Added a skeleton for the DEC DC7085 (aka "DZ") quad UART. [R. Belmont]

scripts/src/machine.lua

@@ -3843,3 +3843,15 @@ if (MACHINES["AIC6250"]~=null) then
 		MAME_DIR .. "src/devices/machine/aic6250.h",
 	}
 end
+
+---------------------------------------------------
+--
+--@src/devices/machine/dc7085.h,MACHINES["DC7085"] = true
+---------------------------------------------------
+
+if (MACHINES["DC7085"]~=null) then
+	files {
+		MAME_DIR .. "src/devices/machine/dc7085.cpp",
+		MAME_DIR .. "src/devices/machine/dc7085.h",
+	}
+end

scripts/target/mame/mess.lua

@@ -678,6 +678,7 @@ MACHINES["IOPSIO2"] = true
 MACHINES["IOPTIMER"] = true
 MACHINES["Z8038"] = true
 MACHINES["AIC6250"] = true
+MACHINES["DC7085"] = true
 
 --------------------------------------------------
 -- specify available bus cores

src/devices/machine/dc7085.cpp

@@ -0,0 +1,87 @@
+// license:BSD-3-Clause
+// copyright-holders:R. Belmont
+
+/*
+ * An emulation of the Digital Equipment Corporation DC7085 (also called "DZ") quad-UART
+ *
+ * Used in:
+ *
+ *   Several models of MIPS DECstation
+ *   Some VAXstations
+ *
+ * Sources:
+ *
+ *   http://www.vanade.com/~blc/DS3100/pmax/DS3100.func.spec.pdf
+ *
+ */
+
+#include "emu.h"
+#include "dc7085.h"
+
+#define LOG_GENERAL (1U << 0)
+#define LOG_REG     (1U << 1)
+
+//#define VERBOSE (LOG_GENERAL|LOG_REG)
+
+#include "logmacro.h"
+
+DEFINE_DEVICE_TYPE(DC7085, dc7085_device, "dc7085", "Digital Equipment Corporation DC7085 Quad UART")
+
+dc7085_device::dc7085_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+	: device_t(mconfig, DC7085, tag, owner, clock),
+	m_int_cb(*this)
+{
+}
+
+void dc7085_device::map(address_map &map)
+{
+	map(0x00, 0x01).rw(FUNC(dc7085_device::status_r), FUNC(dc7085_device::control_w));
+	map(0x04, 0x05).rw(FUNC(dc7085_device::rxbuffer_r), FUNC(dc7085_device::lineparams_w));
+	map(0x10, 0x11).rw(FUNC(dc7085_device::txparams_r), FUNC(dc7085_device::txparams_w));
+	map(0x14, 0x15).rw(FUNC(dc7085_device::modem_status_r), FUNC(dc7085_device::txdata_w));
+}
+
+void dc7085_device::device_start()
+{
+	m_int_cb.resolve_safe();
+}
+
+void dc7085_device::device_reset()
+{
+}
+
+u16 dc7085_device::status_r()
+{
+	return 0x8000;
+}
+
+u16 dc7085_device::rxbuffer_r()
+{
+	return 0;
+}
+
+u16 dc7085_device::txparams_r()
+{
+	return 0;
+}
+
+u16 dc7085_device::modem_status_r()
+{
+	return 0;
+}
+
+void dc7085_device::control_w(u16 data)
+{
+}
+
+void dc7085_device::lineparams_w(u16 data)
+{
+}
+
+void dc7085_device::txparams_w(u16 data)
+{
+}
+
+void dc7085_device::txdata_w(u16 data)
+{
+}

src/devices/machine/dc7085.h

@@ -0,0 +1,38 @@
+// license:BSD-3-Clause
+// copyright-holders:R. Belmont
+
+#ifndef MAME_MACHINE_DC7085_H
+#define MAME_MACHINE_DC7085_H
+
+#pragma once
+
+class dc7085_device : public device_t
+{
+public:
+	dc7085_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
+
+	void map(address_map &map);
+
+	auto int_cb() { return m_int_cb.bind(); }
+
+protected:
+	// standard device_interface overrides
+	virtual void device_start() override;
+	virtual void device_reset() override;
+
+	devcb_write_line m_int_cb;
+
+	u16 status_r();
+	u16 rxbuffer_r();
+	u16 txparams_r();
+	u16 modem_status_r();
+	void control_w(u16 data);
+	void lineparams_w(u16 data);
+	void txparams_w(u16 data);
+	void txdata_w(u16 data);
+private:
+};
+
+DECLARE_DEVICE_TYPE(DC7085, dc7085_device)
+
+#endif // MAME_MACHINE_DC7085_H

src/mame/drivers/decstation.cpp

@@ -69,6 +69,7 @@
 #include "machine/nscsi_hd.h"
 #include "machine/dec_lk201.h"
 #include "machine/am79c90.h"
+#include "machine/dc7085.h"
 #include "bus/rs232/rs232.h"
 #include "screen.h"
 #include "video/bt459.h"
@@ -90,7 +91,8 @@ public:
 		m_vrom(*this, "gfx"),
 		m_bt459(*this, "bt459"),
 		m_lance(*this, "am79c90"),
-		m_kn01vram(*this, "vram")
+		m_kn01vram(*this, "vram"),
+		m_dz(*this, "dc7085")
 		{ }
 
 	void kn01(machine_config &config);
@@ -140,6 +142,7 @@ private:
 	optional_device<bt459_device> m_bt459;
 	required_device<am79c90_device> m_lance;
 	optional_shared_ptr<uint32_t> m_kn01vram;
+	optional_device<dc7085_device> m_dz;
 
 	void kn01_map(address_map &map);
 	void threemin_map(address_map &map);
@@ -600,7 +603,7 @@ void decstation_state::kn01_map(address_map &map)
 	map(0x11000000, 0x1100003f).rw(FUNC(decstation_state::pcc_r), FUNC(decstation_state::pcc_w));
 	map(0x12000000, 0x1200001f).rw(FUNC(decstation_state::bt478_palette_r), FUNC(decstation_state::bt478_palette_w));
 	//map(0x18000000, 0x18000007).rw(m_lance, FUNC(am79c90_device::regs_r), FUNC(am79c90_device::regs_w)).umask32(0x0000ffff);
-	map(0x1c000000, 0x1c000003).r(FUNC(decstation_state::dz_r));
+	map(0x1c000000, 0x1c00001b).m(m_dz, FUNC(dc7085_device::map)).umask32(0xffff);
 	map(0x1d000000, 0x1d0000ff).rw(m_rtc, FUNC(mc146818_device::read_direct), FUNC(mc146818_device::write_direct)).umask32(0x000000ff);
 	map(0x1e000000, 0x1effffff).rw(FUNC(decstation_state::kn01_status_r), FUNC(decstation_state::kn01_control_w));
 	map(0x1fc00000, 0x1fc3ffff).rom().region("user1", 0);
@@ -658,6 +661,8 @@ MACHINE_CONFIG_START(decstation_state::kn01)
 	TIMER(config, m_scantimer, 0);
 	m_scantimer->configure_scanline(FUNC(decstation_state::scanline_timer), "screen", 0, 1);
 
+	DC7085(config, m_dz, 0);
+
 	AM79C90(config, m_lance, XTAL(12'500'000));
 
 	MC146818(config, m_rtc, XTAL(32'768));