INTERFACE("rs232", COCO_232)
 	SLOT_INTERFACE("orch90", COCO_ORCH90)
+	SLOT_INTERFACE("games_master", COCO_PAK_GMC)
 	SLOT_INTERFACE("banked_16k", COCO_PAK_BANKED)
 	SLOT_INTERFACE("pak", COCO_PAK)
 	SLOT_INTERFACE("multi", COCO_MULTIPAK) MCFG_SLOT_OPTION_CLOCK("multi", DERIVED_CLOCK(1, 1))

src/mame/drivers/dragon.cpp

@@ -16,6 +16,7 @@
 #include "cpu/m6809/m6809.h"
 #include "bus/coco/coco_232.h"
 #include "bus/coco/coco_orch90.h"
+#include "bus/coco/coco_gmc.h"
 #include "bus/coco/coco_pak.h"
 #include "bus/coco/coco_fdc.h"
 #include "bus/coco/coco_multi.h"