apricot: add an expansion slot interface and add two ram expansion

cards. this will also be usuable by the apricot f series and portable.

scripts/src/bus.lua

@@ -162,6 +162,23 @@ if (BUSES["APF"]~=null) then
 end
 
 
+---------------------------------------------------
+--
+--@src/emu/bus/apricot/expansion.h,BUSES += APRICOT_EXPANSION
+---------------------------------------------------
+
+if (BUSES["APRICOT_EXPANSION"]~=null) then
+	files {
+		MAME_DIR .. "src/emu/bus/apricot/expansion.c",
+		MAME_DIR .. "src/emu/bus/apricot/expansion.h",
+		MAME_DIR .. "src/emu/bus/apricot/cards.c",
+		MAME_DIR .. "src/emu/bus/apricot/cards.h",
+		MAME_DIR .. "src/emu/bus/apricot/ram.c",
+		MAME_DIR .. "src/emu/bus/apricot/ram.h",
+	}
+end
+
+
 ---------------------------------------------------
 --
 --@src/emu/bus/arcadia/slot.h,BUSES += ARCADIA

scripts/target/mame/mess.lua

@@ -572,6 +572,7 @@ BUSES["ABCKB"] = true
 BUSES["ADAM"] = true
 BUSES["ADAMNET"] = true
 BUSES["APF"] = true
+BUSES["APRICOT_EXPANSION"] = true
 BUSES["ARCADIA"] = true
 BUSES["ASTROCADE"] = true
 BUSES["BML3"] = true

src/emu/bus/apricot/cards.c

@@ -0,0 +1,14 @@
+// license:GPL-2.0+
+// copyright-holders:Dirk Best
+/***************************************************************************
+
+    ACT Apricot Expansion Slot Devices
+
+***************************************************************************/
+
+#include "cards.h"
+
+SLOT_INTERFACE_START( apricot_expansion_cards )
+	SLOT_INTERFACE("256k", APRICOT_256K_RAM)
+	SLOT_INTERFACE("128_512k", APRICOT_128_512K_RAM)
+SLOT_INTERFACE_END

src/emu/bus/apricot/cards.h

@@ -0,0 +1,19 @@
+// license:GPL-2.0+
+// copyright-holders:Dirk Best
+/***************************************************************************
+
+    ACT Apricot Expansion Slot Devices
+
+***************************************************************************/
+
+#pragma once
+
+#ifndef __APRICOT_CARDS_H__
+#define __APRICOT_CARDS_H__
+
+#include "emu.h"
+#include "ram.h"
+
+SLOT_INTERFACE_EXTERN( apricot_expansion_cards );
+
+#endif // __APRICOT_CARDS_H__

src/emu/bus/apricot/expansion.c

@@ -0,0 +1,166 @@
+// license:GPL-2.0+
+// copyright-holders:Dirk Best
+/***************************************************************************
+
+    ACT Apricot Expansion Slot
+
+***************************************************************************/
+
+#include "expansion.h"
+
+
+//**************************************************************************
+//  EXPANSION SLOT DEVICE
+//**************************************************************************
+
+const device_type APRICOT_EXPANSION_SLOT = &device_creator<apricot_expansion_slot_device>;
+
+//-------------------------------------------------
+//  apricot_expansion_slot_device - constructor
+//-------------------------------------------------
+
+apricot_expansion_slot_device::apricot_expansion_slot_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+	device_t(mconfig, APRICOT_EXPANSION_SLOT, "Apricot Expansion Slot", tag, owner, clock, "apricot_exp_slot", __FILE__),
+	device_slot_interface(mconfig, *this)
+{
+}
+
+apricot_expansion_slot_device::apricot_expansion_slot_device(const machine_config &mconfig, device_type type, const char *name,
+	const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source) :
+	device_t(mconfig, type, name, tag, owner, clock, shortname, source),
+	device_slot_interface(mconfig, *this)
+{
+}
+
+//-------------------------------------------------
+//  device_start - device-specific startup
+//-------------------------------------------------
+
+void apricot_expansion_slot_device::device_start()
+{
+	device_apricot_expansion_card_interface *dev = dynamic_cast<device_apricot_expansion_card_interface *>(get_card_device());
+
+	if (dev)
+	{
+		apricot_expansion_bus_device *bus = downcast<apricot_expansion_bus_device *>(m_owner);
+		bus->add_card(dev);
+	}
+}
+
+
+//**************************************************************************
+//  EXPANSION BUS DEVICE
+//**************************************************************************
+
+const device_type APRICOT_EXPANSION_BUS = &device_creator<apricot_expansion_bus_device>;
+
+//-------------------------------------------------
+//  apricot_expansion_bus_device - constructor
+//-------------------------------------------------
+
+apricot_expansion_bus_device::apricot_expansion_bus_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+	device_t(mconfig, APRICOT_EXPANSION_BUS, "Apricot Expansion Bus", tag, owner, clock, "apricot_exp_bus", __FILE__),
+	m_program(NULL),
+	m_io(NULL),
+	m_dma1_handler(*this),
+	m_dma2_handler(*this),
+	m_ext1_handler(*this),
+	m_ext2_handler(*this),
+	m_int2_handler(*this),
+	m_int3_handler(*this)
+{
+}
+
+//-------------------------------------------------
+//  apricot_expansion_bus_device - destructor
+//-------------------------------------------------
+
+apricot_expansion_bus_device::~apricot_expansion_bus_device()
+{
+	m_dev.detach_all();
+}
+
+//-------------------------------------------------
+//  device_start - device-specific startup
+//-------------------------------------------------
+
+void apricot_expansion_bus_device::device_start()
+{
+	// resolve callbacks
+	m_dma1_handler.resolve_safe();
+	m_dma2_handler.resolve_safe();
+	m_ext1_handler.resolve_safe();
+	m_ext2_handler.resolve_safe();
+	m_int2_handler.resolve_safe();
+	m_int3_handler.resolve_safe();
+}
+
+//-------------------------------------------------
+//  device_reset - device-specific reset
+//-------------------------------------------------
+
+void apricot_expansion_bus_device::device_reset()
+{
+	cpu_device *cpu = m_owner->subdevice<cpu_device>(m_cpu_tag);
+if (!cpu->started())
+	printf("cpu not running yet\n");
+	m_program = &cpu->space(AS_PROGRAM);
+	m_io = &cpu->space(AS_IO);
+}
+
+//-------------------------------------------------
+//  add_card - add new card to our bus
+//-------------------------------------------------
+
+void apricot_expansion_bus_device::add_card(device_apricot_expansion_card_interface *card)
+{
+	card->set_bus_device(this);
+	m_dev.append(*card);
+}
+
+//-------------------------------------------------
+//  set_cpu_tag - set cpu we are attached to
+//-------------------------------------------------
+
+void apricot_expansion_bus_device::set_cpu_tag(device_t &device, device_t *owner, const char *cpu_tag)
+{
+	apricot_expansion_bus_device &bus = dynamic_cast<apricot_expansion_bus_device &>(device);
+	bus.m_cpu_tag = cpu_tag;
+}
+
+// callbacks from slot device to the host
+WRITE_LINE_MEMBER( apricot_expansion_bus_device::dma1_w ) { m_dma1_handler(state); }
+WRITE_LINE_MEMBER( apricot_expansion_bus_device::dma2_w ) { m_dma2_handler(state); }
+WRITE_LINE_MEMBER( apricot_expansion_bus_device::ext1_w ) { m_ext1_handler(state); }
+WRITE_LINE_MEMBER( apricot_expansion_bus_device::ext2_w ) { m_ext2_handler(state); }
+WRITE_LINE_MEMBER( apricot_expansion_bus_device::int2_w ) { m_int2_handler(state); }
+WRITE_LINE_MEMBER( apricot_expansion_bus_device::int3_w ) { m_int3_handler(state); }
+
+
+//**************************************************************************
+//  CARTRIDGE INTERFACE
+//**************************************************************************
+
+//-------------------------------------------------
+//  device_apricot_expansion_card_interface - constructor
+//-------------------------------------------------
+
+device_apricot_expansion_card_interface::device_apricot_expansion_card_interface(const machine_config &mconfig, device_t &device) :
+	device_slot_card_interface(mconfig, device),
+	m_next(NULL),
+	m_bus(NULL)
+{
+}
+
+//-------------------------------------------------
+//  ~device_apricot_expansion_card_interface - destructor
+//-------------------------------------------------
+
+device_apricot_expansion_card_interface::~device_apricot_expansion_card_interface()
+{
+}
+
+void device_apricot_expansion_card_interface::set_bus_device(apricot_expansion_bus_device *bus)
+{
+	m_bus = bus;
+}

src/emu/bus/apricot/expansion.h

@@ -0,0 +1,198 @@
+// license:GPL-2.0+
+// copyright-holders:Dirk Best
+/***************************************************************************
+
+	ACT Apricot Expansion Slot
+
+       A          B
+
+	 -12V   32   +12V
+	  +5V   31   +5V
+	 DB0    30   DB1
+	 DB2    29   DB3
+	 DB4    28   DB5
+	 DB6    27   DB7
+	 AB10   26   AB9
+	 AB11   25   AB12
+	/AMWC   24   /MRDC
+	/DMA2   23   DT/R
+	/DMA1   22   /IORC
+	/MWTC   21   /RES
+	/IOWC   20   /AIOWC
+	  GND   19   GND
+	/CLK5   18   DEN
+	/IRDY   17   /MRDY
+	/EXT1   16   /EXT2
+	/INT3   15   /ALE
+	  AB6   14   /INT2
+	  AB8   13   AB7
+	  DB9   12   DB8
+	 DB11   11   DB10
+	 DB13   10   DB12
+	 DB15    9   DB14
+	  AB2    8   AB1
+	  AB4    7   AB3
+	  AB0    6   AB5
+	 AB14    5   AB13
+	 AB15    4   AB16
+	 AB17    3   AB18
+	 AB19    2   /BHE
+	  NMI    1   CLK15
+
+***************************************************************************/
+
+#pragma once
+
+#ifndef __APRICOT_EXPANSION_H__
+#define __APRICOT_EXPANSION_H__
+
+#include "emu.h"
+
+
+//**************************************************************************
+//  INTERFACE CONFIGURATION MACROS
+//**************************************************************************
+
+#define MCFG_EXPANSION_ADD(_tag, _cpu_tag) \
+	MCFG_DEVICE_ADD(_tag, APRICOT_EXPANSION_BUS, 0) \
+	apricot_expansion_bus_device::set_cpu_tag(*device, owner, _cpu_tag);
+
+#define MCFG_EXPANSION_SLOT_ADD(_tag, _slot_intf, _def_slot) \
+	MCFG_DEVICE_ADD(_tag, APRICOT_EXPANSION_SLOT, 0) \
+	MCFG_DEVICE_SLOT_INTERFACE(_slot_intf, _def_slot, false)
+
+#define MCFG_EXPANSION_DMA1_HANDLER(_devcb) \
+	devcb = &apricot_expansion_bus_device::set_dma1_handler(*device, DEVCB_##_devcb);
+
+#define MCFG_EXPANSION_DMA2_HANDLER(_devcb) \
+	devcb = &apricot_expansion_bus_device::set_dma2_handler(*device, DEVCB_##_devcb);
+
+#define MCFG_EXPANSION_EXT1_HANDLER(_devcb) \
+	devcb = &apricot_expansion_bus_device::set_ext1_handler(*device, DEVCB_##_devcb);
+
+#define MCFG_EXPANSION_EXT2_HANDLER(_devcb) \
+	devcb = &apricot_expansion_bus_device::set_ext2_handler(*device, DEVCB_##_devcb);
+
+#define MCFG_EXPANSION_INT2_HANDLER(_devcb) \
+	devcb = &apricot_expansion_bus_device::set_int2_handler(*device, DEVCB_##_devcb);
+
+#define MCFG_EXPANSION_INT3_HANDLER(_devcb) \
+	devcb = &apricot_expansion_bus_device::set_int3_handler(*device, DEVCB_##_devcb);
+
+
+//**************************************************************************
+//  TYPE DEFINITIONS
+//**************************************************************************
+
+// forward declaration
+class device_apricot_expansion_card_interface;
+
+
+// ======================> apricot_expansion_slot_device
+
+class apricot_expansion_slot_device : public device_t, public device_slot_interface
+{
+public:
+	// construction/destruction
+	apricot_expansion_slot_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+	apricot_expansion_slot_device(const machine_config &mconfig, device_type type, const char *name,
+		const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source);
+
+	// device-level overrides
+	virtual void device_start();
+};
+
+// device type definition
+extern const device_type APRICOT_EXPANSION_SLOT;
+
+
+// ======================> apricot_expansion_bus_device
+
+class apricot_expansion_bus_device : public device_t
+{
+public:
+	// construction/destruction
+	apricot_expansion_bus_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+	virtual ~apricot_expansion_bus_device();
+
+	template<class _Object> static devcb_base &set_dma1_handler(device_t &device, _Object object)
+		{ return downcast<apricot_expansion_bus_device &>(device).m_dma1_handler.set_callback(object); }
+
+	template<class _Object> static devcb_base &set_dma2_handler(device_t &device, _Object object)
+		{ return downcast<apricot_expansion_bus_device &>(device).m_dma2_handler.set_callback(object); }
+
+	template<class _Object> static devcb_base &set_ext1_handler(device_t &device, _Object object)
+		{ return downcast<apricot_expansion_bus_device &>(device).m_ext1_handler.set_callback(object); }
+
+	template<class _Object> static devcb_base &set_ext2_handler(device_t &device, _Object object)
+		{ return downcast<apricot_expansion_bus_device &>(device).m_ext2_handler.set_callback(object); }
+
+	template<class _Object> static devcb_base &set_int2_handler(device_t &device, _Object object)
+		{ return downcast<apricot_expansion_bus_device &>(device).m_int2_handler.set_callback(object); }
+
+	template<class _Object> static devcb_base &set_int3_handler(device_t &device, _Object object)
+		{ return downcast<apricot_expansion_bus_device &>(device).m_int3_handler.set_callback(object); }
+
+	// inline configuration
+	static void set_cpu_tag(device_t &device, device_t *owner, const char *cpu_tag);
+
+	void add_card(device_apricot_expansion_card_interface *card);
+
+	address_space *m_program;
+	address_space *m_io;
+
+	// from cards
+	DECLARE_WRITE_LINE_MEMBER( dma1_w );
+	DECLARE_WRITE_LINE_MEMBER( dma2_w );
+	DECLARE_WRITE_LINE_MEMBER( ext1_w );
+	DECLARE_WRITE_LINE_MEMBER( ext2_w );
+	DECLARE_WRITE_LINE_MEMBER( int2_w );
+	DECLARE_WRITE_LINE_MEMBER( int3_w );
+
+protected:
+	// device-level overrides
+	virtual void device_start();
+	virtual void device_reset();
+
+private:
+	simple_list<device_apricot_expansion_card_interface> m_dev;
+
+	devcb_write_line m_dma1_handler;
+	devcb_write_line m_dma2_handler;
+	devcb_write_line m_ext1_handler;
+	devcb_write_line m_ext2_handler;
+	devcb_write_line m_int2_handler;
+	devcb_write_line m_int3_handler;
+
+	// configuration
+	const char *m_cpu_tag;
+};
+
+// device type definition
+extern const device_type APRICOT_EXPANSION_BUS;
+
+
+// ======================> device_apricot_expansion_card_interface
+
+class device_apricot_expansion_card_interface : public device_slot_card_interface
+{
+public:
+	// construction/destruction
+	device_apricot_expansion_card_interface(const machine_config &mconfig, device_t &device);
+	virtual ~device_apricot_expansion_card_interface();
+
+	void set_bus_device(apricot_expansion_bus_device *bus);
+
+	device_apricot_expansion_card_interface *next() const { return m_next; }
+	device_apricot_expansion_card_interface *m_next;
+
+protected:
+	apricot_expansion_bus_device *m_bus;
+};
+
+
+// include here so drivers don't need to
+#include "cards.h"
+
+
+#endif // __APRICOT_EXPANSION_H__

src/emu/bus/apricot/ram.c

@@ -0,0 +1,141 @@
+// license:GPL-2.0+
+// copyright-holders:Dirk Best
+/***************************************************************************
+
+    ACT Apricot RAM Expansions
+
+***************************************************************************/
+
+#include "ram.h"
+
+
+//**************************************************************************
+//  DEVICE DEFINITIONS
+//**************************************************************************
+
+const device_type APRICOT_256K_RAM = &device_creator<apricot_256k_ram_device>;
+const device_type APRICOT_128_512K_RAM = &device_creator<apricot_128_512k_ram_device>;
+
+
+//**************************************************************************
+//  APRICOT 256K RAM DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+//  input_ports - device-specific input ports
+//-------------------------------------------------
+
+static INPUT_PORTS_START( apricot_256k )
+	PORT_START("sw")
+	PORT_DIPNAME(0x01, 0x00, "Base Address")
+	PORT_DIPSETTING(0x00, "40000H")
+	PORT_DIPSETTING(0x01, "80000H")
+INPUT_PORTS_END
+
+ioport_constructor apricot_256k_ram_device::device_input_ports() const
+{
+	return INPUT_PORTS_NAME( apricot_256k );
+}
+
+//-------------------------------------------------
+//  apricot_256k_ram_device - constructor
+//-------------------------------------------------
+
+apricot_256k_ram_device::apricot_256k_ram_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+	device_t(mconfig, APRICOT_256K_RAM, "Apricot 256K RAM Expansion Board", tag, owner, clock, "apricot_256k_ram", __FILE__),
+	device_apricot_expansion_card_interface(mconfig, *this),
+	m_sw(*this, "sw")
+{
+}
+
+//-------------------------------------------------
+//  device_start - device-specific startup
+//-------------------------------------------------
+
+void apricot_256k_ram_device::device_start()
+{
+	m_ram.resize(0x40000 / 2);
+}
+
+//-------------------------------------------------
+//  device_reset - device-specific reset
+//-------------------------------------------------
+
+void apricot_256k_ram_device::device_reset()
+{
+	if (m_sw->read() == 0)
+		m_bus->m_program->install_ram(0x40000, 0x7ffff, &m_ram[0]);
+	else
+		m_bus->m_program->install_ram(0x80000, 0xbffff, &m_ram[0]);
+}
+
+
+//**************************************************************************
+//  APRICOT 128/512K RAM DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+//  input_ports - device-specific input ports
+//-------------------------------------------------
+
+static INPUT_PORTS_START( apricot_128_512k )
+	PORT_START("config")
+	PORT_CONFNAME(0x01, 0x01, "DRAM Size")
+	PORT_CONFSETTING(0x00, "64K")
+	PORT_CONFSETTING(0x01, "256K")
+	PORT_START("strap")
+	PORT_DIPNAME(0x03, 0x00, "Base Address")
+	PORT_DIPSETTING(0x00, "512K")
+	PORT_DIPSETTING(0x01, "256K - 384K")
+	PORT_DIPSETTING(0x02, "384K - 512K")
+INPUT_PORTS_END
+
+ioport_constructor apricot_128_512k_ram_device::device_input_ports() const
+{
+	return INPUT_PORTS_NAME( apricot_128_512k );
+}
+
+//-------------------------------------------------
+//  apricot_128_512k_ram_device - constructor
+//-------------------------------------------------
+
+apricot_128_512k_ram_device::apricot_128_512k_ram_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+	device_t(mconfig, APRICOT_128_512K_RAM, "Apricot 128/512K RAM Expansion Board", tag, owner, clock, "apricot_128_512k_ram", __FILE__),
+	device_apricot_expansion_card_interface(mconfig, *this),
+	m_config(*this, "config"),
+	m_strap(*this, "strap")
+{
+}
+
+//-------------------------------------------------
+//  device_start - device-specific startup
+//-------------------------------------------------
+
+void apricot_128_512k_ram_device::device_start()
+{
+}
+
+//-------------------------------------------------
+//  device_reset - device-specific reset
+//-------------------------------------------------
+
+void apricot_128_512k_ram_device::device_reset()
+{
+	// 128 or 512k?
+	if (m_config->read() == 1)
+	{
+		m_ram.resize(0x80000 / 2);
+
+		if (m_strap->read() == 0)
+			m_bus->m_program->install_ram(0x40000, 0xbffff, &m_ram[0]);
+	}
+	else
+	{
+		m_ram.resize(0x20000 / 2);
+
+		if (m_strap->read() == 1)
+			m_bus->m_program->install_ram(0x40000, 0x5ffff, &m_ram[0]);
+		else if (m_strap->read() == 2)
+			m_bus->m_program->install_ram(0x60000, 0x7ffff, &m_ram[0]);
+	}
+}

src/emu/bus/apricot/ram.h

@@ -0,0 +1,69 @@
+// license:GPL-2.0+
+// copyright-holders:Dirk Best
+/***************************************************************************
+
+    ACT Apricot RAM Expansions
+
+***************************************************************************/
+
+#pragma once
+
+#ifndef __APRICOT_RAM__
+#define __APRICOT_RAM__
+
+#include "emu.h"
+#include "expansion.h"
+
+
+//**************************************************************************
+//  TYPE DEFINITIONS
+//**************************************************************************
+
+
+// ======================> apricot_256k_ram_device
+
+class apricot_256k_ram_device : public device_t, public device_apricot_expansion_card_interface
+{
+public:
+	// construction/destruction
+	apricot_256k_ram_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+protected:
+	virtual ioport_constructor device_input_ports() const;
+	virtual void device_start();
+	virtual void device_reset();
+
+private:
+	required_ioport m_sw;
+
+	std::vector<UINT16> m_ram;
+};
+
+
+// ======================> apricot_128_512k_ram_device
+
+class apricot_128_512k_ram_device : public device_t, public device_apricot_expansion_card_interface
+{
+public:
+	// construction/destruction
+	apricot_128_512k_ram_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+protected:
+	virtual ioport_constructor device_input_ports() const;
+	virtual void device_start();
+	virtual void device_reset();
+
+private:
+	required_ioport m_config;
+	required_ioport m_strap;
+
+	std::vector<UINT16> m_ram;
+};
+
+
+// device type definition
+extern const device_type APRICOT_256K_RAM;
+extern const device_type APRICOT_128_512K_RAM;
+
+
+#endif // __APRICOT_RAM__

src/mess/drivers/apricot.c

@@ -9,11 +9,8 @@
 
 ***************************************************************************/
 
-#include "bus/centronics/ctronics.h"
-#include "bus/rs232/rs232.h"
 #include "cpu/i86/i86.h"
 #include "cpu/i8089/i8089.h"
-#include "machine/ram.h"
 #include "machine/pit8253.h"
 #include "machine/i8255.h"
 #include "machine/pic8259.h"
@@ -23,6 +20,9 @@
 #include "sound/sn76496.h"
 #include "imagedev/flopdrv.h"
 #include "formats/apridisk.h"
+#include "bus/centronics/ctronics.h"
+#include "bus/rs232/rs232.h"
+#include "bus/apricot/expansion.h"
 
 
 //**************************************************************************
@@ -35,7 +35,6 @@ public:
 	apricot_state(const machine_config &mconfig, device_type type, const char *tag) :
 	driver_device(mconfig, type, tag),
 	m_cpu(*this, "ic91"),
-	m_ram(*this, RAM_TAG),
 	m_iop(*this, "ic71"),
 	m_sn(*this, "ic7"),
 	m_crtc(*this, "ic30"),
@@ -89,7 +88,6 @@ protected:
 
 private:
 	required_device<i8086_cpu_device> m_cpu;
-	required_device<ram_device> m_ram;
 	required_device<i8089_device> m_iop;
 	required_device<sn76489_device> m_sn;
 	required_device<mc6845_device> m_crtc;
@@ -262,14 +260,13 @@ UINT32 apricot_state::screen_update_apricot(screen_device &screen, bitmap_rgb32
 
 MC6845_UPDATE_ROW( apricot_state::crtc_update_row )
 {
-	UINT8 *ram = m_ram->pointer();
 	const pen_t *pen = m_palette->pens();
 
 	for (int i = 0; i < x_count; i++)
 	{
 		UINT16 code = m_screen_buffer[(ma + i) & 0x7ff];
 		UINT16 offset = ((code & 0x7ff) << 5) | (ra << 1);
-		UINT16 data = ram[offset + 1] << 8 | ram[offset];
+		UINT16 data = m_cpu->space(AS_PROGRAM).read_word(offset);
 
 		if (m_video_mode)
 		{
@@ -302,9 +299,6 @@ MC6845_UPDATE_ROW( apricot_state::crtc_update_row )
 
 void apricot_state::machine_start()
 {
-	// install shared memory to the main cpu and the iop
-	m_cpu->space(AS_PROGRAM).install_ram(0x00000, m_ram->size() - 1, m_ram->pointer());
-	m_iop->space(AS_PROGRAM).install_ram(0x00000, m_ram->size() - 1, m_ram->pointer());
 }
 
 IRQ_CALLBACK_MEMBER( apricot_state::irq_callback )
@@ -322,8 +316,7 @@ IRQ_CALLBACK_MEMBER( apricot_state::irq_callback )
 //**************************************************************************
 
 static ADDRESS_MAP_START( apricot_mem, AS_PROGRAM, 16, apricot_state )
-//  AM_RANGE(0x00000, 0x3ffff) AM_RAMBANK("standard_ram")
+	AM_RANGE(0x00000, 0x3ffff) AM_RAM
-//  AM_RANGE(0x40000, 0xeffff) AM_RAMBANK("expansion_ram")
 	AM_RANGE(0xf0000, 0xf0fff) AM_MIRROR(0x7000) AM_RAM AM_SHARE("screen_buffer")
 	AM_RANGE(0xfc000, 0xfffff) AM_MIRROR(0x4000) AM_ROM AM_REGION("bootstrap", 0)
 ADDRESS_MAP_END
@@ -382,11 +375,6 @@ static MACHINE_CONFIG_START( apricot, apricot_state )
 	MCFG_SOUND_ADD("ic7", SN76489, XTAL_4MHz / 2)
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 1.0)
 
-	// internal ram
-	MCFG_RAM_ADD(RAM_TAG)
-	MCFG_RAM_DEFAULT_SIZE("256k")
-	MCFG_RAM_EXTRA_OPTIONS("384k,512k") // with 1 or 2 128k expansion boards
-
 	// devices
 	MCFG_DEVICE_ADD("ic17", I8255A, 0)
 	MCFG_I8255_IN_PORTA_CB(DEVREAD8("cent_data_in", input_buffer_device, read))
@@ -441,6 +429,11 @@ static MACHINE_CONFIG_START( apricot, apricot_state )
 	MCFG_WD_FDC_DRQ_CALLBACK(DEVWRITELINE("ic71", i8089_device, drq1_w))
 	MCFG_FLOPPY_DRIVE_ADD("ic68:0", apricot_floppies, "d32w", apricot_state::floppy_formats)
 	MCFG_FLOPPY_DRIVE_ADD("ic68:1", apricot_floppies, "d32w", apricot_state::floppy_formats)
+
+	// expansion bus
+	MCFG_EXPANSION_ADD("exp", "ic91")
+	MCFG_EXPANSION_SLOT_ADD("exp:1", apricot_expansion_cards, NULL)
+	MCFG_EXPANSION_SLOT_ADD("exp:2", apricot_expansion_cards, NULL)
 MACHINE_CONFIG_END
 
 static MACHINE_CONFIG_DERIVED( apricotxi, apricot )