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r32156 Wednesday 17th September, 2014 at 17:24:53 UTC by Fabio Priuli
(MESS) a2600.c: fixed mapper 3E support, as used by Boulder Dash homebrew. Also allowed bankswitch writes to get to the TIA for this and mapper 3F. Finally, included a couple of demos in the softlist so to be able to test the code in future. nw.

[hash]	a2600.xml
[src/emu/bus/vcs]	rom.c
[src/mess/drivers]	a2600.c

trunk/hash/a2600.xml

r32155	r32156
18400	18400	</dataarea>
18401	18401	</part>
18402	18402	</software>
	18403
	18404
	18405	<!-- Since the released cart is undumped, let us include at least these demos to test 3E bankswitch code -->
	18406	<software name="bdash">
	18407	<description>Boulder Dash (Demo v2)</description>
	18408	<year>2014</year>
	18409	<publisher>&lt;homebrew&gt;</publisher>
	18410	<part name="cart" interface="a2600_cart">
	18411	<feature name="slot" value="a26_3e" />
	18412	<dataarea name="rom" size="32768">
	18413	<rom name="boulder dash (demo 2).bin" size="32768" crc="2f7b6112" sha1="adcb4b38413ad6851a1562cacd376dbf25a4dd00" offset="0" />
	18414	</dataarea>
	18415	<dataarea name="ram" size="32768">
	18416	</dataarea>
	18417	</part>
	18418	</software>
	18419
	18420	<software name="bdash1" cloneof="bdash">
	18421	<description>Boulder Dash (Demo v1)</description>
	18422	<year>2011</year>
	18423	<publisher>&lt;homebrew&gt;</publisher>
	18424	<part name="cart" interface="a2600_cart">
	18425	<feature name="slot" value="a26_3e" />
	18426	<dataarea name="rom" size="32768">
	18427	<rom name="boulderdash100.bin" size="32768" crc="9ba60c62" sha1="660360ee11ab442d5f9db44848d3c0c99ee61e1c" offset="0" />
	18428	</dataarea>
	18429	<dataarea name="ram" size="32768">
	18430	</dataarea>
	18431	</part>
	18432	</software>
18403	18433	</softwarelist>

trunk/src/emu/bus/vcs/rom.c

r32155	r32156
678	678
679	679	READ8_MEMBER(a26_rom_3e_device::read_rom)
680	680	{
681		if (m_ram && m_ram_enable && offset >= 0x400 && offset < 0x600)
682		{
683		offset -= 0x400;
684		return m_ram[offset + (m_ram_bank * 0x200)];
685		}
	681	if (m_ram && m_ram_enable && offset < 0x400)
	682	return m_ram[offset + (m_ram_bank * 0x400)];
686	683
687	684	if (offset >= 0x800)
688		return m_rom[offset + (m_num_bank - 1) * 0x800];
	685	return m_rom[(offset & 0x7ff) + (m_num_bank - 1) * 0x800];
689	686	else
690	687	return m_rom[offset + m_base_bank * 0x800];
691	688	}
692	689
693	690	WRITE8_MEMBER(a26_rom_3e_device::write_bank)
694	691	{
695		if (offset)   // 0x3f
	692	if (offset == 0x3f)
696	693	{
697	694	m_base_bank = data & (m_num_bank - 1);
698	695	m_ram_enable = 0;
699	696	}
700		else   // 0x3e
	697	else if (offset == 0x3e)
701	698	{
702		m_ram_bank = data & 0x3f;
	699	m_ram_bank = data & 0x1f;
703	700	m_ram_enable = 1;
704	701	}
705	702	}
706	703
707	704	WRITE8_MEMBER(a26_rom_3e_device::write_ram)
708	705	{
709		if (m_ram && m_ram_enable && offset >= 0x400 && offset < 0x600)
710		{
711		offset -= 0x400;
712		m_ram[offset + (m_ram_bank * 0x200)] = data;
713		}
	706	if (m_ram && m_ram_enable && offset >= 0x400 && offset < 0x800)
	707	m_ram[(offset & 0x3ff) + (m_ram_bank * 0x400)] = data;
714	708	}
715	709
	710
716	711	/*-------------------------------------------------
717	712	"3F Bankswitch" Carts:
718	713	write access to 0x00-0x3f determines the 2K ROM bank

trunk/src/mess/drivers/a2600.c

r32155	r32156
33	33	m_joy1(*this, CONTROL1_TAG),
34	34	m_joy2(*this, CONTROL2_TAG) ,
35	35	m_cartslot(*this, "cartslot"),
	36	m_tia(*this, "tia_video"),
36	37	m_maincpu(*this, "maincpu"),
37	38	m_screen(*this, "screen") { }
38	39
r32155	r32156
49	50	DECLARE_READ8_MEMBER(a2600_get_databus_contents);
50	51	DECLARE_WRITE16_MEMBER(a2600_tia_vsync_callback);
51	52	DECLARE_WRITE16_MEMBER(a2600_tia_vsync_callback_pal);
	53	DECLARE_WRITE8_MEMBER(cart_over_tia_w);
52	54	// investigate how the carts mapped here (Mapper JVP) interact with the RIOT device
53	55	DECLARE_READ8_MEMBER(cart_over_riot_r);
54	56	DECLARE_WRITE8_MEMBER(cart_over_riot_w);
r32155	r32156
57	59	required_device<vcs_control_port_device> m_joy1;
58	60	required_device<vcs_control_port_device> m_joy2;
59	61	required_device<vcs_cart_slot_device> m_cartslot;
	62	required_device<tia_video_device> m_tia;
60	63
61	64	unsigned long detect_2600controllers();
62	65	required_device<m6502_device> m_maincpu;
r32155	r32156
246	249
247	250	}
248	251
	252	WRITE8_MEMBER(a2600_state::cart_over_tia_w)
	253	{
	254	// Both Cart & TIA see these addresses
	255	if (m_cartslot)
	256	m_cartslot->write_bank(space, offset, data);
	257
	258	m_tia->write(space, offset, data);
	259	}
	260
249	261	MACHINE_START_MEMBER(a2600_state,a2600)
250	262	{
251	263	m_current_screen_height = m_screen->height();
r32155	r32156
279	291	break;
280	292	case A26_3E:
281	293	m_maincpu->space(AS_PROGRAM).install_readwrite_handler(0x1000, 0x1fff, read8_delegate(FUNC(vcs_cart_slot_device::read_rom),(vcs_cart_slot_device*)m_cartslot), write8_delegate(FUNC(vcs_cart_slot_device::write_ram),(vcs_cart_slot_device*)m_cartslot));
282		m_maincpu->space(AS_PROGRAM).install_write_handler(0x3e, 0x3f, write8_delegate(FUNC(vcs_cart_slot_device::write_bank),(vcs_cart_slot_device*)m_cartslot));
	294	m_maincpu->space(AS_PROGRAM).install_write_handler(0x00, 0x3f, write8_delegate(FUNC(a2600_state::cart_over_tia_w), this));
283	295	break;
284	296	case A26_3F:
285	297	m_maincpu->space(AS_PROGRAM).install_read_handler(0x1000, 0x1fff, read8_delegate(FUNC(vcs_cart_slot_device::read_rom),(vcs_cart_slot_device*)m_cartslot));
286		m_maincpu->space(AS_PROGRAM).install_write_handler(0x00, 0x3f, write8_delegate(FUNC(vcs_cart_slot_device::write_bank),(vcs_cart_slot_device*)m_cartslot));
	298	m_maincpu->space(AS_PROGRAM).install_write_handler(0x00, 0x3f, write8_delegate(FUNC(a2600_state::cart_over_tia_w), this));
287	299	break;
288	300	case A26_UA:
289	301	m_maincpu->space(AS_PROGRAM).install_read_handler(0x1000, 0x1fff, read8_delegate(FUNC(vcs_cart_slot_device::read_rom),(vcs_cart_slot_device*)m_cartslot));

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