d'oh. sorry.

.gitattributes

@@ -479,6 +479,8 @@ src/emu/bus/a2bus/timemasterho.h svneol=native#text/plain
 src/emu/bus/a7800/a78_carts.h svneol=native#text/plain
 src/emu/bus/a7800/a78_slot.c svneol=native#text/plain
 src/emu/bus/a7800/a78_slot.h svneol=native#text/plain
+src/emu/bus/a7800/cpuwiz.c svneol=native#text/plain
+src/emu/bus/a7800/cpuwiz.h svneol=native#text/plain
 src/emu/bus/a7800/hiscore.c svneol=native#text/plain
 src/emu/bus/a7800/hiscore.h svneol=native#text/plain
 src/emu/bus/a7800/rom.c svneol=native#text/plain

src/emu/bus/a7800/cpuwiz.c

@@ -0,0 +1,158 @@
+/***********************************************************************************************************
+
+ A7800 CPUWIZ's homebrew boards (MegaCart+ and VersaBoard)
+ 
+ Here we emulate the base configurations of these two boards:
+
+ MegaCart+ = up to 512K (31 banks at $8000, 1 at $C000) of ROM and 2 x 16K RAM @ $4000
+ VersaBoard = up to 256K of ROM and 2 x 16K RAM
+ 
+ Plus, for the moment, a VersaBoard with POKEY mapped at 0x0450 and support for 144K ROM, 
+ since a few demo homebrew programs seems to use this to combine compatibility with 
+ XBoarD & XM expansions
+
+ Note that the VersaBoard can be configured to work with different banking hardware
+ e.g. with SG 9bank games or with SG + RAM (so to allow reproduction of games which
+ could have worked on old carts without sacrifying original carts), but games running 
+ on those "standard" variants can be emulated with the standard code from rom.c ;-)
+ 
+ 
+ TO DO:
+ - investigate whether the POKEY detection routines in homebrew do fail due to emulation
+   issues or not
+ 
+***********************************************************************************************************/
+
+
+#include "emu.h"
+#include "cpuwiz.h"
+
+
+//-------------------------------------------------
+//  constructor
+//-------------------------------------------------
+
+const device_type A78_ROM_VERSABOARD = &device_creator<a78_versaboard_device>;
+const device_type A78_ROM_VERSAPOKEY = &device_creator<a78_versapokey_device>;
+const device_type A78_ROM_MEGACART = &device_creator<a78_megacart_device>;
+
+
+a78_versaboard_device::a78_versaboard_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)
+					: a78_rom_sg_device(mconfig, type, name, tag, owner, clock, shortname, source)
+{
+}
+
+a78_versaboard_device::a78_versaboard_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+					: a78_rom_sg_device(mconfig, A78_ROM_VERSABOARD, "Atari 7800 VersaBoard Cart", tag, owner, clock, "a78_versaboard", __FILE__)
+{
+}
+
+a78_versapokey_device::a78_versapokey_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+					: a78_versaboard_device(mconfig, A78_ROM_VERSAPOKEY, "Atari 7800 VersaBoard + POKEY @ 0x0450 Cart", tag, owner, clock, "a78_versapokey", __FILE__),
+						m_pokey(*this, "pokey")
+{
+}
+
+a78_megacart_device::a78_megacart_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+					: a78_versaboard_device(mconfig, A78_ROM_MEGACART, "Atari 7800 MegaCart+", tag, owner, clock, "a78_megacart", __FILE__)
+{
+}
+
+
+void a78_versaboard_device::device_start()
+{
+	save_item(NAME(m_bank));
+	save_item(NAME(m_ram_bank));
+}
+
+void a78_versaboard_device::device_reset()
+{
+	m_bank = 0;
+	m_ram_bank = 0;
+}
+
+
+// VersaBoard
+
+READ8_MEMBER(a78_versaboard_device::read_40xx)
+{
+	if (offset < 0x4000)
+		return m_ram[offset + (m_ram_bank * 0x4000)];
+	else if (offset < 0x8000)
+		return m_rom[(offset & 0x3fff) + (m_bank * 0x4000)];
+	else
+		return m_rom[(offset & 0x3fff) + (m_bank_mask * 0x4000)];	// last bank
+}
+
+WRITE8_MEMBER(a78_versaboard_device::write_40xx)
+{
+	if (offset < 0x4000)
+		m_ram[offset + (m_ram_bank * 0x4000)] = data;
+	else if (offset < 0x8000)
+	{
+		// hardware allows up to 256K ROM
+		m_bank = (data & 0x0f) & m_bank_mask;
+		m_ram_bank = BIT(data, 5);
+	}
+}
+
+
+// VersaBoard + POKEY @ 0x0450
+
+static MACHINE_CONFIG_FRAGMENT( a78_pokey )
+	MCFG_SPEAKER_STANDARD_MONO("addon")
+
+	MCFG_SOUND_ADD("pokey", POKEY, XTAL_14_31818MHz/8)
+	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "addon", 1.00)
+MACHINE_CONFIG_END
+
+machine_config_constructor a78_versapokey_device::device_mconfig_additions() const
+{
+	return MACHINE_CONFIG_NAME( a78_pokey );
+}
+
+READ8_MEMBER(a78_versapokey_device::read_04xx)
+{
+	if (offset >= 0x50 && offset < 0x60)
+		return m_pokey->read(space, offset & 0x0f);
+	else
+		return 0xff;
+}
+
+WRITE8_MEMBER(a78_versapokey_device::write_04xx)
+{
+	if (offset >= 0x50 && offset < 0x60)
+		m_pokey->write(space, offset & 0x0f, data);
+}
+
+READ8_MEMBER(a78_versapokey_device::read_40xx)
+{
+	if (offset < 0x4000)
+		return m_rom[(offset & 0x3fff)];
+	else if (offset < 0x8000)
+		return m_rom[(offset & 0x3fff) + (m_bank * 0x4000)];
+	else
+		return m_rom[(offset & 0x3fff) + ((m_bank_mask + 1) * 0x4000)];	// last bank
+}
+
+WRITE8_MEMBER(a78_versapokey_device::write_40xx)
+{
+	if (offset >= 0x4000 && offset < 0x8000)
+		m_bank = (data & m_bank_mask) + 1;
+}
+
+
+// MegaCart+
+
+WRITE8_MEMBER(a78_megacart_device::write_40xx)
+{
+	if (offset < 0x4000)
+		m_ram[offset + (m_ram_bank * 0x4000)] = data;
+	else if (offset < 0x8000)
+	{
+		// hardware allows up to 512K ROM
+		m_bank = (data & 0x1f) & m_bank_mask;
+		m_ram_bank = BIT(data, 5);
+	}
+}
+

src/emu/bus/a7800/cpuwiz.h

@@ -0,0 +1,72 @@
+#ifndef __A78_CPUWIZ_H
+#define __A78_CPUWIZ_H
+
+#include "a78_slot.h"
+#include "rom.h"
+
+
+// ======================> a78_versaboard_device
+
+class a78_versaboard_device : public a78_rom_sg_device
+{
+public:
+	// construction/destruction
+	a78_versaboard_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);
+	a78_versaboard_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+	
+	// device-level overrides
+	virtual void device_start();
+	virtual void device_reset();
+	
+	// reading and writing
+	virtual DECLARE_READ8_MEMBER(read_40xx);
+	virtual DECLARE_WRITE8_MEMBER(write_40xx);
+	
+protected:
+	int m_ram_bank;
+};
+
+
+// ======================> a78_versapokey_device
+
+class a78_versapokey_device : public a78_versaboard_device
+{
+public:
+	// construction/destruction
+	a78_versapokey_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+	
+	// device-level overrides
+	virtual machine_config_constructor device_mconfig_additions() const;
+	
+	// reading and writing
+	virtual DECLARE_READ8_MEMBER(read_04xx);
+	virtual DECLARE_WRITE8_MEMBER(write_04xx);
+	virtual DECLARE_READ8_MEMBER(read_40xx);
+	virtual DECLARE_WRITE8_MEMBER(write_40xx);
+
+protected:
+	required_device<pokey_device> m_pokey;
+};
+
+
+// ======================> a78_megacart_device
+
+class a78_megacart_device : public a78_versaboard_device
+{
+public:
+	// construction/destruction
+	a78_megacart_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+	
+	// reading and writing
+	virtual DECLARE_WRITE8_MEMBER(write_40xx);
+};
+
+
+
+// device type definition
+extern const device_type A78_ROM_VERSABOARD;
+extern const device_type A78_ROM_VERSAPOKEY;
+extern const device_type A78_ROM_MEGACART;
+
+
+#endif