gnat10: Fill in a few more things (nw)

src/mame/drivers/gnat10.cpp

@@ -2,15 +2,17 @@
 // copyright-holders:AJR
 /****************************************************************************
 
-    Skeleton driver for CP/M system by GNAT Computers.
+    Skeleton driver for CP/M system by GNAT Computers, Inc.
 
-    For more information, visit the following link:
+    For more background on this company, visit the following link:
     https://classictech.wordpress.com/computer-companies/gnat-computers-san-diego-calif/
 
 ****************************************************************************/
 
 #include "emu.h"
 #include "cpu/z80/z80.h"
+#include "imagedev/floppy.h"
+#include "machine/com8116.h"
 #include "machine/wd_fdc.h"
 #include "machine/z80sio.h"
 
@@ -21,63 +23,141 @@ public:
 		: driver_device(mconfig, type, tag)
 		, m_maincpu(*this, "maincpu")
 		, m_fdc(*this, "fdc")
+		, m_floppy(*this, "fdc:%u", 0U)
+		, m_brg(*this, "brg")
+		, m_monitor(*this, "monitor")
+		, m_ram(*this, "ram")
+		, m_ram_on(false)
 	{
 	}
 
 	void gnat10(machine_config &config);
 
+protected:
+	virtual void machine_start() override;
+	virtual void machine_reset() override;
+
 private:
+	u8 ram_r(offs_t offset);
 	u8 floppy_status_r();
+	void floppy_latch_w(u8 data);
+	void baud0_w(u8 data);
+	void baud1_w(u8 data);
 
 	void mem_map(address_map &map);
 	void io_map(address_map &map);
 
 	required_device<cpu_device> m_maincpu;
-	required_device<fd1797_device> m_fdc;
+	required_device<fd1793_device> m_fdc;
+	required_device_array<floppy_connector, 2> m_floppy;
+	required_device<com8116_device> m_brg;
+	required_region_ptr<u8> m_monitor;
+	required_shared_ptr<u8> m_ram;
+
+	bool m_ram_on;
 };
 
+void gnat10_state::machine_start()
+{
+	save_item(NAME(m_ram_on));
+}
+
+void gnat10_state::machine_reset()
+{
+	m_ram_on = false;
+	floppy_latch_w(0);
+}
+
+
+u8 gnat10_state::ram_r(offs_t offset)
+{
+	if (m_ram_on)
+		return m_ram[offset];
+	else
+		return m_monitor[offset & 0x07ff];
+}
 
 u8 gnat10_state::floppy_status_r()
 {
 	return m_fdc->drq_r() << 7 | m_fdc->intrq_r();
 }
 
+void gnat10_state::floppy_latch_w(u8 data)
+{
+	// D0 = DS1, D1 = DS2, D5 = SS
+	floppy_image_device *floppy = nullptr;
+	for (int i = 0; i < 2 && floppy == nullptr; i++)
+		if (BIT(data, i))
+			floppy = m_floppy[i]->get_device();
+	m_fdc->set_floppy(floppy);
+	if (floppy != nullptr)
+		floppy->ss_w(BIT(data, 5));
+
+	m_fdc->mr_w(BIT(data, 7));
+}
+
+void gnat10_state::baud0_w(u8 data)
+{
+	m_brg->str_w(data & 0x0f);
+	m_ram_on = true;
+}
+
+void gnat10_state::baud1_w(u8 data)
+{
+	m_brg->stt_w((data & 0xf0) >> 4);
+}
+
 void gnat10_state::mem_map(address_map &map)
 {
-	map(0x0000, 0x0002).rom().region("boot", 0);
+	map(0x0000, 0xf7ff).r(FUNC(gnat10_state::ram_r)).writeonly().share("ram");
-	map(0x0003, 0xf7ff).ram();
+	map(0xf800, 0xffff).rom().region("monitor", 0);
-	map(0xf800, 0xffff).rom().region("boot", 0);
 }
 
 void gnat10_state::io_map(address_map &map)
 {
 	map.global_mask(0xff);
 	map(0x60, 0x63).rw("sio1", FUNC(z80sio_device::ba_cd_r), FUNC(z80sio_device::ba_cd_w));
-	map(0x70, 0x73).rw("sio2", FUNC(z80sio_device::ba_cd_r), FUNC(z80sio_device::ba_cd_w));
+	map(0x70, 0x73).rw("sio0", FUNC(z80sio_device::ba_cd_r), FUNC(z80sio_device::ba_cd_w));
-	map(0x80, 0x83).rw(m_fdc, FUNC(fd1797_device::read), FUNC(fd1797_device::write));
+	map(0x80, 0x83).rw(m_fdc, FUNC(fd1793_device::read), FUNC(fd1793_device::write));
-	map(0xa0, 0xa0).r(FUNC(gnat10_state::floppy_status_r));
+	map(0xa0, 0xa0).rw(FUNC(gnat10_state::floppy_status_r), FUNC(gnat10_state::floppy_latch_w));
+	map(0xd0, 0xd0).w(FUNC(gnat10_state::baud0_w));
+	map(0xe0, 0xe0).w(FUNC(gnat10_state::baud1_w));
 }
 
 
 static INPUT_PORTS_START(gnat10)
 INPUT_PORTS_END
 
+static void gnat_floppies(device_slot_interface &device)
+{
+	device.option_add("525qd", FLOPPY_525_QD);
+}
+
 void gnat10_state::gnat10(machine_config &config)
 {
-	Z80(config, m_maincpu, 4'000'000);
+	Z80(config, m_maincpu, 16_MHz_XTAL / 4);
 	m_maincpu->set_addrmap(AS_PROGRAM, &gnat10_state::mem_map);
 	m_maincpu->set_addrmap(AS_IO, &gnat10_state::io_map);
 
-	Z80SIO(config, "sio1", 4'000'000); // type unknown
+	Z80SIO(config, "sio0", 16_MHz_XTAL / 4); // MK3884
-	Z80SIO(config, "sio2", 4'000'000); // type unknown
+	Z80SIO(config, "sio1", 16_MHz_XTAL / 4);
 
-	FD1797(config, m_fdc, 1'000'000); // type unknown
+	FD1793(config, m_fdc, 16_MHz_XTAL / 16);
+	FLOPPY_CONNECTOR(config, m_floppy[0], gnat_floppies, "525qd", floppy_image_device::default_floppy_formats);
+	FLOPPY_CONNECTOR(config, m_floppy[1], gnat_floppies, "525qd", floppy_image_device::default_floppy_formats);
+
+	COM5016_5(config, m_brg, 4.9152_MHz_XTAL); // specific type unknown
+	m_brg->fr_handler().set("sio0", FUNC(z80sio_device::rxca_w));
+	m_brg->fr_handler().append("sio0", FUNC(z80sio_device::txca_w));
+	m_brg->fr_handler().append("sio1", FUNC(z80sio_device::rxca_w));
+	m_brg->fr_handler().append("sio1", FUNC(z80sio_device::txca_w));
+	m_brg->ft_handler().set("sio1", FUNC(z80sio_device::rxtxcb_w));
 
 	// TODO: video screen, peripheral ports
 }
 
 ROM_START(gnat10)
-	ROM_REGION(0x800, "boot", 0)
+	ROM_REGION(0x800, "monitor", 0)
 	ROM_LOAD("gnat-507", 0x000, 0x800, CRC(72baa750) SHA1(7b78324b90b8c6f78c88a7dde8d53ea612ea1f7f)) // LF patched back to CR/LF in four instances
 ROM_END