t7000: Add some interrupts and video (pseudo) DMA

src/mame/wicat/t7000.cpp

@@ -10,6 +10,7 @@
 //#include "bus/rs232/rs232.h"
 #include "cpu/z80/z80.h"
 #include "machine/74259.h"
+#include "machine/input_merger.h"
 #include "machine/scn_pci.h"
 #include "machine/x2212.h"
 #include "video/i8275.h"
@@ -23,32 +24,96 @@ public:
 	t7000_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
 		, m_maincpu(*this, "maincpu")
+		, m_mainint(*this, "mainint")
+		, m_outlatch(*this, "outlatch")
 		, m_pci(*this, "pci%u", 0U)
 		, m_crtc(*this, "crtc%u", 0U)
+		, m_vram(*this, "vram")
+		, m_vram_view(*this, "vram")
 		, m_chargen(*this, "chargen")
+		, m_vblint(false)
 	{
 	}
 
 	void t7000(machine_config &config);
 
+protected:
+	virtual void machine_start() override;
+
 private:
 	I8275_DRAW_CHARACTER_MEMBER(display_character);
 
+	u8 vram_dma_r(offs_t offset);
+	u8 vblint_status_r();
+	void vblint_enable_w(int state);
+	void dma_enable_w(int state);
+	void vblint_w(int state);
 	void crtc_combined_w(offs_t offset, u8 data);
 
 	void mem_map(address_map &map);
 	void io_map(address_map &map);
 
 	required_device<cpu_device> m_maincpu;
+	required_device<input_merger_device> m_mainint;
+	required_device<ls259_device> m_outlatch;
 	required_device_array<scn_pci_device, 2> m_pci;
 	required_device_array<i8275_device, 2> m_crtc;
+	required_shared_ptr<u8> m_vram;
+	memory_view m_vram_view;
 	required_region_ptr<u8> m_chargen;
+
+	bool m_vblint;
 };
 
+void t7000_state::machine_start()
+{
+	save_item(NAME(m_vblint));
+}
+
 I8275_DRAW_CHARACTER_MEMBER(t7000_state::display_character)
 {
 }
 
+u8 t7000_state::vram_dma_r(offs_t offset)
+{
+	u8 data = m_vram[offset];
+	if (!machine().side_effects_disabled())
+		m_crtc[0]->dack_w(data);
+	return data;
+}
+
+u8 t7000_state::vblint_status_r()
+{
+	// Only bit 5 is ever examined
+	return m_vblint ? 0x20 : 0x00;
+}
+
+void t7000_state::vblint_enable_w(int state)
+{
+	if (!state && m_vblint)
+	{
+		m_vblint = false;
+		m_mainint->in_w<4>(0);
+	}
+}
+
+void t7000_state::dma_enable_w(int state)
+{
+	if (state)
+		m_vram_view.select(0);
+	else
+		m_vram_view.disable();
+}
+
+void t7000_state::vblint_w(int state)
+{
+	if (state && m_outlatch->q0_r() && !m_vblint)
+	{
+		m_vblint = true;
+		m_mainint->in_w<4>(1);
+	}
+}
+
 void t7000_state::crtc_combined_w(offs_t offset, u8 data)
 {
 	for (auto &crtc : m_crtc)
@@ -58,13 +123,17 @@ void t7000_state::crtc_combined_w(offs_t offset, u8 data)
 void t7000_state::mem_map(address_map &map)
 {
 	map(0x0000, 0x3fff).rom().region("program", 0);
-	map(0x4000, 0x7fff).ram();
+	map(0x4000, 0x7fff).ram().share(m_vram);
+	map(0x4000, 0x7fff).view(m_vram_view);
+	m_vram_view[0](0x4000, 0x7fff).r(FUNC(t7000_state::vram_dma_r));
 	map(0x8000, 0x803f).rw("novram", FUNC(x2210_device::read), FUNC(x2210_device::write));
 }
 
 void t7000_state::io_map(address_map &map)
 {
 	map.global_mask(0xff);
+	map(0x80, 0x80).r(FUNC(t7000_state::vblint_status_r));
+	map(0xa1, 0xa1).nopr(); // ?
 	map(0xb0, 0xb1).w(FUNC(t7000_state::crtc_combined_w));
 	map(0xb2, 0xb3).rw(m_crtc[0], FUNC(i8275_device::read), FUNC(i8275_device::write));
 	map(0xb4, 0xb5).rw(m_crtc[1], FUNC(i8275_device::read), FUNC(i8275_device::write));
@@ -83,13 +152,23 @@ void t7000_state::t7000(machine_config &config)
 	m_maincpu->set_addrmap(AS_PROGRAM, &t7000_state::mem_map);
 	m_maincpu->set_addrmap(AS_IO, &t7000_state::io_map);
 
+	INPUT_MERGER_ANY_HIGH(config, m_mainint).output_handler().set_inputline(m_maincpu, INPUT_LINE_IRQ0);
+	INPUT_MERGER_ALL_HIGH(config, "mainnmi").output_handler().set_inputline(m_maincpu, INPUT_LINE_NMI);
+
 	X2210(config, "novram"); // U39
 
 	SCN2651(config, m_pci[0], 5.0688_MHz_XTAL);
+	m_pci[0]->txrdy_handler().set(m_mainint, FUNC(input_merger_device::in_w<0>));
+	m_pci[0]->rxrdy_handler().set(m_mainint, FUNC(input_merger_device::in_w<1>));
 
 	SCN2651(config, m_pci[1], 5.0688_MHz_XTAL);
+	m_pci[1]->txrdy_handler().set(m_mainint, FUNC(input_merger_device::in_w<2>));
+	m_pci[1]->rxrdy_handler().set(m_mainint, FUNC(input_merger_device::in_w<3>));
 
-	LS259(config, "outlatch"); // U43
+	LS259(config, m_outlatch); // U43
+	m_outlatch->q_out_cb<0>().set(FUNC(t7000_state::vblint_enable_w));
+	m_outlatch->q_out_cb<1>().set(FUNC(t7000_state::dma_enable_w));
+	m_outlatch->q_out_cb<6>().set("mainnmi", FUNC(input_merger_device::in_w<0>));
 
 	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_RASTER));
 	screen.set_raw(19.6608_MHz_XTAL, 1020, 0, 800, 324, 0, 300);
@@ -98,6 +177,8 @@ void t7000_state::t7000(machine_config &config)
 	I8276(config, m_crtc[0], 19.6608_MHz_XTAL / 10);
 	m_crtc[0]->set_character_width(10);
 	m_crtc[0]->set_display_callback(FUNC(t7000_state::display_character));
+	m_crtc[0]->drq_wr_callback().set("mainnmi", FUNC(input_merger_device::in_w<1>));
+	m_crtc[0]->vrtc_wr_callback().set(FUNC(t7000_state::vblint_w));
 	m_crtc[0]->set_screen("screen");
 
 	I8276(config, m_crtc[1], 19.6608_MHz_XTAL / 10);